Revealed: Why the flu vaccine is less effective in older people

You might get your vaccine every flu season but that doesn’t mean you are immune to getting it… and now we know why.

It can strike us at any time during the year, however flu season generally coincides with a change of season.

A study published by Cell Press on December 15th 2015 in Immunity explains why the flu vaccine is less effective at protecting older individuals.

Flu vaccines, which contain proteins found in circulating viral strains, offer protection by producing antibodies, which help the immune system protect against infectious disease. While vaccination is considered the most effective method for preventing influenza, it is less effective in the elderly and now we know why.

Researchers vaccinated 212 subjects, including 54 elderly individuals, across five influenza vaccine seasons, from 2007 to 2011, and analysed blood samples to identify molecular pathways associated with protective antibody responses elicited by vaccination.

Within one week of flu vaccination, younger people showed high levels of antibody-producing B cells, whereas the elderly showed high levels of immune cells called monocytes, which give an inflammatory response in the body.

These age-related differences predicted vaccine-induced immune responses observed in the elderly three weeks later.

“While it is early to suggest, supplementary therapeutic approaches, such as reducing the inflammatory response in elderly patients after vaccination, would be valuable avenues to pursue. However, this warrants longer and more detailed investigations”, said co-author Shankar Subramaniam.

The researchers now plan on doing similar studies on shingles and yellow fever.

But don’t stop getting your flu shot yet: it’s still recommended for over 65s.

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