Trial Outcomes & Findings for Norovirus Challenge Study (NCT NCT05212168)

NCT ID: NCT05212168

Last Updated: 2025-11-05

Results Overview

Blood samples were collected at different timepoints throughout the study.

• Recruitment status: COMPLETED
• Study phase: PHASE1/PHASE2
• Target enrollment: 165 participants
• Primary outcome timeframe: Day 8
• Results posted on: 2025-11-05

Participant Flow

Participants were enrolled at 1 center in the United States (US) between December 2021 and October 2023.

Healthy participants were randomized in a 1:1 ratio to receive a single oral dose of VXA-G1.1-NN or placebo. The total study duration for each participant was approximately 16 months, including screening, a 28-day vaccination phase, a 28-day Challenge Phase, and up to 365 days of safety follow-up.

Participant milestones

Measure	VXA-G1.1-NN Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the Norwalk virus (NV) genogroup I genotype 1 (GI.1) Norwalk challenge strain, and monitored for signs and symptoms of acute gastroenteritis (AGE) until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Overall Study STARTED	86	79
Overall Study Entered Challenge Phase	76	65
Overall Study COMPLETED	52	42
Overall Study NOT COMPLETED	34	37

Reasons for withdrawal

Measure	VXA-G1.1-NN Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the Norwalk virus (NV) genogroup I genotype 1 (GI.1) Norwalk challenge strain, and monitored for signs and symptoms of acute gastroenteritis (AGE) until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Overall Study Lost to Follow-up	0	3
Overall Study Study terminated by sponsor	30	27
Overall Study Other	4	7

Baseline Characteristics

Norovirus Challenge Study

Baseline characteristics by cohort

Measure	VXA-G1.1-NN n=86 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Total n=165 Participants Total of all reporting groups
Sex: Female, Male Female	43 Participants n=15 Participants	31 Participants n=161 Participants	74 Participants n=100 Participants
Sex: Female, Male Male	43 Participants n=15 Participants	48 Participants n=161 Participants	91 Participants n=100 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	37 Participants n=15 Participants	33 Participants n=161 Participants	70 Participants n=100 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	49 Participants n=15 Participants	46 Participants n=161 Participants	95 Participants n=100 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=15 Participants	0 Participants n=161 Participants	1 Participants n=100 Participants
Race (NIH/OMB) Asian	5 Participants n=15 Participants	8 Participants n=161 Participants	13 Participants n=100 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) Black or African American	21 Participants n=15 Participants	14 Participants n=161 Participants	35 Participants n=100 Participants
Race (NIH/OMB) White	54 Participants n=15 Participants	54 Participants n=161 Participants	108 Participants n=100 Participants
Race (NIH/OMB) More than one race	5 Participants n=15 Participants	3 Participants n=161 Participants	8 Participants n=100 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Age, Continuous	36 years STANDARD_DEVIATION 8 • n=15 Participants	34 years STANDARD_DEVIATION 7 • n=161 Participants	35 years STANDARD_DEVIATION 8 • n=100 Participants

PRIMARY outcome

Timeframe: Up to approximately Day 57

Population: FAP: all randomized participants analyzed by randomized vaccination group assignment, who received study vaccination (active or placebo), and had available data for the specified analysis.

NVG is a composite endpoint defined as meeting both the definition of AGE and NV.

AGE was defined as meeting any one of 3 criteria (diarrhea, vomiting, or diarrhea and vomiting) in any 24-hr rolling period. The individual criteria for diarrhea, vomiting, or diarrhea and vomiting were as follows:

1. Diarrhea: i. ≥ 3 loose or liquid stools in any 24-hr rolling period, or ii. 400 g of loose or liquid stools in any 24-hr rolling period 2. Vomiting: ≥ 2 vomiting episodes in any 24-hr rolling period, or 3. Diarrhea and vomiting: i. one vomiting episode plus any loose or liquid stool in any 24-hr rolling period ii. one vomiting episode plus ≥ 2 of the following events in any 24-hr rolling period:

1. nausea

2. fever (oral temperature ≥ 37.6°C)

3. abdominal cramps or pains

4. abdominal gurgling or bloating

5. myalgia NV infection was defined as having 1 or more positive results in stool or urine by quantitative real time reverse transcription polymerase chain reaction (qRT-PCR).

