Trial Outcomes & Findings for Efficacy, Safety and Immunogenicity Study of GlaxoSmithKline(GSK) Biologicals' Candidate Malaria Vaccine 257049 in the Sporozoite Challenge Model in Healthy Malaria-naïve Adults (NCT NCT01857869)

Last Updated: 2019-06-26

Results Overview

The definition of malaria for primary and secondary efficacy outcomes is the appearance of asexual blood stage P. falciparum parasites detected by blood slide at any time post challenge/rechallenge up to 28 days.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

64 participants

Primary outcome timeframe

28 days post-challenge (Study Day 245)

Results posted on

2019-06-26

Participant Flow

Out of the 64 subjects originally enrolled in the study, 1 subject was not included in the Intention-to-Treat Cohort. The design of the study included 4 epochs (see pre-assignment details).

Primary Phase (screening, vaccination \[delayed fractional dose group and 0, 1, 2-month group\] \& challenge): Study Day (D) 217 to D245 - Follow-up: D259 to D376 - Booster (Bst) Phase (re-screening \[delayed fractional dose group and 0, 1, 2-month group\], vaccination \& re-challange): Bst Phase Study D20 to D49 - Follow-up: Bst Phase Study D77 to D105.

Participant milestones

Participant milestones
Measure	GSK257049-0,1,7M Group Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (controlled human malaria infection \[CHMI\]).	GSK257049-0,1,2M Group Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,7M P-NoBo Group Subjects from GSK257049-0,1,7M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallenge.	GSK257049-0,1,7M P-Bo Group Subjects from GSK257049-0,1,7M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,7M NP-Bo Group Subjects from GSK257049-0,1,7M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Primary/Challenge Phase STARTED	34	17	12	0	0	0	0	0	0	0
Primary/Challenge Phase COMPLETED	29	16	12	0	0	0	0	0	0	0
Primary/Challenge Phase NOT COMPLETED	5	1	0	0	0	0	0	0	0	0
Booster/Rechallenge Phase STARTED	0	0	0	9	10	2	5	4	3	6
Booster/Rechallenge Phase COMPLETED	0	0	0	7	10	2	5	4	3	6
Booster/Rechallenge Phase NOT COMPLETED	0	0	0	2	0	0	0	0	0	0

Reasons for withdrawal

Reasons for withdrawal
Measure	GSK257049-0,1,7M Group Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (controlled human malaria infection \[CHMI\]).	GSK257049-0,1,2M Group Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	GSK257049-0,1,7M P-NoBo Group Subjects from GSK257049-0,1,7M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallenge.
Primary/Challenge Phase Lost to Follow-up	2	0	0
Primary/Challenge Phase Pregnancy	1	0	0
Primary/Challenge Phase Protocol Violation	1	0	0
Primary/Challenge Phase Other	1	1	0
Booster/Rechallenge Phase Withdrawal by Subject	0	0	1
Booster/Rechallenge Phase Volunteer took antibiotic pre-challenge	0	0	1

Baseline Characteristics

This baseline measure refers to the Primary/challenge phase population.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,7M P-NoBo Group n=7 Participants Subjects from GSK257049-0,1,7M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallenge.	GSK257049-0,1,7M P-Bo Group n=10 Participants Subjects from GSK257049-0,1,7M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,7M NP-Bo Group n=2 Participants Subjects from GSK257049-0,1,7M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-NoBo Group n=5 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=4 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up n=6 Participants Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.	Total n=100 Participants Total of all reporting groups
Age, Continuous	34.4 Years STANDARD_DEVIATION 8.6 • n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	30.1 Years STANDARD_DEVIATION 7.9 • n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	36.4 Years STANDARD_DEVIATION 8.7 • n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	33.6 Years STANDARD_DEVIATION 8.6 • n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Sex: Female, Male Female	15 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	6 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	7 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	28 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Sex: Female, Male Male	19 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	11 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	5 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	35 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Race/Ethnicity, Customized Geographic ancestry · African Heritage/African American	15 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	5 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	5 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	25 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Race/Ethnicity, Customized Geographic ancestry · Asian - Central/South Asian Heritage	1 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	0 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	0 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	1 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Race/Ethnicity, Customized Geographic ancestry · Asian - South East Asian Heritage	2 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	0 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	0 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	2 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Race/Ethnicity, Customized Geographic ancestry · White - Caucasian/European Heritage	13 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	10 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	5 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	28 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.
Race/Ethnicity, Customized Geographic ancestry · Unspecified	3 Participants n=34 Participants • This baseline measure refers to the Primary/challenge phase population.	2 Participants n=17 Participants • This baseline measure refers to the Primary/challenge phase population.	2 Participants n=12 Participants • This baseline measure refers to the Primary/challenge phase population.	—	—	—	—	—	—	—	7 Participants n=63 Participants • This baseline measure refers to the Primary/challenge phase population.

