First human trials show efficacy of oral norovirus vaccine

Two recent studies from US universities have demonstrated the effectiveness of an experimental vaccine in inducing a robust and long-lasting antibody response against several norovirus strains, the major cause of outbreaks of acute gastroenteritis worldwide. According to the WHO, norovirus infections cause 700 million cases of gastroenteritis each year, 200,000 of which are fatal. There is currently no vaccine against the pathogen, which has many strains that quickly evade the immune system. However, a vaccine may soon be available. The first oral vaccine pill tested, called VX22, has been shown to produce antibodies capable of neutralising several strains of norovirus, including those responsible for major outbreaks. This vaccine was tested by a US research group led by scientists from the University of Texas at Austin, the University of North Carolina at Chapel Hill, and the National Institutes of Health (NIH). The second experimental tablet vaccine, VXA-G1.1-NN, was designed to target a different norovirus genotype and has been shown to induce a robust and durable (more than 200 days) antibody and T-cell response against this pathogen. The drug was tested at the University of Maryland in adults aged 55 to 80. Professor George Georgiou, co-author of the study published in Science Translational Medicine, underscored that a vaccine could provide lasting protection against the effects of norovirus, as well as a potential treatment for those already infected.