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Norovirus Gastroenteritis (NVG)	34 Participants	37 Participants

PRIMARY outcome

Timeframe: Day 8

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Blood samples were collected at different timepoints throughout the study.

Outcome measures

Measure	VXA-G1.1-NN n=83 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Levels of Viral Protein 1, Major Capsid, or Surface Protein of Viruses (VP1)-Specific Immunoglobulin A (IgA) Antibody-Secreting Cell (ASC) Against Norwalk at Day 8	79.5 cells/10^6 PBMCs Interval 69.2 to 87.6	0 cells/10^6 PBMCs Interval 0.0 to 4.6

PRIMARY outcome

Timeframe: Day 28

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Blood samples were collected at different timepoints throughout the study. A positive change indicates an increase in titers.

Outcome measures

Measure	VXA-G1.1-NN n=82 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=71 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Geometric Mean Titer (GMT) of Histo-blood Group Antigen (HBGA) Blocking Antibodies Against NV by Blocking Titer 50 (BT50) at Day 28	131.6 Geometric mean titer Interval 101.2 to 171.2	33.2 Geometric mean titer Interval 26.4 to 41.8

PRIMARY outcome

Timeframe: Day 28

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Blood samples were collected at different timepoints throughout the study.

Outcome measures

Measure	VXA-G1.1-NN n=82 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=71 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
VP1-specific Serum Immunoglobulin G (IgG) Response at Day 28	4413573.1 AU/mL Interval 3167431.7 to 6149975.6	700657.0 AU/mL Interval 508361.8 to 965690.5

PRIMARY outcome

Timeframe: Day 28

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Blood samples were collected at different timepoints throughout the study.

Outcome measures

Measure	VXA-G1.1-NN n=82 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=71 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
VP1-specific Serum IgA at Day 28	5555338.7 AU/mL Interval 3713874.2 to 8309863.5	670496.0 AU/mL Interval 450873.7 to 997097.1

SECONDARY outcome

Timeframe: Up to Day 8

Population: Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.

Solicited symptoms of reactogenicity included:

• Gastrointestinal reactions: nausea, vomiting, diarrhea and abdominal pain
• Systemic reactogenicity: malaise/fatigue, anorexia, fever, headache and myalgia

Outcome measures

Measure	VXA-G1.1-NN n=86 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Solicited Symptoms of Reactogenicity	50 Participants	36 Participants

SECONDARY outcome

Timeframe: Up to Day 28 of Vaccination Phase (28-days phase)

Population: Vaccination Phase Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.

Unsolicited AEs referred to any AEs that occurred during a clinical trial but were not specifically pre-defined or actively sought by the study protocol. Unsolicited AEs could include any medical condition or symptom, whether or not it was related to the intervention being studied.

Outcome measures

Measure	VXA-G1.1-NN n=86 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Unsolicited Adverse Events (AEs) During the Vaccination Phase	7 Participants	9 Participants

SECONDARY outcome

Timeframe: Up to approximately 12 months post vaccination

Population: Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.

A SAE was any AE that resulted in one or more of the following outcomes: death, a life-threatening event where the subject was at immediate risk of death (not hypothetically), inpatient hospitalization or the prolongation of existing hospitalization, persistent or significant incapacity or substantial disruption of normal life functions, congenital abnormality or birth defect, or an important medical event that, that jeopardized the participant's health or required medical or surgical intervention to prevent a serious outcome. A NOCI was defined as the diagnosis post-study drug administration of a new medical condition, which was chronic in nature, including those potentially controllable by medication (e.g., diabetes, asthma).

Outcome measures

Measure	VXA-G1.1-NN n=86 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Serious AEs (SAEs), AEs of Specific Interest (AESIs), and New Onsets of Chronic Illness (NOCIs) All SAEs	0 Participants	1 Participants
Number of Participants Who Experienced Serious AEs (SAEs), AEs of Specific Interest (AESIs), and New Onsets of Chronic Illness (NOCIs) All AESI	0 Participants	1 Participants
Number of Participants Who Experienced Serious AEs (SAEs), AEs of Specific Interest (AESIs), and New Onsets of Chronic Illness (NOCIs) All NOCI	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to Day 29 of Challenge Phase (28-days phase)

