Nationwide, we’re on track for a nasty flu season, with both a large number of cases and many severe ones that require hospitalizations, according to the Centers for Disease Control and Prevention. It declared an influenza epidemic this week, a status achieved at some point nearly every year, though not usually this early in the season. FAQ 
 
 
 
 Explore flu trends - United States We've found that certain search terms are good indicators of flu activity. On top of that, about half of the viruses the CDC had been finding were drift variants from what this year's vaccine covers, potentially reducing its effectiveness. She said her pediatrician friends had posted on Facebook “that they are tired, and can’t wait for the flu to go away.” 
 
 “They are busy, and they are overbooked,” she said. CBS News chief medical correspondent Dr. Jon LaPook said that because of this mismatch, the current flu vaccine will probably be about a third less effective than normal.
– Brace yourself: All signs point to a particularly bad flu season, reports the Upshot blog at the New York Times. For one thing, the CDC says the nation has reached the epidemic stage, and while that designation usually arrives every year, it's earlier than normal. The Verge notes that we didn't hit epidemic level until mid-January in the last two flu seasons. Also not helping: The number of people getting flu shots is lower than normal, and the vaccine itself is a worse match than usual for this year's strain. The mismatch means that the shot is about one-third less effective than normal, reports CBS News. “We’re already above the peak that we saw last year, and we’re increasing,” says a flu expert at the CDC, who predicts that this season's peak probably won't arrive for weeks. The agency says 22 states are now reporting high levels of the flu, up from 13 last week. Google Flu Trends reports much the same. One last piece of the puzzle: This year's most prevalent strain is H3N2, and H3 viruses in general tend to be the most dangerous, reports the Weather Channel.