Norovirus InfectionsPhase 1NCT07254728
A Study to Evaluate Vaxart's Oral Bivalent GI.1/GII.4 Norovirus Vaccine in Healthy Lactating Females and Their Nursing Infants
A Phase 1 study testing VXA-G1.1-NN and VXA-G2.4-NS in people with Norovirus Infections, run by Vaxart at 5 sites in South Africa.
Trial summary
The primary objective of this study is to evaluate the safety and tolerability of an oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female participants and to assess the short-term immunogenicity of oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female… Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Norovirus Infections
- What is being tested?
- VXA-G1.1-NN and VXA-G2.4-NS
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 76 participants
- Where
- 5 sitesSouth Africa
- Study dates
- 27 Oct 2023to 13 Dec 2024
- Phase
- Phase 1
- 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 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Lactating females aged ≥ 18 years at the time of enrolment and their breastfed infants aged >30 days to 11 months of age at the time of the participants' study drug administration.
- In stable and good general health, without significant medical illness, based on medical history, physical examination (including vital signs), and clinical judgment of the investigator.
- Lactating females willing and able to provide informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol.
- Lactating females who are willing to provide consent for their breastfed infant.
- Negative pregnancy tests at screening and prior to dose on Day 1.
- Available for all planned visits and tele-health appointments, and ability to comply with all study-related evaluations (including but not limited to having the ability and willingness to swallow multiple small enteric-coated tablets per study dose, express/pump breastmilk, and collect infant stool samples).
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- Plan to continue breastfeeding as the main source of the infant's nutrition for at least 1 month (longer is preferred with goal of 6 months post dose if possible) from the time of study drug administration. Exclusive breastfeeding is acceptable but not necessary.
- The nursing infant is the product of a singleton pregnancy AND does not have any of the following:
- Any abnormality that may interfere with breastfeeding or milk absorption
- Active infection (may be included if the infection resolves and the participant is re-assessed during the screening period)
- Infant has any other medical condition or abnormality that, in the opinion of the investigator, could compromise the infant's appropriate inclusion in this study including interference with the interpretation of study results (such as malabsorption)
- One or more documented brief resolved unexplained events (BRUEs)
- Extreme prematurity (infants who were born at less than 28 weeks gestation)
- 30 days of age or less at the participant's study drug administration OR greater than 11 months of age at the participant's study drug administration
- Prior hospitalization that is not exclusively for hyperbilirubinemia requiring phototherapy
- Any genetic/metabolic disease
- Any chronic illness requiring long term medication
- Participants must be willing to use a highly effective form of contraception for 30 days prior to vaccination and until 60 days after the vaccination. Acceptable forms are oral, implantable, intrauterine, transdermal, intravaginal, injectable, double barrier or abstinence (participants using diaphragms must also use condom). The form of contraception must be approved by the investigator.
Who cannot join
- Presence of a fever ≥ 38.0°C measured orally at baseline, on Day 1 prior to vaccination. (Assessment may be repeated once during screening period).
- 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).
- Participants who have received antipyretic/analgesic medications within 24 hours prior to the intended vaccine administration.
- Positive human immunodeficiency virus (HIV), Hepatitis B surface antigen (HBsAg), or hepatitis C virus (HCV) tests at the screening visit.
- History of hypersensitivity or allergic reaction to any component of the investigational vaccine, including but not limited to fish gelatin.
- History of serious reactions to vaccination such as anaphylaxis, respiratory problems, hives, or abdominal pain.
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- Presence of significant uncontrolled medical or psychiatric illness (acute or chronic) including the institution of new medical/surgical treatment or significant dose alteration for uncontrolled symptoms or drug toxicity within 3 months of screening and reconfirmed at baseline.
- History of significant pregnancy-related complications during this pregnancy, including but not limited to pre-eclampsia, eclampsia, or gestational diabetes unless a full resolution is documented.
