AzTrials
AzTrials

Norovirus InfectionsPhase 2NCT05626803

A Study to Determine the Safety and Immunogenicity of Bivalent GI.1 and GII.4 Vaccines in Healthy Volunteers

A Phase 2 study testing Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose, Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose and Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose in people with Norovirus Infections, run by Vaxart at 3 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This study is designed to evaluate the safety and immunogenicity of two monovalent Norovirus (NoV) oral tableted vaccine candidates, VXA-G1.1-NN and VXA-GII.4-NS co-administered (bivalent delivery) against a matching placebo arm. Read more about this study

Who is it for?
Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for
Norovirus Infections
What is being tested?
Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose, Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose and Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
135 participants
Where
3 sitesUnited States
Study dates
26 Jan 2023to 16 Oct 2023
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • To be eligible for this study, subjects must meet all the following:
  • In stable and good general health, without significant medical illness, based on medical history, physical examination, and vital signs at screening based on investigator judgement.
  • Body mass index (BMI) between >/= 17.0 and </= 35.0 kg/m2 at screening SNG.
  • Available for all planned visits and tele-health appointment, and willing to complete all protocol-defined procedures and assessments (including ability and willingness to swallow multiple small enteric-coated tablets per study dose).
  • Female subjects must not be breastfeeding and must provide a negative pregnancy test at screening and pre-dose.
  • Female subjects must fulfill one of the following criteria:
Show all 10Show fewer
  • At least 1 year post-menopausal (defined as amenorrhea for greater than or equal to 12 consecutive months prior to screening without alternative medical cause) or surgically sterile.
  • Female subjects of childbearing potential must be willing to use a highly effective form of contraception for 30 days prior to initial vaccination and until 60 days after last vaccination. Acceptable forms are oral, implantable, intrauterine, transdermal, intravaginal, injectable, double barrier or abstinence (subjects using diaphragms must also use condom). The form of contraception must be approved by the investigator.
  • Male subjects must agree to practice abstinence from heterosexual intercourse or to use an effective method of birth control as noted above from first vaccination to 60 days after last vaccination. Male subjects must agree to refrain from donating sperm and practice abstinence from all intercourse or to use an effective method of double barrier birth control or condom as noted above from first vaccination to 60 days after last vaccination.
  • Capable of understanding and giving signed informed consent which includes compliance with the requirements and restrictions listed in the ICF and in the protocol.

Who cannot join

  • The subjects must be excluded from participating in the study if they meet any of the following:
  • Known clotting/bleeding issues and/or personal and family history with increased risk of bleeding or clotting.
  • Presence of significant uncontrolled medical or psychiatric illness (acute or chronic) including institution of new medical/surgical treatment or significant dose alteration for uncontrolled symptoms or drug toxicity within 3 months prior to screening and reconfirmed at baseline.
  • Cancer, or treatment for cancer or any procedure or preventive medication for cancer or to prevent recurrence, within past 3 years (excluding fully treated and resolved basal cell carcinoma or squamous cell carcinoma)
  • Presence of immunosuppression or medical condition possibly associated with impaired immune responsiveness, including diabetes mellitus- type 1 and 2
  • History of irritable bowel disease or other inflammatory digestive or gastrointestinal condition that could affect the distribution/safety evaluation of an orally administered vaccine targeting the mucosa of the small intestine. Such conditions may include but are not limited to:
Show all 34Show fewer
  • Any history of: i. GI malignancy ii. malabsorption iii. pancreatobiliary disorders iv. inflammatory bowel disease v. irritable bowel disease vi. hiatal hernia vii. surgical resection b. History of diagnosis or treatment in past 5 years of: i. esophageal or gastric motility disorder ii. gastro esophageal reflux disorder iii. peptic ulcer iv. cholecystectomy
  • History of any form of angioedema
  • History of serious reactions to vaccination such as anaphylaxis, respiratory problems, hives or abdominal pain
  • Diagnosed bleeding disorder or significant bruising or bleeding difficulties that could make blood draws problematic.
  • Any condition that resulted in the absence or removal of the spleen
  • Acute disease within 72 hours prior to vaccination defined as the presence of a moderate or severe illness (as determined by the investigator through medical history and physical exam). (Assessment may be repeated once during Screening Period)
  • Presence of a fever greater than or equal to 38°C measured orally at baseline.
  • Any significant hospitalization within the last year which in the opinion of the investigator or sponsor could interfere with study participation.
  • Any history or conditions that may lead to higher risk of clotting events and/or thrombocytopenia:
  • Family or personal history of bleeding or thrombosis.
  • History of heparin-related thrombotic events, and/or receiving heparin treatments.
  • History of autoimmune or inflammatory disease.
  • Presence of any of the following conditions known to increase risk of thrombosis within 6 months prior to screening:
  • Recent surgery other than removal/biopsy of cutaneous lesions ii. Immobility (confined to bed or wheelchair for 3 or more successive days) iii. Head trauma with loss of consciousness or documented brain injury iv. Receipt of anticoagulants for prophylaxis of thrombosis v. Recent clinically significant infection, including hospitalization for COVID-19 infection.
  • Any other condition that in the clinical judgement of the investigator would jeopardize the safety or rights of a subject taking the study drug, would render the subject unable to comply within the protocol or would interfere with the evaluation of the study endpoints diagnostic assessments.
  • Positive human immunodeficiency virus (HIV), Hepatitis B surface antigen (HBsAg) or Hepatitis C virus (HCV) tests at the screening visit.
  • History of GI bleeding including hematochezia (blood in stool) or melena (black stool)
  • Positive urine drug screen for drugs of abuse at screening (positive test for marijuana is not exclusionary; however concurrent use of marijuana during the study Active period through Day 29 is prohibited).
  • Positive breath or urine alcohol test at screening and baseline.
  • Receipt of a licensed vaccine (including any COVID-19 vaccines under emergency use authorization) within 14 days prior to baseline vaccination or planned administration during the study active period (Day 29).
  • Use of antibiotics, proton pump inhibitors, H2 blockers or antacids within 7 days prior to study drug administration or planned use during the active study period (Day 29).
  • Use of medications known to affect the immune function (e.g., including but not limited to systemic corticosteroids, leukotriene modifiers, and JAK inhibitors) within 2 weeks before study drug administration or planned use during the active study period (Day 29).
  • Daily use of nonsteroidal anti-inflammatory drugs within 7 days prior to study drug administration or planned use during the active study period (Day 29). Low dose daily ASA less than or equal to 100 mg for cardio-protection is not exclusionary.
  • Administration of any investigational vaccine, drug or device within 8 weeks preceding study drug administration, or planned use within the duration of the study
  • Previous participation in a Vaxart Clinical Trial or other NoV vaccine trial unless confirmed receipt of placebo.
  • Donation or use of blood or blood products within 30 days prior to study drug administration or planned donation during the active study period (Day 29).
  • History of drug, alcohol, or chemical abuse within 1 year of screening.
  • History of hypersensitivity or allergic reaction to any component of the investigational vaccine, including but not limited to fish gelatin allergy.

