A clinical trial has shown that an experimental norovirus vaccine given as a pill elicits defensive responses in older adults, who are most vulnerable to this stomach bug. The results, published in Science Translational Medicine, provide another step towards combating the highly infectious virus.
Norovirus is a robust and extremely contagious virus that spreads through the fecal-oral route. Infected individuals shed billions of virus particles in their vomit and diarrhea, which can linger on surfaces for up to two weeks. Exposure to just 10 virus particles can trigger an infection.
The Centers for Disease Control and Prevention estimates that norovirus causes between 19 and 21 million cases of acute gastroenteritis in the US each year, resulting in 109,000 hospitalizations and 900 deaths. The economic burden is estimated at $2 billion to $10.6 billion.
To combat this virus, researchers have aimed to design a vaccine effective for older adults, who are more susceptible due to weakened immune responses. However, norovirus poses specific challenges, including limited laboratory models and animal systems for testing candidate drugs.
The new experimental vaccine has shown promise in eliciting defensive responses in older adults. With the virus having 49 different genotypes, it’s unclear if protection against one genotype or group will provide overall immunity. Further research is needed to determine the effectiveness of this vaccine and develop a solution to combat this highly infectious and devastating virus.
Source: https://arstechnica.com/health/2025/03/saliva-that-fights-norovirus-experimental-oral-vaccine-is-nothing-to-spit-at