- Cancer, or treatment for cancer, within the 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 or 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:
- Any history of:
- Malignancy
- Malabsorption
- Pancreatobiliary disorders
- Inflammatory bowel disease
- Irritable bowel disease
- Hiatal hernia
- Surgical resection
- History of diagnosis or treatment in past 5 years of:
- Esophageal or gastric motility disorder
- Gastroesophageal reflux disease (GERD) - Will allow for participants with a history of pregnancy-related GERD if fully resolved for >3 months and no other history of GERD diagnosis
- Peptic ulcer
- Cholecystectomy
- Any condition that resulted in the absence or removal of the spleen.
- History of any form of angioedema.
- Diagnosed bleeding disorder or significant bruising or bleeding difficulties that could make blood draws problematic.
- History of GI bleeding including hematochezia (blood in stool) or melena (black stool).
- Any significant hospitalization within the last year which in the opinion of the investigator or sponsor could interfere with study participation.
- Any of the following history or conditions that may lead to a 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 the risk of thrombosis within 6 months prior to screening:
- Recent surgery other than fully healed cesarean delivery or excision/ biopsy of cutaneous lesions
- Immobility (confined to bed or wheelchair for 3 or more successive days)
- Head trauma with loss of consciousness or documented brain injury
- Receipt of anticoagulants for prophylaxis of thrombosis
- Recent clinically significant infection including hospitalization for COVID-19 related illness
- Any other condition that, in the clinical judgment of the investigator, would jeopardize the safety or rights of a participant taking in the study, would render the participant unable to comply with the protocol, or would interfere with the evaluation of the study endpoints.
- Receipt of a licensed vaccine (including any COVID-19 vaccines under Emergency Use Authorization) within 14 days prior to study drug dose or planned administration during the study active period.
- 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.
- Use of medications known to affect the immune function (including but not limited to systemic corticosteroids, leukotriene modifiers, and Janus kinase [JAK] inhibitors) within 2 weeks before study drug administration or planned use during the active study period.
- Daily use of nonsteroidal anti-inflammatory drugs within 7 days prior to study drug administration or planned use during the active study period.
- Donation or receipt of blood or blood products within 30 days prior to study drug administration or planned donation during the active study period.
- Participating in any clinical trial with another investigational product within 30 days prior to the first trial visit or intend to participate in another clinical trial at any time during the conduct of this trial.
- Are first-degree relatives of individuals involved in trial conduct.
- Positive urine drug screen for drugs of abuse at screening.
- Positive alcohol test at screening or baseline.
- History of drug, alcohol, or chemical abuse within 1 year of screening.
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
South Africa5 sites
WITS RHI Research Centre
Hillbrow, 2001
Progress Clinical Research Unit
Honeydew, 2040
Newtown Clinical Research Centre
Johannesburg, 2001
Trident Clinical
Kimberley, 8301
FCRN Clinical Trials Centre (Pty) Ltd
Vereeniging, 1935
About this study
Official title: A Phase I, Multicenter, Randomized, Double-blind, Placebo-controlled Single Dose, Dose-ranging Study to Evaluate the Safety, Tolerability, and Immunogenicity of Orally Administered Bivalent GI.1/GII.4 Norovirus Vaccine in Healthy Lactating Females ≥ 18 Years Old and Their Breast-feeding Infants
The primary objective of this study is to evaluate the safety and tolerability of an oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female participants and to assess the short-term immunogenicity of oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female participants and its association with the immunogenicity response in breastmilk.
- Conditions
- Norovirus Infections
- Being tested
- VXA-G1.1-NN, VXA-G2.4-NS, Placebo Tablets
- Keywords
- Healthy participants, VXA-G1.1-NN, VXA-G2.4-NS
- Medical subject headings
- Caliciviridae Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VXA-G1.1-NNBiological
Also called GI.1
Oral tablets.
VXA-G2.4-NSBiological
Also called GII.4
Oral tablets.
