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Completed

NCT Number: NCT07254728

A Study to Evaluate Vaxart's Oral Bivalent GI.1/GII.4 Norovirus Vaccine in Healthy Lactating Females and Their Nursing 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.

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Key information

Conditions

Norovirus Infections Caliciviridae Infections Infections RNA Virus Infections Virus Diseases

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Phase 1

Primary location

WITS RHI Research Centre, Hillbrow, South Africa

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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).
  • 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.

Exclusion criteria

  • 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.
  • 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:

a. Any history of:

i. 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. 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

iii. Peptic ulcer

iv. 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:

i. Recent surgery other than fully healed cesarean delivery or excision/ 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 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.

Treatment and study plan

VXA-G1.1-NN

Biological

Oral tablets.

Other names: GI.1

VXA-G2.4-NS

Biological

Oral tablets.

Other names: GII.4

Placebo Tablets

Biological

Oral tablets.

Primary outcomes

  1. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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).

  6. 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).

  7. 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).

  8. 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).

  9. 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).

  10. 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).

  11. 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.

  12. 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.

  13. 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).

  14. 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).

  15. 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).

  16. 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).

  17. 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).

  18. 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).

Secondary outcomes

  1. Number of Participants With SAEs, AESIs and NOCIs Through 12 Months Post Dose

    Time frame: Up to 12 months

    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.

  2. GMC of Serum VP1 Specific (G1.1) IgA on Day 180

    Time frame: Day 180

    GMC of serum VP1 specific (G1.1) IgA was measured by MSD assay. Assay is measured in AU/mL.

  3. GMC of Serum VP1 Specific (G2.4) IgA on Day 180

    Time frame: Day 180

    GMC of serum VP1 specific (G2.4) IgA was measured by MSD assay. Assay is measured in AU/mL.

  4. GMFR of Serum VP1 Specific (G1.1) IgA From Day 1 to Day 180

    Time frame: 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).

  5. GMFR of Serum VP1 Specific (G2.4) IgA From Day 1 to Day 180

    Time frame: 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).

  6. GMC of Breastmilk VP1 Specific (G1.1) IgA on Days 60 and 180

    Time frame: 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.

  7. GMC of Breastmilk VP1 Specific (G2.4) IgA on Days 60 and 180

    Time frame: 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.

  8. GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 60

    Time frame: 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).

  9. GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 60

    Time frame: 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).

  10. GMFR of Breastmilk VP1 Specific (G1.1) IgA From Day 1 to Day 180

    Time frame: 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).

  11. GMFR of Breastmilk VP1 Specific (G2.4) IgA From Day 1 to Day 180

    Time frame: 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).

  12. 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 (G1.1) IgG was measured by MSD assay. Assay is measured in AU/mL.

  13. GMC of Serum VP1 Specific (G2.4) IgG on Days 1, 8, 29, and 180

    Time frame: 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.

  14. 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 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).

  15. 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

    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).

  16. 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

    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).

  17. 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

    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).

  18. 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

    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.

  19. GMT of Serum BT50 (G2.4) on Days 1, 8, 29, and 180

    Time frame: 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.

  20. 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

    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).

  21. 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

    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).

  22. 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

    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. 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

    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).

Other outcomes

  1. GMC of Nasal VP1 Specific (G1.1) IgA

    Time frame: Days 1, 8, 29, 60, and 180

    GMC of nasal VP1 specific (G1.1) IgA from lactating mothers was measured by MSD assay. Assay is measured in microgram per milligram (µg/mg).

  2. GMC of Nasal VP1 Specific (G2.4) IgA

    Time frame: Days 1, 8, 29, 60, and 180

    GMC of nasal VP1 specific (G2.4) IgA from lactating mothers was measured by MSD assay. Assay is measured in µg/mg.

  3. GMFR of Nasal VP1 Specific (GI.I) IgA From Day 1 to Days 8, 29, 60 and 180

    Time frame: Day 1 to Days 8, 29, 60 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).