Trial locations and contacts

3 sites in 1 country.

United States3 sites
  • Johnson County Clin-Trials

    Lenexa, Kansas, 66219

  • Ark Clinical Research

    Long Beach, California, 90806

  • Nucleus Network Pty Ltd

    Saint Paul, Minnesota, 55114

Other trials in United States

About this study

Official title: A Phase 2, Multicenter, Randomized, Double-blind, Placebo-controlled, Single Dose, Dose-ranging Study to Determine the Safety and Immunogenicity of Bivalent GI.1 and GII.4 Vaccine Administered Orally to Healthy Volunteers Aged Greater Than or Equal to 18 Years and Less Than or Equal to 80 Years Old.

This study is designed to evaluate the safety and immunogenicity of two monovalent Norovirus (NoV) oral tableted vaccine candidates, VXA-G1.1-NN and VXA-GII.4-NS co-administered (bivalent delivery) against a matching placebo arm. Bivalent GI.1 and GII.4 vaccines are being investigated for the prevention of noroviral gastroenteritis caused by norovirus GI.1 and GII.4.

Read the detailed description

Norovirus infections are a leading cause of sporadic and epidemic gastroenteritis across all age groups worldwide. This study is designed as a standard double-blind placebo-controlled single administration, dose ranging study to evaluate the safety and immunogenicity of 2 different doses of VXA-GII.4-NS plus VXA-G1.1-NN (high and medium dose administered orally for the prevention of Norovirus infection), compared with a placebo.

This study will enroll a total of 135 subjects with10 sentinel subjects in an open label period (dosing staggered to not-more-than 2 subjects per 24 hours) and randomize 125 subjects in three arms.

The first 10 sentinel subjects will receive the open label high dose of active vaccine. If no dose-related toxicities are observed, and upon the recommendation of the SMC following review of safety data, subjects will be randomized in a 2:2:1 ratio to one of the 3 study arms to receive active vaccine or placebo. After vaccination on Day 1, the study will include an Active Study Period that runs through 4 weeks after administration (Day 29), and a Follow-up Period of one year for safety and duration of immune response.

Being tested
Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose, Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose, Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose, Placebo
Medical subject headings
Caliciviridae Infections

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/doseDrug

    The first 10 sentinel subjects will receive open label high dose of active vaccine. Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets; total dose is 2×10 to the power 11 IU/dose

  • Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/doseDrug

    50 subjects will receive high dose of active vaccine. Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets; total dose is 2×10 to the power 11 IU/dose

  • Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/doseDrug

    50 subjects will receive Bivalent GII.4/GI.1 medium dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 5×10 to the power 10 tablets; total dose is 1×10 to the power 11 IU/dose

