This season's flu vaccine is only 16 percent effective at preventing infection, according to new estimates from the CDC.
Historically, flu shot efficacy rates have ranged from a high of 60 percent in the 2010-11 season to a low of 10 percent for the 2004-05 season, when the CDC started tracking this data.
The vaccine's low efficacy rate this season "suggests that there was a mismatch between the strains of virus in the vaccine and what's circulating," Jesse Goodman, MD, a former chief scientist at the FDA who was not involved with the report, told The New York Times.
Despite the apparent mismatch, the CDC still recommends all Americans 6 months and older get vaccinated against the flu annually, as it can prevent serious virus-related complications.
The U.S. flu season runs from October to March. This season, flu activity declined in December and January amid the omicron surge and increased in early February. The CDC estimates that, so far this season, there have been at least 2.7 million flu illnesses, 26,000 hospitalizations and 1,500 related deaths.
The CDC's report, published March 11, is based on data from 3,636 people across seven states.