Hoang An
More than 40% of over-65s in the US use statins to control cholesterol, but two new studies suggest that statin use decreases the effect of the flu vaccine, according to findings published in The Journal of Infectious Diseases.
A high-dose flu vaccine is one of several standard-dose vaccines approved for adults over 65 in the US. The Centers for Disease Control and Prevention (CDC) recommend that everyone be vaccinated against flu every season from the age of 6 months. Seniors are at particular risk for serious illness and complications from flu, including death.
However, one of the new reports shows that many senior statin users had a significantly reduced immune response to the vaccination, compared with those not taking statins. In the other study, effectiveness at preventing serious respiratory illness was lower among patients taking statins.
One group of researchers analyzed immune response data from an earlier flu vaccine clinical trial conducted during the 2009-10 and 2010-11 flu seasons.
They focused on the potential effect of statin use on patients' initial immune responses after being immunized against flu. The study involved nearly 7,000 adults over the age 65 in four countries, including the US.
Reduced immune response in statin usersStatin users were found to have a significantly reduced immune response to vaccination compared with those not taking statins, as measured by the level of antibodies to the flu vaccine strains in patients' blood 3 weeks after vaccination.
Fast facts about flu
- 70% of Americans aged 65 and over have had a flu vaccine in the last 12 months
- 3,697 people died from flu in the US in 2013
- The mortality rate for the US is 1.21 people in every 100,000.
Learn more about flu
The effect was most dramatic in patients on synthetic rather than naturally derived statins.
If confirmed, the findings could support the use of high-dose flu vaccine or vaccines containing adjuvants to boost immune response in older people.
Vaccines containing adjuvants have already been approved in Europe, but not yet in the US.
In the vaccine effectiveness study, researchers from Emory University in Atl