PRIMARY outcome

Timeframe: 28 days post-challenge (Study Day 245)

Population: The analysis was based on the According-to-Protocol (ATP) population for immunogenicity and efficacy, which included all subjects who complied with the protocol requirements and underwent P. falciparum CHMI.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=30 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Plasmodium Falciparum Parasitemia Defined by a Positive Blood Slide, Following Sporozoite Challenge	4 Participants	6 Participants	12 Participants	—	—	—	—

SECONDARY outcome

Timeframe: Up to 28 days post-challenge (Study Day 245)

Population: The analysis was based on the ATP population for immunogenicity and efficacy, which included all subjects who complied with the protocol requirements and underwent P. falciparum CHMI. This analysis included those subjects with a positive blood slide.

The time to onset was expressed in days. The definition of malaria infection for primary and secondary efficacy outcomes is the appearance of asexual blood stage P. falciparum parasites detected by blood slide at any time post challenge/rechallenge up to 28 days.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=4 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=6 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Time to Onset of P. Falciparum Parasitemia Infection Defined by a Positive Blood Slide, Following Sporozoite Challenge	17 Days Standard Deviation 6	15 Days Standard Deviation 5	13 Days Standard Deviation 1	—	—	—	—

SECONDARY outcome

Timeframe: Up to 28 days post rechallenge (Booster Phase Day 49)

Population: The analysis was based on the ATP population for immunogenicity and efficacy for the rechallenge Phase, which included all subjects from the ATP population for immunogenicity and efficacy who consented to the rechallenge.

The definition of malaria infection for primary and secondary efficacy outcomes is the appearance of asexual blood stage P. falciparum parasites detected by blood slide at any time post challenge/rechallenge up to 28 days.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=7 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=10 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=2 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group n=5 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=4 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up n=6 Participants Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Plasmodium Falciparum Parasitemia Defined by a Positive Blood Slide, Following Sporozoite Rechallenge	4 Participants	1 Participants	0 Participants	4 Participants	3 Participants	1 Participants	6 Participants

SECONDARY outcome

Timeframe: Up to 28 days post rechallenge (Booster Phase Day 49)

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=4 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=1 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=4 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=1 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=6 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Time to Onset of P. Falciparum Parasitemia Infection Defined by a Positive Blood Slide, Following Sporozoite Rechallenge	14 Days Standard Deviation 1	14 Days Standard Deviation 0	15 Days Standard Deviation 1	14 Days Standard Deviation 2	14 Days Standard Deviation 0	12 Days Standard Deviation 1	—

SECONDARY outcome

Timeframe: 7 days before vaccination (D-7), post-dose 1 at Day 28, post-dose 2 at Days 42, 56, 98, 196, at DoC Primary Phase (PP) (Day of CHMI = Day 217), at DoC PP (Day 217) + 7, 14, 28, 42, 56, 70, 84, 159 days (Days 224, 231, 245, 259, 273, 287, 301, 376).

Population: The analysis was based on the ATP population for immunogenicity and efficacy, which included all subjects who complied with the protocol requirements and underwent P. falciparum CHMI.

Anti-CS antibody concentrations were determined by Enzyme Linked Immunosorbent Assay (ELISA) and expressed as EU/mL.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=30 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations 7 days before vaccination	0.3 EU/mL Interval 0.2 to 0.3	0.3 EU/mL Interval 0.3 to 0.3	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At Day 28	13.1 EU/mL Interval 6.9 to 25.1	16.3 EU/mL Interval 8.0 to 33.2	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At Day 42	104.2 EU/mL Interval 76.0 to 142.7	64.4 EU/mL Interval 34.1 to 121.8	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At Day 56	83.3 EU/mL Interval 59.1 to 117.5	57.9 EU/mL Interval 30.7 to 109.4	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At Day 98	46.1 EU/mL Interval 30.4 to 69.7	—	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At Day 196	18.3 EU/mL Interval 11.3 to 29.6	—	—	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations At DoC PP (Day 217)	75.2 EU/mL Interval 57.8 to 97.8	100.1 EU/mL Interval 63.5 to 157.8	0.4 EU/mL Interval 0.2 to 0.8	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 7 after DoC PP (Day 217)	75.7 EU/mL Interval 57.3 to 100.0	91.7 EU/mL Interval 57.5 to 146.2	0.4 EU/mL Interval 0.2 to 0.8	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 14 after DoC PP (Day 217)	68.9 EU/mL Interval 51.8 to 91.6	79.4 EU/mL Interval 48.5 to 130.0	0.4 EU/mL Interval 0.2 to 0.8	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 28 after DoC PP (Day 217)	63.8 EU/mL Interval 46.8 to 87.0	75.7 EU/mL Interval 45.8 to 125.2	0.5 EU/mL Interval 0.3 to 1.0	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 42 after DoC PP (Day 217)	57.6 EU/mL Interval 42.3 to 78.5	73.6 EU/mL Interval 45.3 to 119.7	0.6 EU/mL Interval 0.3 to 1.1	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 56 after DoC PP (Day 217)	54.0 EU/mL Interval 38.9 to 75.0	63.2 EU/mL Interval 34.9 to 114.3	0.5 EU/mL Interval 0.3 to 1.0	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 70 after DoC PP (Day 217)	46.9 EU/mL Interval 33.0 to 66.5	59.2 EU/mL Interval 35.1 to 99.8	0.5 EU/mL Interval 0.3 to 1.0	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 84 after DoC PP (Day 217)	45.6 EU/mL Interval 32.1 to 64.8	55.3 EU/mL Interval 34.4 to 88.9	0.5 EU/mL Interval 0.3 to 1.0	—	—	—	—
Anti-circumsporozoite (Anti-CS) Repeat Region Antibody Concentrations Day 159 after DoC PP (Day 217)	32.8 EU/mL Interval 22.1 to 48.6	34.6 EU/mL Interval 20.9 to 57.0	0.5 EU/mL Interval 0.3 to 1.0	—	—	—	—

