Flu shot just 23 percent effective

Miami (AFP) - This US winter season's flu vaccine has been just 23 percent effective at preventing doctor visits for people of all ages, according to health authorities' early estimates out Thursday.

The flu vaccine for 2014-2015 is not the worst ever -- the past decade has ranged from 10 percent to 60 percent effective -- but its record is worrying enough that the Centers for Disease Control and Prevention have urged doctors to ramp up the use of antiviral medications in people who fall ill with influenza.

Its lack of punch is being blamed on multiple strains of the H3N2 virus that are circulating and making people sick, but that were not included in this season's vaccine.

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