Trial Outcomes & Findings for Efficacy of Na-GST-1/Alhydrogel Hookworm Vaccine Assessed by Controlled Challenge Infection (NCT NCT03172975)

Last Updated: 2025-12-05

Results Overview

Proportion of subjects with detectable hookworm eggs, at any time point, in fecal samples, as determined by microscopy using the qualified saline flotation technique

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

39 participants

Primary outcome timeframe

On Study Days 175, 182, 189, 203, 217, 231, 245, 259, 273, and 280.

Results posted on

2025-12-05

Participant Flow

Recruitment and enrollment occurred on an ongoing basis, with each group being recruited and vaccinated in parallel. Participants were enrolled sequentially and upon enrollment were randomized to one of the four groups.

Participant milestones

Participant milestones
Measure	Na-GST-1/Alhydrogel 100 µg Na-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 100 µg Na-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + GLA-AF 100 µg Na-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Overall Study STARTED	10	9	10	10
Overall Study COMPLETED	9	5	10	8
Overall Study NOT COMPLETED	1	4	0	2

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Efficacy of Na-GST-1/Alhydrogel Hookworm Vaccine Assessed by Controlled Challenge Infection

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Na-GST-1/Alhydrogel n=10 Participants 100 µg Na-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg Na-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg Na-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Total n=39 Participants Total of all reporting groups
Age, Continuous	26.1 Years STANDARD_DEVIATION 4.6 • n=37 Participants	30.4 Years STANDARD_DEVIATION 8.2 • n=37 Participants	24.7 Years STANDARD_DEVIATION 3.3 • n=74 Participants	26.1 Years STANDARD_DEVIATION 3.45 • n=267 Participants	26.7 Years STANDARD_DEVIATION 5.4 • n=272 Participants
Age, Customized Age, Continuous	25.5 Years n=37 Participants	29.0 Years n=37 Participants	23.5 Years n=74 Participants	25.5 Years n=267 Participants	26.0 Years n=272 Participants
Sex: Female, Male Female	4 Participants n=37 Participants	5 Participants n=37 Participants	6 Participants n=74 Participants	7 Participants n=267 Participants	22 Participants n=272 Participants
Sex: Female, Male Male	6 Participants n=37 Participants	4 Participants n=37 Participants	4 Participants n=74 Participants	3 Participants n=267 Participants	17 Participants n=272 Participants
Race/Ethnicity, Customized Race · American Indian or Alaska Native	0 Participants n=37 Participants	1 Participants n=37 Participants	0 Participants n=74 Participants	0 Participants n=267 Participants	1 Participants n=272 Participants
Race/Ethnicity, Customized Race · Asian	0 Participants n=37 Participants	0 Participants n=37 Participants	4 Participants n=74 Participants	1 Participants n=267 Participants	5 Participants n=272 Participants
Race/Ethnicity, Customized Race · Black or African American	1 Participants n=37 Participants	1 Participants n=37 Participants	0 Participants n=74 Participants	1 Participants n=267 Participants	3 Participants n=272 Participants
Race/Ethnicity, Customized Race · Other	1 Participants n=37 Participants	2 Participants n=37 Participants	0 Participants n=74 Participants	2 Participants n=267 Participants	5 Participants n=272 Participants
Race/Ethnicity, Customized Race · White	8 Participants n=37 Participants	5 Participants n=37 Participants	6 Participants n=74 Participants	6 Participants n=267 Participants	25 Participants n=272 Participants
Race/Ethnicity, Customized Ethnicity · Hispanic or Latino	1 Participants n=37 Participants	3 Participants n=37 Participants	1 Participants n=74 Participants	2 Participants n=267 Participants	7 Participants n=272 Participants
Race/Ethnicity, Customized Ethnicity · Not Hispanic or Latino	9 Participants n=37 Participants	6 Participants n=37 Participants	9 Participants n=74 Participants	8 Participants n=267 Participants	32 Participants n=272 Participants

PRIMARY outcome

Timeframe: On Study Days 175, 182, 189, 203, 217, 231, 245, 259, 273, and 280.

Population: The number of participants analyzed each week varies due to participants missing that visit.