Placebo TabletsBiological
Oral tablets.
| Study group | Role | What they receive |
|---|---|---|
| Bivalent GII.4/GI.1 Medium Dose Vaccine | Experimental | Participants will receive a medium dose of bivalent VXA-G1.1-NN and VXA-GII.4-NS as an oral tablet on Day 1. Receives: Biological: VXA-G1.1-NN; Biological: VXA-G2.4-NS |
| Bivalent GII.4/GI.1 High Dose Vaccine | Experimental | Participants will receive a high dose of bivalent VXA-G1.1-NN and VXA-GII.4-NS as an oral tablet on Day 1. Receives: Biological: VXA-G1.1-NN; Biological: VXA-G2.4-NS |
| Placebo | Placebo comparator | Participants will receive matching placebo orally on Day 1. Receives: Biological: Placebo Tablets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants (Mothers) With Any Solicited Symptoms of Reactogenicity for 1 Week Following Trial Dose
Solicited symptoms of reactogenicity were predefined adverse events (AEs) for which the participant was specifically questioned, and which were noted by the participant in their solicited symptom diary, including: fever (any temperature 100°F or higher), headache, myalgia (muscle pain), abdominal pain, anorexia (defined as not eating), nausea, vomiting, diarrhea, and malaise/fatigue. The severity of each solicited symptom of reactogenicity was graded by the participant as mild, moderate, severe or life-threatening.
Measured: 1 week post study dose (8 days)
Number of Participants (Mothers) With Unsolicited Treatment-emergent Adverse Events (TEAEs)
TEAEs:AEs that began after start of an investigational product or an already present event that worsens in intensity or frequency following intervention.An AE considered serious (SAE) if,in view of Investigator or Sponsor,it resulted in death,life-threatening AE,inpatient hospitalization/prolongation of hospitalization,persistent or significant incapacity or disability disrupting normal life functions,congenital anomaly/birth defect,or an important medical event which based upon medical judgment may have jeopardized participant and required intervention to prevent 1 of outcomes.AESIs:serious/non-serious AEs of scientific and medical concern with potential immune mediated conditions and events associated with thrombosis and thrombocytopenia.NOCI:diagnosis post-enrollment and vaccination of new chronic medical condition,including those controllable by medication.An AE was unsolicited if it did not fulfill conditions prelisted in eCRF in terms of diagnosis/onset window post-vaccination.
Measured: 4 weeks post dose (29 days)
Geometric Mean Concentration (GMC) of Serum Viral Protein 1 (VP1) Specific (G1.1) Immunoglobulin A (IgA) on Days 1, 8 and 29
GMC of serum VP1 specific (G1.1) IgA was measured by Meso Scale Discovery (MSD) assay. Assay was measured in an arbitrary unit per milliliter (AU/mL).
Measured: Days 1, 8 and 29
GMC of Serum VP1 Specific (G2.4) IgA on Days 1, 8 and 29
GMC of serum VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in AU/mL.
Measured: Days 1, 8 and 29
Geometric Mean Fold Rise (GMFR) From Day 1 to Day 8 of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 8
GMFR of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 29
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 8
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 29
Number of Participants Who Achieved a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G1.1) IgA
A 2, 3, 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29 and 180
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G2.4) IgA
A 2, 3, 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29 and 180
GMC of Breastmilk VP1 Specific (G1.1) IgA on Days 1, 8 and 29
GMC of breastmilk VP1 specific (G1.1) IgA was measured by MSD assay. Assay is measured in Relative Light Unit per microgram (RLU)/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
Measured: Days 1, 8, and 29
GMC of Breastmilk VP1 Specific (G2.4) IgA on Days 1, 8 and 29
GMC of breastmilk VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in RLU/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
Measured: Days 1, 8 and 29
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 8
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 8
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 29
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 29
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Breastmilk VP1 Specific (G1.1) IgA
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibody compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, 60 and 180
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Breastmilk VP1 Specific (G2.4) IgA
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, 60 and 180
Secondary outcomes (23)
Number of Participants With SAEs, AESIs and NOCIs Through 12 Months Post Dose
An unsolicited AE was an observed AE that did not fulfill the conditions prelisted in the eCRF in terms of diagnosis and/or onset window post-vaccination. An AESIs serious or nonserious) is one of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and rapid communication by the Investigator to the Sponsor can be appropriate. NOCIs was defined as diagnosis post-enrollment and vaccination of a new medical condition, which is chronic in nature, including those potentially controllable by medication. Only unsolicited SAEs, AESI and NOCIs data was planned to be collected and assessed for the assessment of this OM and solicited SAEs, AESIs and NOCIs was out of the scope of assessment. Participants with unsolicited SAEs, AESIs and NOCIs throughout the trial were reported in this outcome measure.
