Norovirus Vaccine Candidate for Lactating Mothers Delivers Protective Antibodies

Although there is no approved vaccine to prevent norovirus, it is estimated that approximately 21 million people in the United States are infected with this virus every year, including about 15% of children under the age of 5.

While pediatric deaths resulting from norovirus are rare in the U.S., they are more common in developing countries.

Nevertheless, the economic burden of norovirus in the United States alone is estimated to be $10.6 billion annually.

A recently completed Phase I trial, partially funded by the Bill & Melinda Gates Foundation, included immunogenicity measures.

On April 30, 2024, Vaxart, Inc. announced that it had completed the topline analysis evaluating the Company's orally administered bivalent GI.1/GII.4 norovirus vaccine candidate.

The VXA-NVV-108 clinical trial focused on vaccinating lactating mothers.

Antibodies to norovirus rose on average four-fold for the G1.1 virus strain and six-fold for the GII.4 virus strain in the breast milk of lactating mothers who received the Vaxart vaccine candidate in the high dose group.

Furthermore, there were no vaccine-related serious adverse events, no dose-limiting pharmacotoxicity, and no new onset of chronic illness was observed through the active period.

"This is an important step forward as we drive toward a vaccine candidate that may make it possible for mothers to protect their children against this highly contagious – and potentially lethal – virus."

"It can be difficult to immunize the youngest children mucosally because the immune system is still developing."

"Passive transfer of antibodies from mothers to infants via breast milk is an innovative approach to potentially improve infection resistance in infants," said Dr. James F. Cummings, Vaxart's Chief Medical Officer, in a press release.

As of late April 2024, the World Health Organization has not pre-qualified any norovirus vaccine candidate.