Proportion of subjects with detectable hookworm eggs, at any time point, in fecal samples, as determined by microscopy using the qualified saline flotation technique

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=9 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=5 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Detectable Hookworm Infection Day 217	4 Participants	3 Participants	4 Participants	1 Participants
Detectable Hookworm Infection Day 231	6 Participants	4 Participants	4 Participants	1 Participants
Detectable Hookworm Infection Day 245	5 Participants	3 Participants	3 Participants	0 Participants
Detectable Hookworm Infection Day 259	4 Participants	2 Participants	4 Participants	0 Participants
Detectable Hookworm Infection Day 273	6 Participants	2 Participants	3 Participants	0 Participants
Detectable Hookworm Infection Day 280	5 Participants	3 Participants	3 Participants	0 Participants
Detectable Hookworm Infection Day 175	0 Participants	0 Participants	0 Participants	0 Participants
Detectable Hookworm Infection Day 182	0 Participants	0 Participants	1 Participants	0 Participants
Detectable Hookworm Infection Day 189	0 Participants	0 Participants	2 Participants	0 Participants
Detectable Hookworm Infection Day 203	3 Participants	4 Participants	2 Participants	1 Participants

PRIMARY outcome

Timeframe: Beginning on Day 0 when the first dose is received and ending on Day 380 (final study visit).

Frequency of study vaccine-related Serious Adverse Events from the time of the first study vaccination through approximately 10 months after the last study vaccination.

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Serious Adverse Events	0 Participants	0 Participants	0 Participants	0 Participants

PRIMARY outcome

Timeframe: Dose 1: Days 0, 3, 7, 14; Dose 2: Days 56, 59, 63, 70; Dose 3: Days 112, 115, 119, 126

Population: 39 participants received the first dose of the study product, 37 participants received the second dose of the study product, and 36 participants received the third and final dose of the study product.

Frequency of solicited injection site and systemic reactogenicity, graded by severity, on the day of each study vaccination through 14 days after each study vaccination.

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Solicited Injection Site and Systemic Reactogenicity Number of Participants Reporting Solicited Adverse Events Post Dose #1	10 Participants	10 Participants	7 Participants	9 Participants
Incidence of Solicited Injection Site and Systemic Reactogenicity Number of Participants Reporting Solicited Adverse Events Post Dose #2	9 Participants	9 Participants	5 Participants	7 Participants
Incidence of Solicited Injection Site and Systemic Reactogenicity Number of Participants Reporting Solicited Adverse Events Post Dose #3	9 Participants	8 Participants	7 Participants	7 Participants

PRIMARY outcome

Timeframe: Day of CHHI, Day 140, and study days: 143, 147, 154, 175, 182, 189, 196, 203, 210, 217, 224, 231, 238, 245, 252, 259, 266, 273, 280. Day 280 is the day of anti-worm treatment.

Population: Number of participants reporting solicited adverse events during CHHI phase of the study.

Frequency of solicited adverse events, graded by severity, on the day of CHHI through study Day 280

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=9 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=5 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Solicited Adverse Events	10 Participants	8 Participants	9 Participants	5 Participants

PRIMARY outcome

Timeframe: Study days: 0, 14, 56, 70, 112, 126, 140, 154, 175, 189, 203, 217, 231, 259, 280.

Population: 39 participants received at least 1 study vaccination and 33 participants received the CHHI.

Frequency of clinical safety laboratory adverse events.

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Clinical Safety Laboratory Abnormalities Number of Participants reporting Clinical Laboratory Adverse Event during Vaccination Phase	0 Participants	1 Participants	2 Participants	3 Participants
Incidence of Clinical Safety Laboratory Abnormalities Number of Participants reporting Clinical Laboratory Adverse Event during CHHI Phase	9 Participants	7 Participants	7 Participants	3 Participants

PRIMARY outcome

Timeframe: From Dose 1 on Day 0 until anti-worm treatment on Day 280.

Population: 39 participants received Dose #1, 37 participants received Dose #2, 36 participants received Dose #3, and 33 participants received the CHHI.

Frequency of unsolicited adverse events, graded by severity, from the time of each study vaccination through approximately 1 month after each study vaccination; and from the time of CHHI through treatment with albendazole (Day 280)

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Unsolicited Adverse Events Participants Reporting Unsolicited AEs up to 28 Days After Dose #2	6 Participants	3 Participants	6 Participants	5 Participants
Incidence of Unsolicited Adverse Events Participants Reporting Unsolicited AEs up to 28 Days After Dose #3	5 Participants	6 Participants	7 Participants	4 Participants
Incidence of Unsolicited Adverse Events Participants Reporting Unsolicited AEs up to 28 Days After Dose #1	4 Participants	5 Participants	8 Participants	6 Participants
Incidence of Unsolicited Adverse Events Participants Reporting Unsolicited AEs post-CHHI	10 Participants	9 Participants	9 Participants	5 Participants

PRIMARY outcome

Timeframe: Entire duration of the study. Beginning Day 0, day of first dose, until Day 380, final study visit.