  • PlaceboDrug

    25 subjects will receive matching placebo

Study groups in NCT05626803
Study groupRoleWhat they receive
Open Label SentinelExperimentalBivalent GII.4/GI.1 vaccine Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets total dose is 2×10 to the power 11 IU/dose (sentinel n=10)
Receives: Drug: Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose
Medium Dose ArmExperimentalBivalent GII.4/GI.1 vaccine Bivalent GII.4/GI.1 medium dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 5×10 to the power 10 tablets total dose is 1×10 to the power 11 IU/dose (N=50)
Receives: Drug: Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose
High Dose ArmExperimentalBivalent GII.4/GI.1 vaccine Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets total dose is 2×10 to the power 11 IU/dose (N=50)
Receives: Drug: Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose
Placebo ArmPlacebo comparatorPlacebo tablets (N= 25)
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants With Solicited Symptoms of Reactogenicity (Gastrointestinal [GI] and Systemic)

    Solicited adverse events (AEs) are predefined signs and symptoms of reactogenicity for which the participants were specifically questioned, and which were noted by the participant in their Solicited Symptom Diary for 7 days after drug administration, including:

    • fever (any temperature 100.4°F or higher)
    • headache
    • myalgia (muscle pain)
    • abdominal pain
    • anorexia (defined as not eating)
    • nausea
    • vomiting
    • diarrhoea
    • malaise/fatigue.

    The severity of each solicited symptoms of reactogenicity was graded by the participant as mild, moderate, severe or life-threatening. Participants with multiple Solicited AEs were only counted once in summarizing overall percentages of Solicited AEs, the highest severity of which was used.

    Measured: Up to Day 8

  2. Number of Participants With Unsolicited AEs

    Treatment emergent AEs (TEAEs) are defined as AEs that occurred following the first administration of study medication. An unsolicited AE is an observed AE that did not fulfill the conditions prelisted in terms of diagnosis and/or onset window post-vaccination.

    The severity of each AE was graded by the participant as mild, moderate or severe/ life-threatening.

    Measured: Up to Day 29

  3. Serum - Anti-Vaccine Protein 1 (VP1) GI.1 Immunoglobulin A (IgA) Levels by Meso Scale Discovery (MSD) Assay

    Serum levels of Anti-VP1 GI.1 IgA were evaluated using cellular and humoral immune (HI) function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method. Assay is measured in AU/mL.

    Measured: Day 1 and Day 29

  4. Fold Rise in Serum - Anti-VP1 GI.1 IgA Levels by MSD Assay

    Serum levels of Anti-VP1 GI.1 IgA were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1). 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  5. Serum - Anti-VP1 GII.4 IgGA Levels by MSD Assay

    Serum levels of Anti-VP1 GII.4 IgA were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method. Assay is measured in AU/mL.

    Measured: Day 1 and Day 29

  6. Fold Rise in Serum - Anti-VP1 GII.4 IgA Levels by MSD Assay

    Serum levels of Anti-VP1 GII.4 IgA were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1). 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  7. Serum - Anti-VP1 GI.1 Immunoglobulin G (IgG) Levels by MSD Assay

    Serum levels of Anti-VP1 GI.1 IgG were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method. Assay is measured in AU/mL.

    Measured: Day 1 and Day 29

  8. Fold Rise in Serum - Anti-VP1 GI.1 IgG Levels by MSD Assay

    Serum levels of Anti-VP1 GI.1 IgG were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1). 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  9. Serum - Anti-VP1 GII.4 IgG Levels by MSD Assay

    Serum levels of Anti-VP1 GII.4 IgG were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method. Assay is measured in AU/mL.

    Measured: Day 1 and Day 29

  10. Fold Rise in Serum - Anti-VP1 GII.4 IgG Levels by MSD Assay

    Serum levels of Anti-VP1 GII.4 IgG were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1). 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  11. Serum - Anti-VP1 GI.1 Blocking Antibodies (BT50) Titers by MSD Assay

    Serum levels of Anti-VP1 GI.1 BT50 were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  12. Fold Rise in Serum - Anti-VP1 GI.1 BT50 Titers by MSD Assay

    Serum levels of Anti-VP1 GI.1 BT50 were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1).

    Measured: Day 1 and Day 29

  13. Serum - Anti-VP1 GII.4 BT50 Titers by MSD Assay

    Serum levels of Anti-VP1 GII.4 BT50 were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

  14. Fold Rise in Serum - Anti-VP1 GII.4 BT50 Titers by MSD Assay

    Serum levels of Anti-VP1 GII.4 BT50 were evaluated using cellular and HI function assays from blood and mucosal (saliva and nasal swab) samples. The fold rise was calculated per participant by dividing the antibody concentration (original scale) on Day 29 with antibody concentration at baseline (Day 1). 95% confidence intervals were estimated by Clopper-Pearson exact method.

    Measured: Day 1 and Day 29

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Nov 2022
  2. Study start26 Jan 2023
  3. Primary completion16 Oct 2023
  4. Study completion16 Oct 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
135 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05626803
Sponsor's protocol ID
VXA-NVV-202
Status last verified
Apr 2025
First submitted
15 Nov 2022
Last updated
15 Apr 2025
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose, Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose and Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose in people with Norovirus Infections, run by Vaxart at 3 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 34 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 15 Apr 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Solicited Symptoms of Reactogenicity (Gastrointestinal [GI] and Systemic) (time frame: Up to Day 8). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2025.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in