Measured: Up to 12 months
GMC of Serum VP1 Specific (G1.1) IgA on Day 180
GMC of serum VP1 specific (G1.1) IgA was measured by MSD assay. Assay is measured in AU/mL.
Measured: Day 180
GMC of Serum VP1 Specific (G2.4) IgA on Day 180
GMC of serum VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in AU/mL.
Measured: Day 180
GMFR of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 180
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 180
GMC of Breastmilk VP1 Specific (G1.1) IgA on Days 60 and 180
GMC of breastmilkVP1 specific (G1.1) IgA was measured by MSD assay. Assay is measured in RLU/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
Measured: Days 60 and 180
GMC of Breastmilk VP1 Specific (G2.4) IgA on Days 60 and 180
GMC of breastmilk VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in RLU/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
Measured: Days 60 and 180
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 60
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 60 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 60
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 60
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 60 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 60
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 180
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Day 180
GMC of Serum VP1 Specific (G1.1) Immunoglobulin G (IgG) on Days 1, 8, 29, and 180
GMC of serum VP1 specific (G1.1) IgG was measured by MSD assay. Assay is measured in AU/mL.
Measured: Days 1, 8, 29, and 180
GMC of Serum VP1 Specific (G2.4) IgG on Days 1, 8, 29, and 180
GMC of serum VP1 specific (G2.4) IgG was measured by MSD assay. Assay is measured in AU/mL.
Measured: Days 1, 8, 29 and 180
GMFR of Serum VP1 Specific (G1.1) IgG From Day 1 to Days 8, 29, and 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).
Measured: From Day 1 to Days 8, 29, and 180
GMFR of Serum VP1 Specific (G2.4) IgG From Day 1 to Days 8, 29, and 180
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).
Measured: From Day 1 to Days 8, 29, and 180
Number of Participants Who Achieved a 2-fold, 3-fold, and 4-fold GMC Rise in Serum VP1 Specific (G1.1) IgG
A 2, 3, and 4-fold rise represents the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, and 180
Number of Participants Who Achieved a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G2.4) IgG
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, and 180
Geometric Mean Titer (GMT) of Serum Blocking Titers 50 (BT50) (G1.1) on Days 1, 8, 29, and 180
Serum BT50 (G1.1) through 6 months after trial drug dose was measured by histo-blood group antigen (HBGA) assay. Blood samples were collected at different timepoints throughout the trial.
Measured: Days 1, 8, 29, and 180
GMT of Serum BT50 (G2.4) on Days 1, 8, 29, and 180
Serum BT50 (G2.4) through 6 months after trial drug dose was measured by HBGA assay. Blood samples were collected at different timepoints throughout the trial.
Measured: Days 1, 8, 29, and 180
GMFR of Serum BT50 (G1.1) From Day 1 to Days 8, 29 and 180
The fold rise was calculated per participant by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Days 8, 29, and 180
GMFR of Serum BT50 (G2.4) From Day 1 to Days 8, 29 and 180
The fold rise was calculated per participant by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).
