US flu season arrives early, driven by an unexpected virus

FILE - In this Feb. 7, 2018 file photo, a nurse prepares a flu shot at the Salvation Army in Atlanta. The U.S. winter flu season is off to its earliest start in more than 15 years. An early barrage of illness in the South has begun to spread more broadly, and there’s a decent chance flu season could peak much earlier than normal, health officials say. (AP Photo/David Goldman)

NEW YORK — The U.S. winter flu season is off to its earliest start in more than 15 years.