Population: Challenge Phase Safety Population: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

Unsolicited AEs referred to any AEs that occurred during a clinical trial but were not specifically pre-defined or actively sought by the study protocol. Unsolicited AEs could include any medical condition or symptom, whether or not it was related to the intervention being studied.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Unsolicited AEs During the Challenge Phase	31 Participants	23 Participants

SECONDARY outcome

Timeframe: Day 28 of Challenge Phase (28-days phase)

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

AGE was defined as meeting any one of 3 criteria (diarrhea, vomiting, or diarrhea and vomiting) in any 24-hr rolling period. The individual criteria for diarrhea, vomiting, or diarrhea and vomiting were as follows:

1. Diarrhea: i. ≥ 3 loose or liquid stools produced in any 24-hr rolling period, or ii. 400 g of loose or liquid stools produced in any 24-hr rolling period 2. Vomiting: ≥ 2 vomiting episodes in any 24-hr rolling period, or 3. Diarrhea and vomiting: i. one vomiting episode plus any loose or liquid stool in any 24-hr rolling period ii. one vomiting episode plus ≥ 2 of the following events in any 24-hr rolling period:

1. nausea

2. fever (oral temperature ≥ 37.6°C)

3. abdominal cramps or pains

4. abdominal gurgling or bloating

5. myalgia

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants With AGE During the Inpatient Challenge Phase	40 Participants	39 Participants

SECONDARY outcome

Timeframe: Up to approximately Day 36

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

The Modified Vesikari Scale is a tool used to assess the severity of AGE by evaluating symptoms such as diarrhea, vomiting, fever, and dehydration. It scores these symptoms based on their frequency and severity, with a minimum score of 0 and a maximum score of 20, where higher scores indicate more severe symptoms and lower scores suggest milder or no symptoms and severity.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Severity of AGE Assessed Using the Modified Vesikari Scale	4.2 Score on scale Interval 3.5 to 4.8	4.4 Score on scale Interval 3.8 to 5.1

SECONDARY outcome

Timeframe: Up to approximately Day 57

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

Moderate or severe gastroenteritis was defined by cumulative loose stools ≥ 1000gr during the inpatient period.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Moderate or Severe Gastroenteritis	14 Participants	7 Participants

SECONDARY outcome

Timeframe: Up to approximately Day 57

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received. Only AGE positive participants were included in the analysis

Time to onset of AGE was calculated as the time from challenge administration to the first recorded instance of an event satisfying the criteria for AGE.

AGE was defined as meeting any of the 3 criteria:

1. Diarrhea: i. ≥ 3 loose or liquid stools in any 24-hr rolling period, or ii. 400 g of loose or liquid stools in any 24-hr rolling period 2. Vomiting: ≥ 2 vomiting episodes in any 24-hr rolling period, or 3. Diarrhea and vomiting: i. one vomiting episode plus any loose or liquid stool in any 24-hr rolling period ii. one vomiting episode plus ≥ 2 of the following events in any 24-hr rolling period:

1. nausea

2. fever (oral temperature ≥ 37.6°C)

3. abdominal cramps or pains

4. abdominal gurgling or bloating

5. myalgia

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Duration of AGE	59.0 Hours Interval 26.7 to 117.3	55.8 Hours Interval 28.6 to 107.1

SECONDARY outcome

Timeframe: Up to approximately Day 57

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

Classification of diarrhea was done through grading stools with Grade 3 (thick liquid stool) to Grade 5 (clear water diarrheal stool) being considered diarrhea.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants Who Experienced Incidences of Diarrhea or Emesis Emesis	28 Participants	33 Participants
Number of Participants Who Experienced Incidences of Diarrhea or Emesis Diarrhea	52 Participants	44 Participants

SECONDARY outcome

Timeframe: Challenge Phase Day 8 (equal to Study Day 36)

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received.

NoV infection was defined as a positive qRT-PCR in stool or emesis up to Challenge Period Day 8, and the presence of NV antigen in stool.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Number of Participants With Norovirus (NoV) Infection up to Challenge Period Day 8	44 Participants	53 Participants

SECONDARY outcome

Timeframe: Pre-challenge up to Day 8 of Challenge Phase (equal to Study Day 36)

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received. Only participants with available data at each time point were included.

