In this article, Norovirus is spreading rapidly across the U.S. this winter, and Moderna is working on developing a vaccine for it. A large phase three trial of the vaccine is currently ongoing, with results expected later this year or in 2026. Moderna is waiting to reach a certain number of cases to analyze the data and assess the vaccine’s effectiveness, causing the timeline to be uncertain. Doran Fink, Moderna’s clinical therapeutic area head for gastrointestinal and bacterial pathogens, mentioned that the 25,000-person study is enrolling participants ahead of schedule, possibly due to the increased norovirus cases this season.
Norovirus is a highly contagious stomach bug that leads to symptoms like vomiting and diarrhea. It spreads easily in places like nursing homes, daycares, and cruise ships, and is more common during the winter months. This winter has seen a significant increase in norovirus cases, with twice as many positive tests in January compared to last year, according to the Centers for Disease Control and Prevention. Norovirus outbreaks have risen by 36% so far this season as of Dec. 11.
Currently, there is no vaccine available for norovirus due to its various types, which pose a challenge for immunization. Moderna’s vaccine candidate targets the three genotypes responsible for most infections. It works by training the immune system to recognize and fight off norovirus-like particles without causing an infection. The vaccine candidate does not cover the genotype causing the majority of this year’s infections, but the study aims to determine if it can protect against other norovirus types.
Moderna’s objective is not to completely prevent norovirus infections, as the symptoms appear rapidly after exposure. Instead, the goal is to reduce the severity of symptoms and prevent the need for medical intervention. The company aims to focus on vaccinating vulnerable populations like seniors, who are at higher risk of complications from norovirus. Additionally, healthcare workers, daycare staff, teachers, and cruise ship passengers are potential target groups for the vaccine.
Investors are questioning the commercial viability of Moderna’s vaccine, especially in protecting individuals in nursing homes or on cruises. The company is not currently testing the vaccine in children but would consider it if the vaccine proves effective in adults.