Frequency of new-onset chronic medical conditions through approximately 10 months after the third study vaccination.

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of New-onset Chronic Medical Conditions	0 Participants	0 Participants	0 Participants	0 Participants

PRIMARY outcome

Timeframe: Entire duration of the study. Beginning Day 0, day of first dose, until Day 380, final study visit.

Frequency of Adverse Events of Special Interest through approximately 10 months after the third study vaccination.

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Incidence of Adverse Events of Special Interest	0 Participants	0 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Week 5 and Week 20 post-CHHI. Study days: 175, 182, 189, 203, 217, 231, 245, 259, 273, and 280.

Population: The number of participants analyzed each week varies due to participants missing that visits and/or that visit occurring too far out of window.

Fecal egg counts as determined by microscopy using the McMaster method, weekly from Weeks 5 through 20 post-CHHI

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=9 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=5 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Fecal Egg Counts Week 5 post-CHHI (Day 175)	0.0 Eggs Standard Deviation 0.0	0.0 Eggs Standard Deviation 0.0	0.0 Eggs Standard Deviation 0.0	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 6 post-CHHI (Day 182)	0.0 Eggs Standard Deviation 0.0	0.0 Eggs Standard Deviation 0.0	4.2 Eggs Standard Deviation 11.8	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 7 post-CHHI (Day 189)	0.0 Eggs Standard Deviation 0.0	0.0 Eggs Standard Deviation 0.0	10.4 Eggs Standard Deviation 23.5	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 9 post-CHHI (Day 203)	5.6 Eggs Standard Deviation 11.8	11.1 Eggs Standard Deviation 16.7	31.0 Eggs Standard Deviation 58.1	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 10 post-CHHI (Day 217)	22.9 Eggs Standard Deviation 41.7	7.4 Eggs Standard Deviation 12.1	38.9 Eggs Standard Deviation 62.9	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 12 post-CHHI (Day 231)	48.3 Eggs Standard Deviation 88.7	14.8 Eggs Standard Deviation 19.4	29.6 Eggs Standard Deviation 58.8	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 14 post-CHHI (Day 245)	35.0 Eggs Standard Deviation 50.0	16.7 Eggs Standard Deviation 34.5	14.6 Eggs Standard Deviation 30.1	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 16 post-CHHI (Day 259)	59.3 Eggs Standard Deviation 89.8	31.5 Eggs Standard Deviation 72.9	31.0 Eggs Standard Deviation 29.5	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 18 post-CHHI (Day 273)	33.3 Eggs Standard Deviation 43.7	16.7 Eggs Standard Deviation 35.6	38.1 Eggs Standard Deviation 48.8	0.0 Eggs Standard Deviation 0.0
Fecal Egg Counts Week 20 post-CHHI (Day 280)	35.4 Eggs Standard Deviation 52.3	13.0 Eggs Standard Deviation 23.2	16.7 Eggs Standard Deviation 23.6	0.0 Eggs Standard Deviation 0.0

SECONDARY outcome

Timeframe: Study days: 14, 70, 126, 140, 175, 189, 231, 280, 320, and 380

Population: The number of participants analyzed each week varies due to participants missing that visits and/or that visit occurring too far out of window. Additionally, 39 participants received Dose 1, 37 participants received Dose 2, 36 participants received Dose 3, and 33 participants received the CHHI.

Anti-Na-GST-1 IgG antibody response as measured in Arbitrary Units per milliliter (AU/mL) of serum, determined by a qualified indirect enzyme-linked immunosorbent assay (ELISA) at approximately 14 days after each vaccination, and approximately 1, 2, 4, 6, 7, 8 and 10 months after the third dose. Levels of IgG antibodies against Na-GST-1 were converted to AUs by homologous interpolation of Optical Density readings at 492nm (OD492) from a standard calibration curve derived from serial dilutions of a human standard reference serum pool collected from high IgG responders (OD492 ≥ 1.000).