SECONDARY outcome

Timeframe: At Day 0 of rechallenge (pre-booster dose) and at DoC PP (Day 217 = Day of rechallenge)

Anti-CS antibody concentrations were determined by Enzyme Linked Immunosorbent Assay (ELISA) and expressed as EU/mL.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=7 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=10 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=2 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group n=5 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=4 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up n=6 Participants Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Anti-CS Repeat Region Antibody Concentrations for the Rechallenge Phase At DoC PP (Day 217)	25.7 EU/mL Interval 10.3 to 64.5	86.6 EU/mL Interval 52.0 to 144.1	81.2 EU/mL Interval 0.0 to 660120.7	39.2 EU/mL Interval 17.2 to 89.4	61.7 EU/mL Interval 13.0 to 292.4	53.5 EU/mL Interval 12.3 to 231.6	0.3 EU/mL Interval 0.2 to 0.4
Anti-CS Repeat Region Antibody Concentrations for the Rechallenge Phase At Day 0 of rechallenge	—	30.7 EU/mL Interval 13.0 to 72.1	7.2 EU/mL Interval 0.0 to 44283115.0	—	35.9 EU/mL Interval 15.8 to 81.7	24.5 EU/mL Interval 1.8 to 334.0	—

SECONDARY outcome

Timeframe: 7 days before vaccination (D-7), post-dose 1 at Day 14, post-dose 2 at Day 42, at DoC PP (Day of CHMI = Day 217), at DoC PP (Day 217) + 7, 28, 84, 159 days (Days 224, 245, 301, 376).

Frequency of Cluster of Differentiation 4 (CD4) polypositives T-cells with at least 2 cytokines/activation markers between CD40-Ligand (CD40-L), interferon gamma (INF-g), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-a) was assessed for peripheral blood mononuclear cells (PBMC) with intracellular cytokine staining (ICS).

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=29 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells Day 7 after DoC PP (Day 217)	661.61 CD4+ T-cells/million CD4 T-cells Standard Deviation 711.86	539.40 CD4+ T-cells/million CD4 T-cells Standard Deviation 416.68	39.25 CD4+ T-cells/million CD4 T-cells Standard Deviation 42.40	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells Day 84 after DoC PP (Day 217)	481.44 CD4+ T-cells/million CD4 T-cells Standard Deviation 392.44	472.63 CD4+ T-cells/million CD4 T-cells Standard Deviation 287.64	90.67 CD4+ T-cells/million CD4 T-cells Standard Deviation 121.47	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells 7 days before vaccination	61.38 CD4+ T-cells/million CD4 T-cells Standard Deviation 95.16	83.31 CD4+ T-cells/million CD4 T-cells Standard Deviation 79.40	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells At Day 14	168.89 CD4+ T-cells/million CD4 T-cells Standard Deviation 205.87	242.53 CD4+ T-cells/million CD4 T-cells Standard Deviation 262.97	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells At Day 42	1306.11 CD4+ T-cells/million CD4 T-cells Standard Deviation 1962.03	866.87 CD4+ T-cells/million CD4 T-cells Standard Deviation 779.25	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells At DoC PP (Day 217)	596.15 CD4+ T-cells/million CD4 T-cells Standard Deviation 636.60	555.86 CD4+ T-cells/million CD4 T-cells Standard Deviation 487.16	57.17 CD4+ T-cells/million CD4 T-cells Standard Deviation 102.19	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells Day 28 after DoC PP (Day 217)	626.29 CD4+ T-cells/million CD4 T-cells Standard Deviation 586.16	472.63 CD4+ T-cells/million CD4 T-cells Standard Deviation 287.64	162.22 CD4+ T-cells/million CD4 T-cells Standard Deviation 275.51	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific Cluster of Differentiation 4 (CD4) T-cells Day 159 after DoC PP (Day 217)	490.00 CD4+ T-cells/million CD4 T-cells Standard Deviation 401.39	307.87 CD4+ T-cells/million CD4 T-cells Standard Deviation 231.91	32.55 CD4+ T-cells/million CD4 T-cells Standard Deviation 51.06	—	—	—	—