NoV shedding was assessed by qRT-PCR. Stool samples were reported on 10^3 copies/gm. If a participant produced multiple results for a given study day, the result with the largest shedding response was used for analysis. Samples that were reported as "Not Quantifiable" or as lower than the limit of detection (LOD) were analyzed as ½2*LOD (76.2).

Outcome measures

Measure	VXA-G1.1-NN n=82 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=72 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 2	255.1 10^3 copies/gm Interval 143.9 to 452.1	341.2 10^3 copies/gm Interval 165.6 to 702.7
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 3	6238.9 10^3 copies/gm Interval 2230.9 to 17447.5	15833.5 10^3 copies/gm Interval 5555.2 to 45129.2
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 4	1970.7 10^3 copies/gm Interval 637.9 to 6088.1	16834.9 10^3 copies/gm Interval 4817.1 to 58834.9
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Period Day 5	5412.0 10^3 copies/gm Interval 1150.7 to 25454.6	31096.5 10^3 copies/gm Interval 4975.1 to 194366.0
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 6	1268.7 10^3 copies/gm Interval 0.0 to	4483.0 10^3 copies/gm Interval 0.1 to 207897355.4
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 8	627.3 10^3 copies/gm Interval 340.0 to 1157.1	2737.3 10^3 copies/gm Interval 1400.4 to 5350.3
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Pre-challenge	76.2 10^3 copies/gm The 95% confidence interval was not estimable as all samples were below the LOD.	76.2 10^3 copies/gm The 95% confidence interval was not estimable as all samples were below the LOD.
Geometric Mean Genome Copies (GCs) of NoV Shedding in Stool Measured by qRT-PCR Challenge Phase Day 1	76.2 10^3 copies/gm The 95% confidence interval was not estimable as all samples were below the LOD.	76.2 10^3 copies/gm The 95% confidence interval was not estimable as all samples were below the LOD.

SECONDARY outcome

Timeframe: Pre-challenge up to Day 8 of Challenge Phase (equal to Study Day 36)

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received. Only participants with available data at each time point were included.

NoV shedding was assessed by qRT-PCR. Emesis samples were reported in 10^3 copies/mL. If a participant produced multiple results for a given study day, the result with the largest shedding response was used for analysis. Samples that were reported as "Not Quantifiable" or as lower than the limit of detection (LOD) were analyzed as ½2*LOD (15.3).

Outcome measures

Measure	VXA-G1.1-NN n=25 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=26 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Geometric Mean GCs of NoV Shedding in Emesis Measured by qRT-PCR Challenge Phase Day 3	74.5 10^3 copies/mL Interval 24.9 to 222.7	152.5 10^3 copies/mL Interval 43.9 to 530.3
Geometric Mean GCs of NoV Shedding in Emesis Measured by qRT-PCR Challenge Phase Day 4	15.3 10^3 copies/mL The 95% confidence interval was not estimable as all samples were below the LOD and as only 1 participant was included.	15.3 10^3 copies/mL The 95% confidence interval was not estimable as all samples were below the LOD and as only 1 participant was included.
Geometric Mean GCs of NoV Shedding in Emesis Measured by qRT-PCR Challenge Phase Day 5	15.3 10^3 copies/mL The 95% confidence interval was not estimable as all samples were below the LOD.	15.3 10^3 copies/mL The 95% confidence interval was not estimable as all samples were below the LOD and as only 1 participant was included.
Geometric Mean GCs of NoV Shedding in Emesis Measured by qRT-PCR Challenge Phase Day 2	58.4 10^3 copies/mL Interval 19.8 to 172.4	457.3 10^3 copies/mL Interval 110.2 to 1897.5

SECONDARY outcome

Timeframe: Up to approximately Day 57

Population: Challenge Phase FAP: consisted of all participants who received any study vaccination (active or placebo) and entered the 28-days Challenge Phase. This population was summarized according to the actual vaccination received. Only AGE positive participants were included in the analysis

Duration of NoV Infection was defined as the time from NoV infection to the time of resolution of infection, defined as a negative qRT-PCR result not followed by a positive qRT-PCR result.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Duration of NoV Infection	120.1 Hours Interval 113.4 to 126.4	115.8 Hours Interval 109.5 to 122.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Day 1 (baseline), Day 28 and Day 57