Outcome measures

Outcome measures
Measure	Na-GST-1/Alhydrogel + GLA-AF n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel n=10 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 Participants Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 Participants 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
Anti-Na-GST-1 IgG Antibody Response Day 14	1.4 Arbitrary Units (AUs) per milliliter Standard Deviation 0.0	1.7 Arbitrary Units (AUs) per milliliter Standard Deviation 0.9	1.7 Arbitrary Units (AUs) per milliliter Standard Deviation 1.0	1.4 Arbitrary Units (AUs) per milliliter Standard Deviation 0.0
Anti-Na-GST-1 IgG Antibody Response Day 70 (14 days post Dose 2)	26.7 Arbitrary Units (AUs) per milliliter Standard Deviation 65.5	5.6 Arbitrary Units (AUs) per milliliter Standard Deviation 1.1	2.0 Arbitrary Units (AUs) per milliliter Standard Deviation 1.8	34.8 Arbitrary Units (AUs) per milliliter Standard Deviation 30.9
Anti-Na-GST-1 IgG Antibody Response Day 126 (14 days post Dose 3)	18.7 Arbitrary Units (AUs) per milliliter Standard Deviation 23.3	21.1 Arbitrary Units (AUs) per milliliter Standard Deviation 32.4	1.4 Arbitrary Units (AUs) per milliliter Standard Deviation 0.0	55.3 Arbitrary Units (AUs) per milliliter Standard Deviation 65.4
Anti-Na-GST-1 IgG Antibody Response Day 140 (1 month post Dose 3)	10.9 Arbitrary Units (AUs) per milliliter Standard Deviation 12.7	8.5 Arbitrary Units (AUs) per milliliter Standard Deviation 5.1	2.2 Arbitrary Units (AUs) per milliliter Standard Deviation 2.3	31.0 Arbitrary Units (AUs) per milliliter Standard Deviation 29.5
Anti-Na-GST-1 IgG Antibody Response Day 175 (2 months post Dose 3)	7.7 Arbitrary Units (AUs) per milliliter Standard Deviation 7.9	6.9 Arbitrary Units (AUs) per milliliter Standard Deviation 5.2	1.7 Arbitrary Units (AUs) per milliliter Standard Deviation 1.0	42.6 Arbitrary Units (AUs) per milliliter Standard Deviation 72.1
Anti-Na-GST-1 IgG Antibody Response Day 189 (4 months post Dose 3)	6.2 Arbitrary Units (AUs) per milliliter Standard Deviation 6.6	7.1 Arbitrary Units (AUs) per milliliter Standard Deviation 5.8	2.2 Arbitrary Units (AUs) per milliliter Standard Deviation 2.3	26.3 Arbitrary Units (AUs) per milliliter Standard Deviation 28.4
Anti-Na-GST-1 IgG Antibody Response Day 231 (6 months post Dose 3)	5.2 Arbitrary Units (AUs) per milliliter Standard Deviation 5.8	6.3 Arbitrary Units (AUs) per milliliter Standard Deviation 4.4	2.3 Arbitrary Units (AUs) per milliliter Standard Deviation 2.6	35.1 Arbitrary Units (AUs) per milliliter Standard Deviation 53.3
Anti-Na-GST-1 IgG Antibody Response Day 280 (7 months post Dose 3)	4.0 Arbitrary Units (AUs) per milliliter Standard Deviation 3.8	4.5 Arbitrary Units (AUs) per milliliter Standard Deviation 2.9	2.4 Arbitrary Units (AUs) per milliliter Standard Deviation 2.6	21.6 Arbitrary Units (AUs) per milliliter Standard Deviation 26.7
Anti-Na-GST-1 IgG Antibody Response Day 320 (8 months post Dose 3)	3.8 Arbitrary Units (AUs) per milliliter Standard Deviation 3.1	4.6 Arbitrary Units (AUs) per milliliter Standard Deviation 3.0	2.6 Arbitrary Units (AUs) per milliliter Standard Deviation 3.3	22.8 Arbitrary Units (AUs) per milliliter Standard Deviation 35.8
Anti-Na-GST-1 IgG Antibody Response Day 380 (10 months post Dose 3)	3.1 Arbitrary Units (AUs) per milliliter Standard Deviation 3.4	3.9 Arbitrary Units (AUs) per milliliter Standard Deviation 3.4	2.3 Arbitrary Units (AUs) per milliliter Standard Deviation 2.3	110 Arbitrary Units (AUs) per milliliter Standard Deviation 11.6