SECONDARY outcome

Timeframe: 7 days before vaccination (D-7), post-dose 1 at Day 14, post-dose 2 at Day 42, at DoC PP (Day of CHMI = Day 217), at DoC PP (Day 217) + 7, 28, 84, 159 days (Days 224, 245, 301, 376).

Frequency of CD8 polypositives T-cells with at least 2 cytokines/activation markers between CD40-L, INF-g, IL-2 and TNF-a was assessed for PBMC with ICS.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=29 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells 7 days before vaccination	14.10 CD8+ T-cells/million CD8 T-cells Standard Deviation 20.60	9.56 CD8+ T-cells/million CD8 T-cells Standard Deviation 15.31	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells At Day 14	24.61 CD8+ T-cells/million CD8 T-cells Standard Deviation 43.01	17.20 CD8+ T-cells/million CD8 T-cells Standard Deviation 30.03	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells At Day 42	18.7 CD8+ T-cells/million CD8 T-cells Standard Deviation 46.69	27.60 CD8+ T-cells/million CD8 T-cells Standard Deviation 40.40	—	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells At DoC PP (Day 217)	32.52 CD8+ T-cells/million CD8 T-cells Standard Deviation 57.64	28.86 CD8+ T-cells/million CD8 T-cells Standard Deviation 28.73	15.33 CD8+ T-cells/million CD8 T-cells Standard Deviation 29.06	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells Day 7 after DoC PP (Day 217)	19.54 CD8+ T-cells/million CD8 T-cells Standard Deviation 42.55	32.07 CD8+ T-cells/million CD8 T-cells Standard Deviation 56.77	32.00 CD8+ T-cells/million CD8 T-cells Standard Deviation 53.81	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells Day 28 after DoC PP (Day 217)	19.96 CD8+ T-cells/million CD8 T-cells Standard Deviation 27.35	34.81 CD8+ T-cells/million CD8 T-cells Standard Deviation 66.56	17.67 CD8+ T-cells/million CD8 T-cells Standard Deviation 36.31	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells Day 84 after DoC PP (Day 217)	19.89 CD8+ T-cells/million CD8 T-cells Standard Deviation 54.19	20.23 CD8+ T-cells/million CD8 T-cells Standard Deviation 26.25	12.17 CD8+ T-cells/million CD8 T-cells Standard Deviation 22.91	—	—	—	—
Frequency of CS Repeat and T-cell Epitope (RT)-Specific CD8 T-cells Day 159 after DoC PP (Day 217)	26.74 CD8+ T-cells/million CD8 T-cells Standard Deviation 52.22	24.40 CD8+ T-cells/million CD8 T-cells Standard Deviation 44.30	22.00 CD8+ T-cells/million CD8 T-cells Standard Deviation 33.01	—	—	—	—

SECONDARY outcome

Timeframe: 7 days before vaccination (D-7), post-dose 1 at Day 28, post-dose 2 at Days 42, 56, 98, 196 after first dose, at DoC PP (Day of CHMI = Day 217), at DoC PP (Day 217)+ 7, 14, 28, 42, 56, 70, 84, 159 days (Days 224, 231, 245, 259, 273, 287, 301, 376).

Population: The analysis was based on the ATP population for immunogenicity and efficacy, which included all subjects who complied with the protocol requirements and underwent P. falciparum CHMI.

Anti-HBs antibody concentrations were determined by Chemiluminometric Immunoassay (CLIA) and expressed as miliinternation units per mililier (mIU/mL).