Measured: Day 1 to Days 8, 29 and 180
Number of Participants Who Achieved 2-fold, 3-fold, and 4-fold GMT Rise in Serum VP1 Specific (G1.1) IgG
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, and 180
Number of Participants With 2-fold, 3-fold and 4-fold GMT Rise in Serum VP1 Specific IgG (G2.4)
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Measured: Days 1, 8, 29, and 180
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Nov 2025
- Study start27 Oct 2023
- Primary completion13 Dec 2024
- Study completion13 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Norovirus InfectionsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 76 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vaxart
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Vaxart, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07254728
- Sponsor's protocol ID
- VXA-NVV-108
- Status last verified
- Mar 2026
- First submitted
- 19 Nov 2025
- Last updated
- 15 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I, Multicenter, Randomized, Double-blind, Placebo-controlled Single Dose, Dose-ranging Study to Evaluate the Safety, Tolerability, and Immunogenicity of Orally Administered Bivalent GI.1/GII.4 Norovirus Vaccine in Healthy Lactating Females ≥ 18 Years Old and Their Breast-feeding Infants
- ClinicalTrials.gov ID
- NCT07254728
- Acronym / sponsor ID
- VXA-NVV-108
- Conditions
- Norovirus Infections
- Keywords
- Healthy participants, VXA-G1.1-NN, VXA-G2.4-NS
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 76 participants (actual)
- Lead sponsor
- VaxartIndustry (pharma, biotech, devices)
- Study start
- 27 Oct 2023 (actual)
- Primary completion
- 13 Dec 2024 (actual)
- Study completion
- 13 Dec 2024 (actual)
- First posted
- 28 Nov 2025 (actual)
- Results
- Posted 15 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of this study is to evaluate the safety and tolerability of an oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female participants and to assess the short-term immunogenicity of oral bivalent GI.1/GII.4 norovirus vaccine administration in healthy lactating female participants and its association with the immunogenicity response in breastmilk.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Bivalent GII.4/GI.1 Medium Dose Vaccine | Experimental | Biological: VXA-G1.1-NN, Biological: VXA-G2.4-NSParticipants will receive a medium dose of bivalent VXA-G1.1-NN and VXA-GII.4-NS as an oral tablet on Day 1. |
| Bivalent GII.4/GI.1 High Dose Vaccine | Experimental | Biological: VXA-G1.1-NN, Biological: VXA-G2.4-NSParticipants will receive a high dose of bivalent VXA-G1.1-NN and VXA-GII.4-NS as an oral tablet on Day 1. |
| Placebo | Placebo comparator | Biological: Placebo TabletsParticipants will receive matching placebo orally on Day 1. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (18 listed)
- Lactating females aged ≥ 18 years at the time of enrolment and their breastfed infants aged >30 days to 11 months of age at the time of the participants' study drug administration.
- In stable and good general health, without significant medical illness, based on medical history, physical examination (including vital signs), and clinical judgment of the investigator.
- Lactating females willing and able to provide informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol.
- Lactating females who are willing to provide consent for their breastfed infant.
- Negative pregnancy tests at screening and prior to dose on Day 1.
Key exclusion criteria (50 listed)
- Presence of a fever ≥ 38.0°C measured orally at baseline, on Day 1 prior to vaccination. (Assessment may be repeated once during screening period).
- 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).
- Participants who have received antipyretic/analgesic medications within 24 hours prior to the intended vaccine administration.
- Positive human immunodeficiency virus (HIV), Hepatitis B surface antigen (HBsAg), or hepatitis C virus (HCV) tests at the screening visit.
