Vaxart, Inc., a privately held, clinical-stage biotechnology company developing oral recombinant vaccines that are administered by tablet rather than by injection, announced positive results demonstrating that the company’s oral norovirus vaccine candidate elicited substantial systemic and mucosal immune responses to norovirus in preclinical studies. The data were presented at the 16th Annual World Vaccine Congress in Madrid, Spain.
“We evaluated our oral vaccine in large and small animal studies, and compared it to an injectable VLP-based vaccine. The oral vaccine induced a robust systemic antibody response equivalent to that of the injectable vaccine, but only the Vaxart oral vaccine induced an intestinal mucosal immune response,” said Sean Tucker, Ph.D., chief scientific officer at Vaxart. “This suggests our oral vaccine may have advantages over injectable approaches, including the ability to neutralize norovirus at the site of infection.”
Norovirus is the leading cause of acute viral gastroenteritis, resulting in diarrhea and vomiting. According to the Centers for Disease Control and Prevention (CDC), norovirus causes an annual estimated 19 to 21 million illnesses and contributes to 56,000 to 71,000 hospitalizations and 570 to 800 deaths in the United States. Worldwide, norovirus causes 20 percent of diarrheal illness and as many as 100,000 deaths each year. Currently, there is no norovirus vaccine on the market.
Vaxart also presented data from a recent Phase 1 human clinical study demonstrating that its H1N1 influenza tablet vaccine generated both neutralizing antibodies as well as a robust mucosal immune response in 92 percent of subjects after a single dose. “Our flu and norovirus vaccines are based on the same delivery platform, so we anticipate that our norovirus vaccine will generate systemic and mucosal immune responses in humans as well,” said Wouter Latour, MD, chief executive officer at Vaxart. “Having both responses may be critical for an effective norovirus vaccine, and really plays to the strength of the Vaxart vaccine, which is administered by tablet. Moreover, this data set further validates the value of the Vaxart platform across multiple indications, including seasonal flu, norovirus and RSV. We are looking forward to evaluating our norovirus tablet vaccine in the clinic in the coming months.”