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=30 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) 7 days before vaccination	27.5 mIU/mL Interval 11.4 to 66.0	28.5 mIU/mL Interval 7.1 to 113.9	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At Day 28	7223.0 mIU/mL Interval 1437.5 to 36292.7	7318.2 mIU/mL Interval 643.5 to 83221.5	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At Day 42	35016.9 mIU/mL Interval 14549.0 to 84279.4	27205.5 mIU/mL Interval 5504.0 to 134473.9	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At Day 56	21013.0 mIU/mL Interval 8181.7 to 53967.5	20625.8 mIU/mL Interval 3809.7 to 111668.5	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At Day 98	12367.7 mIU/mL Interval 5159.9 to 29643.9	—	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At Day 196	9917.0 mIU/mL Interval 4447.7 to 22111.9	—	—	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) At DoC PP (Day 217)	33715.4 mIU/mL Interval 20777.5 to 54709.5	31798.7 mIU/mL Interval 8809.6 to 114779.3	27.9 mIU/mL Interval 6.6 to 118.1	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 7 after DoC PP (Day 217)	29902.6 mIU/mL Interval 18090.1 to 49428.5	28989.2 mIU/mL Interval 7097.6 to 118403.1	32.5 mIU/mL Interval 7.3 to 145.1	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 14 after DoC PP (Day 217)	35401.1 mIU/mL Interval 20513.7 to 61092.8	24952.2 mIU/mL Interval 6402.7 to 97242.0	25.7 mIU/mL Interval 6.4 to 103.0	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 28 after DoC PP (Day 217)	25553.8 mIU/mL Interval 14413.9 to 45303.2	25944.1 mIU/mL Interval 7496.3 to 89790.9	27.5 mIU/mL Interval 6.5 to 116.4	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 42 after DoC PP (Day 217)	23757.6 mIU/mL Interval 13130.3 to 42986.3	20000.3 mIU/mL Interval 5110.6 to 78271.6	32.8 mIU/mL Interval 7.3 to 146.6	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 56 after DoC PP (Day 217)	25917.3 mIU/mL Interval 14012.2 to 47937.4	23199.5 mIU/mL Interval 5472.8 to 98343.4	34.6 mIU/mL Interval 7.7 to 155.2	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 70 after DoC PP (Day 217)	23722.4 mIU/mL Interval 12431.5 to 45268.1	23313.8 mIU/mL Interval 6098.3 to 89128.6	31.9 mIU/mL Interval 7.3 to 139.8	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 84 after DoC PP (Day 217)	19155.1 mIU/mL Interval 10713.8 to 34247.0	19631.5 mIU/mL Interval 6184.8 to 62313.2	26.3 mIU/mL Interval 6.5 to 106.5	—	—	—	—
Antibody Concentrations Against Hepatitis B Surface Antigen (Anti-HBs) Day 159 after DoC PP (Day 217)	14459.9 mIU/mL Interval 7702.5 to 27145.8	13495.2 mIU/mL Interval 3956.7 to 46028.2	26.2 mIU/mL Interval 6.5 to 106.0	—	—	—	—

SECONDARY outcome

Timeframe: At Day 0 of rechallenge (pre-booster dose) and at DoC PP (Day 217 = Day of rechallenge)

Anti-HBs antibody concentrations were determined by Chemiluminometric Immunoassay (CLIA).

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=7 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=10 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=2 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group n=5 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=4 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up n=6 Participants Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Anti-HBs Antibody Concentrations for Rechallenge Phase At Day 9 of rechallenge	—	9270.9 mIU/mL Interval 3019.1 to 28468.3	6928.3 mIU/mL Interval 0.0 to 280600000000000.0	—	23259.5 mIU/mL Interval 5399.6 to 100192.6	15620.0 mIU/mL Interval 268.0 to 910369.4	—
Anti-HBs Antibody Concentrations for Rechallenge Phase At DoC PP (Day 217)	19592.4 mIU/mL Interval 5063.3 to 75812.3	24261.5 mIU/mL Interval 10414.9 to 56517.5	36809.8 mIU/mL Interval 0.0 to 631600000000.0	6051.9 mIU/mL Interval 340.9 to 107425.7	38175.5 mIU/mL Interval 12828.4 to 113604.9	34470.4 mIU/mL Interval 6909.0 to 171979.3	35.7 mIU/mL Interval 3.8 to 335.7

SECONDARY outcome

Timeframe: Post-dose 1 at Day 28, post-dose 2 at Days 56, and 196, DoC PP (DoC = the day of CHMI, Day 217), DoC PP (Day 217) + 84 days (Day 301) and DoC PP (Day 217) +159 days (Day 376)

Population: The analysis was based on the ATP population for immunogenicity and efficacy, which included all subjects who complied with the protocol requirements and underwent P. falciparum CHMI.