- History of hypersensitivity or allergic reaction to any component of the investigational vaccine, including but not limited to fish gelatin.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| VXA-G1.1-NNAlso: GI.1Oral tablets. | Biological | Bivalent GII.4/GI.1 High Dose Vaccine, Bivalent GII.4/GI.1 Medium Dose Vaccine |
| VXA-G2.4-NSAlso: GII.4Oral tablets. | Biological | Bivalent GII.4/GI.1 High Dose Vaccine, Bivalent GII.4/GI.1 Medium Dose Vaccine |
| Placebo TabletsOral tablets. | Biological | Placebo |
Primary outcome
Number of Participants (Mothers) With Any Solicited Symptoms of Reactogenicity for 1 Week Following Trial Dose
Time frame: 1 week post study dose (8 days)
Solicited symptoms of reactogenicity were predefined adverse events (AEs) for which the participant was specifically questioned, and which were noted by the participant in their solicited symptom diary, including: fever (any temperature 100°F or higher), headache, myalgia (muscle pain), abdominal pain, anorexia (defined as not eating), nausea, vomiting, diarrhea, and malaise/fatigue. The severity of each solicited symptom of reactogenicity was graded by the participant as mild, moderate, severe or life-threatening.
Number of Participants (Mothers) With Unsolicited Treatment-emergent Adverse Events (TEAEs)
Time frame: 4 weeks post dose (29 days)
TEAEs:AEs that began after start of an investigational product or an already present event that worsens in intensity or frequency following intervention.An AE considered serious (SAE) if,in view of Investigator or Sponsor,it resulted in death,life-threatening AE,inpatient hospitalization/prolongation of hospitalization,persistent or significant incapacity or disability disrupting normal life functions,congenital anomaly/birth defect,or an important medical event which based upon medical judgment may have jeopardized participant and required intervention to prevent 1 of outcomes.AESIs:serious/non-serious AEs of scientific and medical concern with potential immune mediated conditions and events associated with thrombosis and thrombocytopenia.NOCI:diagnosis post-enrollment and vaccination of new chronic medical condition,including those controllable by medication.An AE was unsolicited if it did not fulfill conditions prelisted in eCRF in terms of diagnosis/onset window post-vaccination.
Geometric Mean Concentration (GMC) of Serum Viral Protein 1 (VP1) Specific (G1.1) Immunoglobulin A (IgA) on Days 1, 8 and 29
Time frame: Days 1, 8 and 29
GMC of serum VP1 specific (G1.1) IgA was measured by Meso Scale Discovery (MSD) assay. Assay was measured in an arbitrary unit per milliliter (AU/mL).
GMC of Serum VP1 Specific (G2.4) IgA on Days 1, 8 and 29
Time frame: Days 1, 8 and 29
GMC of serum VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in AU/mL.
Geometric Mean Fold Rise (GMFR) From Day 1 to Day 8 of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 8
Time frame: Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
GMFR of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 29
Time frame: Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 8
Time frame: Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 29
Time frame: Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Number of Participants Who Achieved a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G1.1) IgA
Time frame: Days 1, 8, 29 and 180
A 2, 3, 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G2.4) IgA
Time frame: Days 1, 8, 29 and 180
A 2, 3, 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
GMC of Breastmilk VP1 Specific (G1.1) IgA on Days 1, 8 and 29
Time frame: Days 1, 8, and 29
GMC of breastmilk VP1 specific (G1.1) IgA was measured by MSD assay. Assay is measured in Relative Light Unit per microgram (RLU)/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
GMC of Breastmilk VP1 Specific (G2.4) IgA on Days 1, 8 and 29
Time frame: Days 1, 8 and 29
GMC of breastmilk VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in RLU/µg of total IgA which is a normalized measure used to quantify the specific binding of IgA antibodies to norovirus VLPs (measured in RLU) relative to the total amount of IgA protein present in a breast milk.
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 8
Time frame: Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 8
Time frame: Day 1 to Day 8
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 8 with least square mean value at baseline (Day 1).
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 29
Time frame: Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 29
Time frame: Day 1 to Day 29
GMFR was measured by MSD assay. The fold rise was calculated per participant by dividing the least square mean value on Day 29 with least square mean value at baseline (Day 1).
