Norovirus cases in the US have more than doubled compared to last season's peak. The highly contagious virus causes acute gastroenteritis, leading to symptoms like diarrhea, vomiting, nausea, and stomach pain.

Hand sanitizer alone isn't enough to protect you from norovirus, experts say. So it's important to know how to stay safe and wash your hands properly. The FDA announced on Wednesday that it has banned the use of Red No. 3, an additive used to give food and drinks a cherry-red color.