Higher influenza vaccination rates among healthy adults aged 65 years or younger may lower the risk for influenza among older adults who are at greater risk for serious complications from the disease, according to a study published online ahead of print September 9 in Clinical Infectious Diseases.
Lead study author Glen B. Taksler, PhD, and fellow investigators analyzed countywide influenza vaccination rates for 520,229 adults aged 18 years to 64 years and diagnoses of illnesses related to influenza among 3,317,709 Medicare beneficiaries aged 65 years and older across 8 influenza seasons. They found that adults aged older than 65 years were up to 21% less likely to have illnesses that are related to influenza if they lived in areas where more adults younger than age 65 years were immunized.
In counties where at least 31% of adults aged 18 years to 64 years were immunized against influenza, elderly adults had a 21% lower chance of receiving a diagnosis of an illness related to influenza. The reduction in risk for illness related to influenza was more than twice as large for seniors who were also vaccinated against influenza, compared with older adults who were not immunized, suggesting that communitywide vaccination may improve the protection provided by individual vaccination, according to the authors.