New interventions against human norovirus: progress, opportunities, and challenges.

Human norovirus (HuNoV) is the leading causative agent of foodborne disease outbreaks worldwide. HuNoV is highly stable, contagious, and only a few virus particles can cause illness. However, HuNoV is difficult to study because of the lack of an efficient in vitro cell culture system or a small animal model. To date, there is very limited information available about the biology of HuNoV, with most data coming from the study of surrogates, such as HuNoV virus-like particle (VLP), murine norovirus (MNV), and feline calicivirus (FCV). High-risk foods for HuNoV contamination include seafood, fresh produce, and ready-to-eat foods. Currently, there is no effective measure to control HuNoV outbreaks; thus, development of food-processing technologies to inactivate HuNoV in these high-risk foods is urgently needed. Although a VLP-based vaccine induces humoral, mucosal, and cellular immunities in animals and currently is in human clinical trials, development of other new vaccine candidates, such as live vectored vaccines, should be considered. Recent evidence suggests that blockage of virus-receptor interaction may be a promising antiviral target. To enhance our capability to combat this important agent, there is an urgent need to develop multidisciplinary, multi-institutional integrated research and to implement food virology education and extension programs nationwide.