Adverse Events

Na-GST-1/Alhydrogel

Serious events: 0 serious events

Other events: 10 other events

Deaths: 0 deaths

Na-GST-1/Alhydrogel + CPG 10104

Serious events: 1 serious events

Other events: 9 other events

Deaths: 0 deaths

Na-GST-1/Alhydrogel + GLA-AF

Serious events: 0 serious events

Other events: 10 other events

Deaths: 0 deaths

Saline Placebo

Serious events: 0 serious events

Other events: 10 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Na-GST-1/Alhydrogel n=10 participants at risk 100 µg ˆNaˆ-GST-1/Alhydrogel administered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + CPG 10104 n=9 participants at risk 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 500 µg CPG 10104 delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Na-GST-1/Alhydrogel + GLA-AF n=10 participants at risk 100 µg ˆNaˆ-GST-1/Alhydrogel co-administered with 5 µg GLA-AF delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.	Saline Placebo n=10 participants at risk Sterile saline placebo delivered intramuscularly in the deltoid on study days 0, 56 and 112 followed by controlled human hookworm infection with 50 infectious Necator americanus larvae on study day 140.
General disorders Hospitalization	0.00% 0/10 • For the Vaccination phase, solicited AEs were collected from the day of study vaccination through 14 days after each study vaccination and unsolicited AEs were collected from the day of study vaccination through 28 days after each vaccination. For the CHHI phase, solicited adverse events were collected from day of hookworm larvae administration (day 140) through day 280, the day albendazole treatment and unsolicited AEs were collected from day 140 through day 297. During vaccination phase, solicited adverse events were collected via a participant completed paper symptom diary for 14 days following each vaccination. During CHHI phase, solicited adverse events were collected via a paper participant symptom diary which participants completed daily. The vaccination phase consisted of 39 participants (Group 1: 10, Group 2: 9, Group 3: 10, Group 4: 10) and the CHHI phase consisted of 32 participants (Group 1: 9, Group 2: 5, Group 3: 10, Group 4: 9).	11.1% 1/9 • Number of events 1 • For the Vaccination phase, solicited AEs were collected from the day of study vaccination through 14 days after each study vaccination and unsolicited AEs were collected from the day of study vaccination through 28 days after each vaccination. For the CHHI phase, solicited adverse events were collected from day of hookworm larvae administration (day 140) through day 280, the day albendazole treatment and unsolicited AEs were collected from day 140 through day 297. During vaccination phase, solicited adverse events were collected via a participant completed paper symptom diary for 14 days following each vaccination. During CHHI phase, solicited adverse events were collected via a paper participant symptom diary which participants completed daily. The vaccination phase consisted of 39 participants (Group 1: 10, Group 2: 9, Group 3: 10, Group 4: 10) and the CHHI phase consisted of 32 participants (Group 1: 9, Group 2: 5, Group 3: 10, Group 4: 9).	0.00% 0/10 • For the Vaccination phase, solicited AEs were collected from the day of study vaccination through 14 days after each study vaccination and unsolicited AEs were collected from the day of study vaccination through 28 days after each vaccination. For the CHHI phase, solicited adverse events were collected from day of hookworm larvae administration (day 140) through day 280, the day albendazole treatment and unsolicited AEs were collected from day 140 through day 297. During vaccination phase, solicited adverse events were collected via a participant completed paper symptom diary for 14 days following each vaccination. During CHHI phase, solicited adverse events were collected via a paper participant symptom diary which participants completed daily. The vaccination phase consisted of 39 participants (Group 1: 10, Group 2: 9, Group 3: 10, Group 4: 10) and the CHHI phase consisted of 32 participants (Group 1: 9, Group 2: 5, Group 3: 10, Group 4: 9).	0.00% 0/10 • For the Vaccination phase, solicited AEs were collected from the day of study vaccination through 14 days after each study vaccination and unsolicited AEs were collected from the day of study vaccination through 28 days after each vaccination. For the CHHI phase, solicited adverse events were collected from day of hookworm larvae administration (day 140) through day 280, the day albendazole treatment and unsolicited AEs were collected from day 140 through day 297. During vaccination phase, solicited adverse events were collected via a participant completed paper symptom diary for 14 days following each vaccination. During CHHI phase, solicited adverse events were collected via a paper participant symptom diary which participants completed daily. The vaccination phase consisted of 39 participants (Group 1: 10, Group 2: 9, Group 3: 10, Group 4: 10) and the CHHI phase consisted of 32 participants (Group 1: 9, Group 2: 5, Group 3: 10, Group 4: 9).

Other adverse events

Additional Information

David J. Diemert, MD

George Washington University

Phone: 202-994-2909

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place