CDC: Flu vaccines just 25% effective against worst strain this year

Medical experts warn about new flu strain emerging

Was Getting the Flu Shot Worthwhile? Vaccine Only 25 Percent Effective Against the Most Common Strain

"These results confirm my earlier concerns that public health messaging this year was too focused on the low efficacy of the vaccine in preventing flu infection, rather than preventing flu deaths", he told MedPage Today. Dr. Pechon says she's encountered patients who believe the flu shot can give you the flu.

It's only 25 percent effective against the most common strain circulating this year, the H3N2 strain, CDC's Dr. Alicia Fry and colleagues found. And it was 42 percent effective against Type B flu viruses.

The flu shot's overall effectiveness against all strains was pegged at 36 percent, the CDC said.

"For this season, only 20 percent [of children who died from the flu] have been vaccinated, and half of these children were otherwise healthy", he said. In general, viruses in the influenza B family cause less serious illness than those in the A group. Studies in those two countries showed the vaccine only prevented 10 percent or 17 percent of H3N2 cases.

Scott Hensley, an associate professor of microbiology at the University of Pennsylvania who studies flu vaccines, said this year's vaccine is about as effective against H3N2 as last year's was, but it's still valuable to get the shot.


There's only been one other time in the last decade when the flu vaccine did a worse job.

That's the highest number since the Minnesota Department of Health began tracking flu hospitalizations in 2008. Some are stronger for older people with weaker immune systems and some are made using newer technology. A total of 11,230 people have died from the flu this season alone. That's the highest weekly level CT has seen since the 2009 swine flu pandemic. Despite medical professionals' almost universal recommendation that patients get the flu vaccination, the percentage of those who opt out continues to rise. One bright point for parents of young kids: Children ages 6 months to 8 years responded significantly better to the vaccine than older Americans.

"This flu season continues to be extremely challenging and intense, with very high levels of office visits for flu and hospitalization rates, all indications that flu activity is high and likely to continue for several more weeks", Schuchat said.

To avoid the flu, the EMA recommends people avoid close contact with others who are sick.

However, if you have flu-like symptoms and are in a high risk group, or are very sick or anxious about your illness, contact your health care provider.

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