CDC: Flu vaccine only 23 percent effective this season

ATLANTA, Jan. 15 (UPI) -- It looks like the U.S. Centers for Disease Control's prediction in December that this year's flu vaccine would be less effective was accurate.

The CDC's weekly Morbidity and Mortality report to be published Friday found this season's vaccine reduced a person's risk of needing to be treated by the doctor for the flu by 23 percent.

That's down from 51 percent effectiveness in the 2013-14 season. Over the past 10 years, the effectiveness rate of the flu vaccine has ranged from 10 percent and 21 percent at its lowest in the 2004-05 and 2005-06 seasons, to 56 percent and 60 percent in the 2009-10 and 2010-11 seasons.

"Physicians should be aware that all hospitalized patients and all outpatients at high risk for serious complications should be treated as soon as possible with one of three available influenza antiviral medications if influenza is suspected, regardless of a patient's vaccination status and without waiting for confirmatory testing," says Joe Bresee, branch chief in CDC's Influenza Division. "Health care providers should advise patients at high risk to call promptly if they get symptoms of influenza."

In December, the CDC warned this year's predominant flu strain, H3N2, is a particularly bad one, and to make matters worse, the strain drifted or varied slightly since the flu vaccine was created. The CDC said 70 percent of H3N2 viruses have drifted from the one covered by the vaccine.

"This likely accounts for the reduced vaccine effectiveness," a release by the CDC said.