  4. GMFR of Nasal VP1 Specific (G2.4) IgA From Day 1 to Days 8, 29, 60 and 180

    Time frame: Day 1 to Days 8, 29, 60 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).

  5. Number of Participants With 2-fold, 3-fold and 4-fold GMC Rise in Nasal VP1 Specific IgA (G1.1)

    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).

  6. Number of Participants With 2-fold, 3-fold and 4-fold GMC Rise in Nasal VP1 Specific IgA (G2.4)

    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).

  7. GMC of Saliva VP1 Specific (G1.1) IgA

    Time frame: Days 1, 8, 29, 60, and 180

    GMC of saliva VP1 specific (G1.1) IgA from lactating mothers was measured by MSD assay. Assay is measured in µg/mg.

  8. GMC of Saliva VP1 Specific (G2.4) IgA

    Time frame: Days 1, 8, 29, 60, and 180

    GMC of saliva VP1 specific (G2.4) IgA from lactating mothers was measured by MSD assay. Assay is measured in µg/mg.

  9. GMFR of Saliva VP1 Specific (G1.1) IgA From Day 1 to Days 8, 29, 60 and 180

    Time frame: Day 1 to Days 8, 29, 60, 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).

  10. GMFR of Saliva VP1 Specific (G2.4) IgA From Day 1 to Days 8, 29, 60, and 180

    Time frame: From Day 1 to Days 8, 29, 60, 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).

  11. Number of Participants With 2-fold, 3-fold and 4-fold GMC Rise in Saliva VP1 Specific IgA (G1.1)

    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).

  12. Number of Participants With 2-fold, 3-fold and 4-fold GMC Rise in Saliva VP1 Specific IgA (G2.4)

    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).

  13. GMC of Infant Stool VP1 Specific (G1.1) IgA

    Time frame: Days 1, 29 and 60

    GMC of infant stool VP1 specific (G1.1) IgA was measured by Enzyme-linked immunosorbent assay (ELISA). Assay is measured in mg/gm.

  14. GMC of Infant Stool VP1 Specific (G2.4) IgA

    Time frame: Days 1, 29 and 60

    GMC of infant stool VP1 specific (G2.4) IgA was measured by ELISA. Assay is measured in mg/gm.

  15. GMFR of Infant Stool VP1 Specific (G1.1) IgA From Day 1 to Days 29 and 60

    Time frame: Day 1 to Days 29 and 60

    GMFR was measured by ELISA. The fold rise was calculated per participant (infant) by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).

  16. GMFR of Infant Stool VP1 Specific (G2.4) IgA From Day 1 to Days 29 and 60

    Time frame: Day 1 to Days 29 and 60

    GMFR was measured by ELISA. The fold rise was calculated per infant (participant) by dividing the least square mean value on Days 8, 29 and 180 with least square mean value at baseline (Day 1).

  17. Number of Infants With 2-fold, 3-fold and 4-fold GMC Rise in Infant Stool VP1 Specific IgA (G1.1)

    Time frame: Days 1, 29 and 60

    A 2, 3 and 4-fold rise represented the participants (infants) with at least a 2, 3 or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).

  18. Number of Infants With 2-fold, 3-fold and 4-fold GMC Rise in Infant Stool VP1 Specific IgA (G2.4)

    Time frame: Days 1, 8, 29 and 60

    A 2, 3 and 4-fold rise represented the participants (infants) with at least a 2, 3 or 4-fold rise in antibodies compared to pre-vaccination dosing Baseline (Day 1).

  19. Number of Participants With Norovirus Acute Gastroenteritis

    Time frame: From first dose up to Day 365

    Data was not collected for this outcome measure.

Sponsors and collaborators

Lead sponsor

Vaxart

Industry

Registry information

Official study 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

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Nov 28, 2025
Registry last updated
Apr 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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