The avidity index percentage was calculated by anti-CS repeat region concentration under chaotropic reagent/anti-CS repeat region concentration without chaotropic reagent. The median and inter-quartile (Q1 and Q3) range was reported at the prespecified time-points.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=30 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=2 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase At Day 28	25.65 Avidity index Interval 16.3 to 40.5	17.90 Avidity index Interval 8.3 to 27.8	—	—	—	—	—
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase At Day 56	37.40 Avidity index Interval 28.5 to 45.1	31.10 Avidity index Interval 19.85 to 33.5	—	—	—	—	—
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase At Day 196	28.10 Avidity index Interval 19.4 to 40.1	—	—	—	—	—	—
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase At DoC PP (Day 217)	40.40 Avidity index Interval 31.8 to 49.6	29.00 Avidity index Interval 22.4 to 34.05	—	—	—	—	—
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase Day 84 after DoC PP (Day 217)	37.40 Avidity index Interval 32.5 to 44.0	28.30 Avidity index Interval 18.7 to 31.5	32.10 Avidity index Interval 20.5 to 43.7	—	—	—	—
Anti-CS Repeat Region Immunoglobulin G (IgG) Avidity Index for the Challenge Phase Day 159 after DoC PP (Day 217)	36.10 Avidity index Interval 30.6 to 43.8	28.90 Avidity index Interval 19.6 to 32.7	32.05 Avidity index Interval 21.9 to 42.2	—	—	—	—

SECONDARY outcome

Timeframe: Pre-booster dose (Booster phase Day 0) and at DoC Booster/rechallenge phase (Day of Controlled Human Malaria Infection - Day 21)

Population: The analysis was based on the ATP population for immunogenicity and efficacy for the rechallenge, which included all subjects from the ATP population for immunogenicity and efficacy who consented to the rechallenge. Results were not reported for the Control Group Follow-up, since subjects from this group did not receive any immunization.

The avidity index percentage was calculated by anti-CS repeat region titer under chaotropic reagent/anti-CS repeat region titer without chaotropic reagent. The median and inter-quartile (Q1 and Q3) range was reported at the prespecified time-points.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=7 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=10 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=2 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group n=5 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group n=4 Participants Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group n=3 Participants Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Anti-CS Repeat Region IgG Avidity Index for the Rechallenge Phase Pre-booster dose	—	41.15 Avidity index Interval 27.1 to 48.4	43.30 Avidity index Interval 38.6 to 48.0	—	21.25 Avidity index Interval 12.95 to 32.05	30.40 Avidity index Interval 15.5 to 34.7	—
Anti-CS Repeat Region IgG Avidity Index for the Rechallenge Phase DoC Booster/rechallenge phase (Day 21)	35.00 Avidity index Interval 30.4 to 44.1	46.55 Avidity index Interval 44.6 to 51.8	50.60 Avidity index Interval 44.7 to 56.5	31.30 Avidity index Interval 22.8 to 38.6	36.80 Avidity index Interval 21.8 to 39.65	31.20 Avidity index Interval 23.2 to 40.9	—

SECONDARY outcome

Timeframe: Within the 7-day (Days 0-6) post-vaccination period following each dose and across doses

Population: The analysis was based on the Intention-to-Treat (ITT) population, which included all subjects with at least one vaccine administration documented, who had their symptom sheets filled in. Results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.

Assessed solicited local symptoms were pain, redness and swelling. Any = occurrence of the symptom regardless of intensity grade. Grade 3 pain = significant pain at rest, that prevented normal activity. Grade 3 redness/swelling = redness/swelling spreading beyond 100 millimeters (mm) of injection site.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Swelling, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Pain, Across doses	32 Participants	16 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Pain, Dose 1	30 Participants	16 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Pain, Dose 1	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Redness, Dose 1	7 Participants	8 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Redness, Dose 1	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Swelling, Dose 1	8 Participants	1 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Swelling, Dose 1	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Pain, Dose 2	28 Participants	13 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Pain, Dose 2	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Redness, Dose 2	13 Participants	6 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Redness, Dose 2	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Swelling, Dose 2	10 Participants	2 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Swelling, Dose 2	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Pain, Dose 3	21 Participants	12 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Pain, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Redness, Dose 3	23 Participants	7 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Redness, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Swelling, Dose 3	17 Participants	3 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Pain, Across doses	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Redness, Across doses	26 Participants	12 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Redness, Across doses	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Swelling, Across doses	21 Participants	4 Participants	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Swelling, Across doses	0 Participants	0 Participants	—	—	—	—	—

SECONDARY outcome

Timeframe: Within the 7-day (Days 0-6) post-vaccination period following each dose and across doses

Population: The analysis was based on the ITT population, which included all subjects with at least one vaccine administration documented, who had their symptom sheets filled in. Results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.

