Hello. I'm Dr Sandra Fryhofer. Welcome to Medicine Matters. The topic: flu vaccination 2014, a head-to-head comparison of high-dose vs standard-dose trivalent vaccine in seniors, published in the New England Journal of Medicine. Here's why it matters.
Flu causes, on average, 36,000 deaths and 226,000 hospitalizations each year. Everyone 6 months or older should be vaccinated every year. Those age 65 years or older are particularly vulnerable to flu and flu-related complications. Vaccination is our best bet to prevent flu, but antibody response after vaccination is less robust in older vs younger adults. In December 2009, a high-dose trivalent flu vaccine formulation was FDA approved. It contains four times more hemagglutinin per dose than a standard flu vaccine, but it has downsides: more injection-site reactions and it's double the price.
So, do higher antibody levels with this higher-dose vaccine mean greater flu protection? This new study says yes. The study involved 126 research centers in the United States and Canada and included nearly 32,000 adults 65 years and older during two flu seasons: the 2011-2012 flu season, which had low influenza activity with moderate to good match between vaccine and circulating strains; and the 2012-2013 season, which had high influenza activity as well as a mismatch between vaccine and circulating strains. Patients were randomized to receive either high-dose trivalent or standard-dose trivalent flu vaccine. Blood hemagglutinin inhibition titers were drawn a month after vaccination. The findings: Those receiving high-dose vaccine had significantly higher antibody response to the vaccine. They also looked at who got sick. Overall, 228 persons receiving the high-dose vaccine and 301 receiving standard-dose trivalent vaccine had laboratory-confirmed flu, which translates into a relative efficacy of 24.2%.
The conclusions? In seniors 65 years or older, those receiving high-dose trivalent flu vaccine had better antibody response and better protection against getting sick with flu as compared to those receiving standard trivalent vaccine. This study only involved trivalent preparations; no comparison was made to quadrivalent flu vaccination formulations.
For Medicine Matters, I'm Dr Sandra Fryhofer.
Medscape Internal Medicine © 2014 WebMD, LLC
Cite this: High-Dose Flu Vaccine in Older Adults: Worth It? - Medscape - Oct 07, 2014.