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Wits RHI

VAXART Study

Infectious Diseases
Vaccine Preventable Diseases

VAXART Study: 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 Breastfeeding Infants.

Rationale

Noroviruses (NoVs) are a diverse group of small, nonenveloped, single-stranded RNA viruses that cause acute gastroenteritis. While NoVs can affect all age groups, infants aged 6 to 23 months bear the highest burden of NoV disease. Following the global adoption of the rotavirus vaccine, NoV infections have emerged as a leading cause of diarrheal disease in infants. It is estimated that NoVs contribute to 64,000 hospitalization cases, 900,000 clinic visits, and up to 200,000 fatalities in children under five years in developing countries annually. This underscores the urgent need for interventions to prevent the spread of this contagious disease.

Vaxart’s oral NoV vaccine employs a novel non-replicating adenoviral-based platform, previously demonstrated to be well tolerated and safe in over 600 healthy adults. Collaborative research has shown that immunizing lactating ferrets with the Vaxart vaccine resulted in induced immunogenicity in breastmilk. It is hypothesized that the passive transfer of antibodies through breastmilk could help inhibit diarrheal diseases in breastfeeding infants. This study will evaluate the immunogenic effect of the orally administered NoV vaccine in the breastmilk of lactating females and fecal samples from their infants.

Primary Objectives

  • Safety: To determine the safety and tolerability of the oral bivalent dosing regimen of GI.1 and GII.4 norovirus vaccine in healthy lactating female participants.
  • Immunogenicity: To assess the short-term immunogenicity of the oral bivalent GI.1/GII.4 norovirus vaccine in healthy lactating females, particularly the association with vaccine-specific antibody responses in breastmilk.

Secondary Objectives

  • Safety: To evaluate the long-term safety of the bivalent GI.1/GII.4 norovirus vaccine for up to 12 months after the last vaccination.
  • Immunogenicity: To assess the immunogenicity of the oral bivalent GI.1/GII.4 norovirus vaccine in healthy lactating females and its association with immunogenicity responses in breastmilk.

Investigators

Wits RHI

  • Prof Thesla Palanee-Phillips, Co-Principal Investigator
  • Dr Nkosiphile Ndlovu, Co-Investigator

Media Coverage

  1. Vaxart Press Release, 30 April 2024: Vaxart Announces Positive Results for Its Bivalent Norovirus Vaccine Candidate in Lactating Mothers

Latest Update

April 2024

For more details about VAXART Study please email rhicomms@wrhi.ac.za

Click here for further details regarding the VAXART study.

Research Brief

VAXART Study