Assessed solicited general symptoms were fatigue, gastrointestinal symptoms (nausea, vomiting and/or abdominal pain), headache and fever \[defined as axillary temperature equal to or above (≥) 38.0 degrees Celsius (°C)\]. Any = occurrence of the symptom regardless of intensity grade. Grade 3 symptom = symptom that prevented normal activity. Grade 3 fever = fever ≥ 39.0 °C. Related = symptom assessed by the investigator as related to the vaccination.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Gastrointestinal symptoms, Dose 1	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Temperature, Dose 1	3 Participants	3 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Temperature, Dose 1	3 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Fatigue, Dose 2	15 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Fatigue, Dose 2	1 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Headache, Across doses	18 Participants	11 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Fatigue, Dose 1	10 Participants	3 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Fatigue, Dose 1	9 Participants	3 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Fatigue, Dose 1	1 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Gastrointestinal symptoms, Dose 1	4 Participants	2 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Gastrointestinal symptoms, Dose 1	4 Participants	2 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Headache, Dose 1	9 Participants	9 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Headache, Dose 1	8 Participants	9 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Headache, Dose 1	1 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Temperature, Dose 1	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Fatigue, Dose 2	15 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Gastrointestinal symptoms, Dose 2	3 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Gastrointestinal symptoms, Dose 2	3 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Gastrointestinal symptoms, Dose 2	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Headache, Dose 2	15 Participants	9 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Headache, Dose 2	15 Participants	8 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Headache, Dose 2	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Temperature, Dose 2	6 Participants	1 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Temperature, Dose 2	6 Participants	1 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Temperature, Dose 2	3 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Fatigue, Dose 3	8 Participants	7 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Fatigue, Dose 3	8 Participants	6 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Fatigue, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Gastrointestinal symptoms, Dose 3	6 Participants	2 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Gastrointestinal symptoms, Dose 3	3 Participants	2 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Gastrointestinal symptoms, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Headache, Dose 3	9 Participants	6 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Headache, Dose 3	7 Participants	6 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Headache, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Temperature, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Temperature, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Temperature, Dose 3	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Fatigue, Across doses	18 Participants	9 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Fatigue, Across doses	18 Participants	8 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Fatigue, Across doses	2 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Gastrointestinal symptoms, Across doses	7 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Gastrointestinal symptoms, Across doses	7 Participants	5 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Gastrointestinal symptoms, Across doses	0 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Headache, Across doses	18 Participants	11 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Headache, Across doses	1 Participants	0 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Temperature, Across doses	8 Participants	4 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Temperature, Across doses	8 Participants	1 Participants	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Temperature, Across doses	3 Participants	0 Participants	—	—	—	—	—

SECONDARY outcome

Timeframe: Within the 7-day (Days 0-6) post- booster vaccination period

Population: The analysis was based on the ITT population for the rechallenge, which included subjects from the ITT population consenting to the rechallenge. For the purpose of the analysis, subjects who received a low fractional formulation booster dose of GSK257049 vaccine have been pooled into a single group and results were tabulated accordingly.

Assessed solicited local symptoms were pain, redness and swelling. Any = occurrence of the symptom regardless of intensity grade. Grade 3 pain = pain that prevented normal activity. Grade 3 redness/swelling = redness/swelling spreading beyond 100 millimeters (mm) of injection site.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=19 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Pain	11 Participants	—	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Pain	0 Participants	—	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Redness	8 Participants	—	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Redness	0 Participants	—	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Any Swelling	4 Participants	—	—	—	—	—	—
Number of Subjects With Any and Grade 3 Solicited Local Symptoms Grade 3 Swelling	0 Participants	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Within the 7-day (Days 0-6) post- booster vaccination period

Assessed solicited general symptoms were fatigue, gastrointestinal symptoms, headache and fever \[defined as axillary temperature equal to or above (≥) 38.0 degrees Celsius (°C)\]. Any = occurrence of the symptom regardless of intensity grade. Grade 3 symptom = symptom that prevented normal activity. Grade 3 fever = fever ≥ 39.0 °C. Related = symptom assessed by the investigator as related to the vaccination.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=19 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Fatigue	8 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Fatigue	5 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Fatigue	0 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Gastrointestinal symptoms	4 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Gastrointestinal symptoms	3 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Gastrointestinal symptoms	0 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Headache	8 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Headache	6 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Headache	1 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Any Temperature	0 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Related Temperature	0 Participants	—	—	—	—	—	—
Number of Subjects With Any, Grade 3 and Related Solicited General Symptoms Grade 3 Temperature	0 Participants	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Within 30-days (Days 0-29) post-primary vaccination

Population: The analysis was based on the ITT population, which included all subjects with at least one vaccine administration documented. Results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.

