Norovirus, also known as the stomach bug, is spreading across the U.S. Here's what to know about the contagious virus and how best to prevent an infection.

There’s currently no approved vaccine for norovirus, although Moderna has begun a phase three trial in the U.S. for a vaccine using mRNA technology and aims to test it in 25,000 adults worldwide. Norovirus causes about 200,000 deaths worldwide each year.

It's no secret that winter is a time when illness is prominent. Coughs, colds, and viruses are seemingly running rampant this time of year. This is thanks to the drier air and an influx of time spent indoors,