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Fecal samples for immunogenicity assessments were collected on Day 1 (prior to vaccination), Day 28 (1 day prior to challenge), and Day 57 (28 days post-challenge). VP1 GI.1-specific IgA antibody values were normalized by the total IgA in each sample.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
VP1 GI.1-specific Fecal IgA at Day 1, Day 28 and Day 57 Day 1	715.61 μg/mg Interval 442.64 to 1156.92	470.86 μg/mg Interval 316.78 to 699.89
VP1 GI.1-specific Fecal IgA at Day 1, Day 28 and Day 57 Day 28	1888.49 μg/mg Interval 1221.06 to 2920.74	444.31 μg/mg Interval 304.83 to 647.6
VP1 GI.1-specific Fecal IgA at Day 1, Day 28 and Day 57 Day 57	6122.41 μg/mg Interval 3891.96 to 9631.1	5047.07 μg/mg Interval 3000.2 to 8490.39

OTHER_PRE_SPECIFIED outcome

Timeframe: Day 1 (baseline), Day 28 and Day 57

Population: Immunogenicity Population: all randomized participants who received study vaccination (active or placebo), and had available data for the specified analysis.

Saliva samples were collected on Day 1 (prior to vaccination), Day 28 (1 day prior to challenge), and Day 57 (28 days post-challenge). VP1 GI.1-specific IgA antibody values were normalized by the total IgA in each sample.

Outcome measures

Measure	VXA-G1.1-NN n=76 Participants Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=65 Participants Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
VP1 GI.1-specific Saliva IgA at Day 1, Day 28 and Day 57 Day 1	0.40 μg/mg Interval 0.31 to 0.51	0.31 μg/mg Interval 0.27 to 0.35
VP1 GI.1-specific Saliva IgA at Day 1, Day 28 and Day 57 Day 28	1.15 μg/mg Interval 0.84 to 1.57	0.35 μg/mg Interval 0.31 to 0.4
VP1 GI.1-specific Saliva IgA at Day 1, Day 28 and Day 57 Day 57	1.81 μg/mg Interval 1.33 to 2.44	1.84 μg/mg Interval 1.41 to 2.4

Adverse Events

VXA-G1.1-NN

Serious events: 0 serious events

Other events: 55 other events

Deaths: 0 deaths

Placebo

Serious events: 1 serious events

Other events: 47 other events

Deaths: 0 deaths

Serious adverse events

Measure	VXA-G1.1-NN n=86 participants at risk Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 participants at risk Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Vascular disorders Deep vein thrombosis	0.00% 0/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	1.3% 1/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Infections and infestations Cellulitis	0.00% 0/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	1.3% 1/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.

Other adverse events

Measure	VXA-G1.1-NN n=86 participants at risk Healthy participants received a single dose of VXA-G1.1-NN oral vaccine tablet. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.	Placebo n=79 participants at risk Healthy participants received a single dose of matching placebo. Approximately 29 days post-vaccination, participants began the Challenge Phase Day 1. During this phase, participants were isolated, exposed to the NV GI.1 Norwalk challenge strain, and monitored for signs and symptoms of AGE until discharge. Asymptomatic participants were discharged on Day 3 of the Challenge Phase and continued with a series of outpatient visits and telephone follow-ups. Symptomatic participants could remain in isolation for up to an additional 3 days.
Gastrointestinal disorders Abdominal pain	16.3% 14/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	10.1% 8/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Gastrointestinal disorders Diarrhoea	23.3% 20/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	15.2% 12/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Gastrointestinal disorders Nausea	15.1% 13/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	12.7% 10/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
General disorders Malaise	29.1% 25/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	25.3% 20/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Metabolism and nutrition disorders Decreased appetite	11.6% 10/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	10.1% 8/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Musculoskeletal and connective tissue disorders Myalgia	12.8% 11/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	15.2% 12/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.
Nervous system disorders Headache	39.5% 34/86 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.	41.8% 33/79 • Up to approximately 16 months Safety Population: consisted of all participants who received any study vaccination (active or placebo). This population was summarized according to the actual vaccination received.

Additional Information

Maria Apkarian

Vaxart

Phone: +1 (650) 779-4560

Email: mapkarian@vaxart.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place

Restriction type: OTHER