Norovirus, a highly contagious virus that infects the stomach and intestines, may soon have a vaccine pill available to reduce the risk of infection. In a recent trial where individuals were intentionally exposed to the virus, promising results were observed.
The virus, which causes symptoms like vomiting and diarrhea that usually resolve within a few days, poses a significant economic burden due to lost workdays and hospitalizations globally. Sarah Caddy, from Cornell University in New York, highlights the importance of finding a solution to this problem.
Sean Tucker and his team at Vaxart, a biotech company in San Francisco, developed an oral vaccine that increases levels of IgA antibodies. These antibodies can prevent norovirus from entering cells, indicating the potential for infection prevention.
During the trial involving 141 participants aged 18 to 49, half of them took the vaccine pill while the others received a placebo. Subsequently, all participants were exposed to a high dose of the GI.1 strain of norovirus. The results showed that 82% of the placebo group became infected, compared to only 57% of the vaccinated group.
According to Caddy, reducing the risk of infection by around 25 percentage points and avoiding severe symptoms would likely motivate individuals to take the vaccine. Additionally, vaccinated participants showed lower levels of virus shedding in their stool and vomit, suggesting a potential decrease in virus transmission.
The vaccine works by boosting levels of protective IgA antibodies in various bodily fluids. However, the duration of protection and the vaccine’s efficacy in different age groups still require further investigation.
Tucker’s team is also exploring the development of a vaccine that can protect against multiple strains of norovirus. If successful, the GI.1 vaccine could be available within the next two to three years.
Overall, the potential for a norovirus vaccine pill offers hope for reducing the impact of this contagious virus and improving public health outcomes.
