Outbreaks of norovirus in health care settings and outbreaks caused by a particular genotype of the virus are more likely to make people seriously ill, according to a new study in The Journal of Infectious Diseases. Based on an analysis of nearly 3,800 U.S. outbreaks from 2009 to 2016, the research confirms several factors that can make norovirus outbreaks more severe and may help guide efforts to develop a vaccine to prevent this highly contagious disease.
Source: https://medicalxpress.com/news/2018-11-norovirus-outbreaks-efforts-vaccine.htmlCan you explain in simple way?? Sorry but I didn't understood properly.