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Breastmilk VP1 Specific (G1.1) IgA
Time frame: Days 1, 8, 29, 60 and 180
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibody compared to pre-vaccination dosing Baseline (Day 1).
Number of Participants Who Achieve a 2-fold, 3-fold and 4-fold GMC Rise in Breastmilk VP1 Specific (G2.4) IgA
Time frame: Days 1, 8, 29, 60 and 180
A 2, 3, and 4-fold rise represented the participants with at least a 2, 3, or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).
23 secondary outcomes
Number of Participants With SAEs, AESIs and NOCIs Through 12 Months Post Dose
Time frame: Up to 12 months
GMC of Serum VP1 Specific (G1.1) IgA on Day 180
Time frame: Day 180
GMC of Serum VP1 Specific (G2.4) IgA on Day 180
Time frame: Day 180
GMFR of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 180
Time frame: Day 1 to Day 180
GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 180
Time frame: Day 1 to Day 180
GMC of Breastmilk VP1 Specific (G1.1) IgA on Days 60 and 180
Time frame: Days 60 and 180
GMC of Breastmilk VP1 Specific (G2.4) IgA on Days 60 and 180
Time frame: Days 60 and 180
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 60
Time frame: Day 1 to Day 60
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 60
Time frame: Day 1 to Day 60
GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 180
Time frame: Day 1 to Day 180
GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 180
Time frame: Day 1 to Day 180
GMC of Serum VP1 Specific (G1.1) Immunoglobulin G (IgG) on Days 1, 8, 29, and 180
Time frame: Days 1, 8, 29, and 180
GMC of Serum VP1 Specific (G2.4) IgG on Days 1, 8, 29, and 180
Time frame: Days 1, 8, 29 and 180
GMFR of Serum VP1 Specific (G1.1) IgG From Day 1 to Days 8, 29, and 180
Time frame: From Day 1 to Days 8, 29, and 180
GMFR of Serum VP1 Specific (G2.4) IgG From Day 1 to Days 8, 29, and 180
Time frame: From Day 1 to Days 8, 29, and 180
Number of Participants Who Achieved a 2-fold, 3-fold, and 4-fold GMC Rise in Serum VP1 Specific (G1.1) IgG
Time frame: Days 1, 8, 29, and 180
Number of Participants Who Achieved a 2-fold, 3-fold and 4-fold GMC Rise in Serum VP1 Specific (G2.4) IgG
Time frame: Days 1, 8, 29, and 180
Geometric Mean Titer (GMT) of Serum Blocking Titers 50 (BT50) (G1.1) on Days 1, 8, 29, and 180
Time frame: Days 1, 8, 29, and 180
GMT of Serum BT50 (G2.4) on Days 1, 8, 29, and 180
Time frame: Days 1, 8, 29, and 180
GMFR of Serum BT50 (G1.1) From Day 1 to Days 8, 29 and 180
Time frame: Day 1 to Days 8, 29, and 180
GMFR of Serum BT50 (G2.4) From Day 1 to Days 8, 29 and 180
Time frame: Day 1 to Days 8, 29 and 180
Number of Participants Who Achieved 2-fold, 3-fold, and 4-fold GMT Rise in Serum VP1 Specific (G1.1) IgG
Time frame: Days 1, 8, 29, and 180
Number of Participants With 2-fold, 3-fold and 4-fold GMT Rise in Serum VP1 Specific IgG (G2.4)
Time frame: Days 1, 8, 29, and 180
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director study director
Vaxart, Inc.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing VXA-G1.1-NN and VXA-G2.4-NS in people with Norovirus Infections, run by Vaxart at 5 sites in South Africa.
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 18 inclusion and 50 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 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in South Africa. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 2026). 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 (Mothers) With Any Solicited Symptoms of Reactogenicity for 1 Week Following Trial Dose (time frame: 1 week post study dose (8 days)). The study lists 18 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 2026.