According to the CDC, there was widespread flu activity was visible across all 50 US states by the end of December, a trend not seen once in the 13-year history of the current flu surveillance system. The seasonal flu vaccine, even when not completely preventative, still tends to weaken the severity of a bout of flu. It also saves lives as a 2015 study by the CDC finds that seasonal shots had prevented at least 40,000 deaths from 2005 to 2014.
