Flu Season

FILE - Assemblyman Al Muratsuchi, D-Torrance, reacts as he receives a flu shot from Tyler Poncy, a licensed vocational nurse during a free flu vaccine clinic at the Capitol in Sacramento, Calif. Health officials say the worst of the flu season appears to be over.  (AP Photo/Rich Pedroncelli)

AP/Rich Pedroncelli

By LAURAN NEERGAARD, AP Medical Writer

WASHINGTON (AP) — It's flu shot time, and health officials are bracing for a potentially miserable fall and winter.

The clues: The Southern Hemisphere, especially Australia, was hit hard over the past few months with a flu strain that's notorious for causing severe illness, especially in seniors.

And in the U.S., small clusters of that so-called H3N2 flu already are popping up.

Dr. William Schaffner of Vanderbilt University and the National Foundation for Infectious Diseases calls that flu strain "the bad actor."

Dr, Daniel Jernigan of the U.S. Centers for Disease Control and Prevention says there's a chance the flu season in the U.S. could be similar to Australia's, but health officials can't say for sure.

Health officials are urging people to get vaccinated.