Why Is This Year’s Flu Vaccine Less Effective?

Flu Vaccine

Did you get a flu vaccine for this year? It may not be as helpful as you hoped for.

A new study, published in the online journal Morbidity and Mortality Weekly Report, found that getting a flu shot cut one’s risk of getting the flu by just 48% this season. The H3N2 component of the 2016-2017 flu vaccine only offered 43% protection against influenza, compared to 73% protection for those who received the straight influenza B component of the vaccine.

“Forty percent to 50 percent is a lot better than zero, but what it really begs the question is: Why are we not working hard to get new and better flu vaccines?” said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy, to Stat News. “Last year we spent over a billion dollars researching new HIV vaccines — an amount that I think is an important investment. But the best estimate we can come up with is we only spend about $35 million globally on … research on new game-changing flu vaccines.’’

Similar findings have also been recorded elsewhere this year. European scientists reported 38% vaccine effectiveness for H3N2, while Canadian researchers reported 42% protection for it.

Jacqueline Katz, deputy director of the CDC’s influenza division, believes the poor performance of the H3N2 component of the vaccine directly correlates to the way flu vaccine is produced in hen’s eggs.