An unsolicited AE covers any untoward medical occurrence in a clinical investigation subject temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product and reported in addition to those solicited during the clinical study and any solicited symptom with onset outside the specified period of follow-up for solicited symptoms. Any was defined as the occurrence of any unsolicited AE regardless of intensity grade or relation to vaccination.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any Unsolicited Adverse Events (AEs)	25 Participants	16 Participants	—	—	—	—	—

SECONDARY outcome

Timeframe: Within 30-days (Days 0-29) post- booster vaccination

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=19 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any Unsolicited Adverse Events (AEs)	10 Participants	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Within 30-days (Days 0-29) post-first CHMI

Population: The analysis was based on the ITT population, which included all subjects with at least one vaccine administration documented and who had post-first CHMI available results.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=30 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=16 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any Unsolicited Adverse Events (AEs)	25 Participants	13 Participants	12 Participants	—	—	—	—

SECONDARY outcome

Timeframe: Within 30-days (Days 0-29) post- second CHMI

Population: The analysis was based on the ITT population for the rechallenge, which included subjects from the ITT population consenting to the rechallenge.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=12 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=19 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=6 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Any Unsolicited Adverse Events (AEs)	11 Participants	15 Participants	6 Participants	—	—	—	—

SECONDARY outcome

Timeframe: From study start to end of Primary Phase (Study Day 245)

Population: The analysis was based on the ITT population, which included all subjects with at least one vaccine administration documented.

Serious adverse events (SAEs) assessed include medical occurrences that result in death, are life threatening, require hospitalization or prolongation of hospitalization or result in disability/incapacity.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Serious Adverse Events (SAEs)	1 Participants	0 Participants	0 Participants	—	—	—	—

SECONDARY outcome

Timeframe: During the entire study period (Up to Day 105 of Booster Phase)

Population: The analysis was based on the ITT population, which included all subjects with at least one vaccine administration documented.

Outcome measures

Outcome measures
Measure	GSK257049-0,1,7M Group n=34 Participants Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 Participants Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 Participants Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M P-NoBo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received no booster dose (NoBo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M P-Bo Group Subjects from GSK257049-0,1,2M Group who were protected (P) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	GSK257049-0,1,2M NP-Bo Group Subjects from GSK257049-0,1,2M Group who were not protected (NP) during first CHMI and who received a booster fractional low-formulated (Bo) of GSK257049 vaccine and underwent sporozoite rechallange.	Control Group Follow-up Subjects from Control Group in Primary Phase who remained uninfected with P. falciparum malaria and enrolled as infectivity controls for Follow-up Phase to undergo sporozoite rechallange.
Number of Subjects With Serious Adverse Events (SAEs)	1 Participants	0 Participants	0 Participants	—	—	—	—

Adverse Events

GSK257049-0,1,7M Group

Serious events: 1 serious events

Other events: 34 other events

Deaths: 0 deaths

GSK257049-0,1,2M Group

Serious events: 0 serious events

Other events: 17 other events

Deaths: 0 deaths

Infectivity Control Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	GSK257049-0,1,7M Group n=34 participants at risk Subjects receiving 2 doses of GSK257049 vaccine given at 0 and 1 months and followed 6 months later (At Month 7) by a fractional dose of GSK257049 vaccine and underwent sporozoite challenge (CHMI).	GSK257049-0,1,2M Group n=17 participants at risk Subjects receiving 3 doses of GSK257049 vaccine given one month apart (0,1 and 2 months) and underwent sporozoite challenge (CHMI).	Infectivity Control Group n=12 participants at risk Volunteers who did not receive any immunization but underwent sporozoite challenge (CHMI).
Injury, poisoning and procedural complications Alcohol poisoning	2.9% 1/34 • Number of events 1 • Solicited local and general symptoms: within 7 days (Days 0-6) post-orimary vaccination. Unsolicited adverse events (AEs): within 30 days (Days 0-29) post-primary vaccination and post-CHMI. Serious adverse events (SAEs): during the entire study period (up to Day 105 of Booster Phase). Solicited and Unsolicited results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.	0.00% 0/17 • Solicited local and general symptoms: within 7 days (Days 0-6) post-orimary vaccination. Unsolicited adverse events (AEs): within 30 days (Days 0-29) post-primary vaccination and post-CHMI. Serious adverse events (SAEs): during the entire study period (up to Day 105 of Booster Phase). Solicited and Unsolicited results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.	0.00% 0/12 • Solicited local and general symptoms: within 7 days (Days 0-6) post-orimary vaccination. Unsolicited adverse events (AEs): within 30 days (Days 0-29) post-primary vaccination and post-CHMI. Serious adverse events (SAEs): during the entire study period (up to Day 105 of Booster Phase). Solicited and Unsolicited results were not reported for the Infectivity Control Group, since subjects from this group did not receive any immunization.

Other adverse events

Additional Information

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Principal investigator is a sponsor employee GSK agreements may vary with individual investigators, but will not prohibit any investigator from publishing. GSK supports the publication of results from all centers of a multi-center trial but requests that reports based on single-site data not precede the primary publication of the entire clinical trial.
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Restriction type: OTHER