This article is more than 5 years old. Information may no longer be current.
Influenza illness among elderly contingent upon vaccination of younger adults
Click Here to Manage Email Alerts
Recent findings suggest influenza-related illnesses among older populations may be inversely associated with influenza vaccination rates of younger adults.
“Persons of all ages have contact with the elderly and immunocompromised; for example, in households, on public transportation and in stores,” Glen B. Taksler, PhD, from the Cleveland Clinic Medicine Institute, and colleagues wrote. “Although healthy individuals are at low risk for serious complications from influenza, they may spread disease to others at a higher morbidity or mortality risk. This includes older persons who were vaccinated against influenza, because of modest vaccine effectiveness in the elderly.”
Using data collected by the CDC’s Behavioral Risk Factors Surveillance System Survey, Medicare and the U.S. Census Bureau from 2002 to 2010, the researchers examined the relationship between vaccination and influenza incidence among those aged 65 years and older in select U.S. counties. Coverage rates were determined for 520,229 adults aged 18 to 64 years along with influenza-related illness diagnoses for Medicare beneficiaries.
Countywide vaccination rates were stratified within 5% increments for comparison, and confounding variables such as access to health care, demographics, comorbidity and influenza season severity were assessed. To gauge vaccination among children as a potential variable, coverage data for children aged 6 to 23 years also were drawn from the National Immunization Survey and examined alongside non elderly adults in a separate analysis.
Countywide increases in younger adult vaccination were associated with lower risk for related illness among older adults (P < .001), the researchers wrote. Compared with counties with 15% or fewer young adults vaccinated, the adjusted OR for principal influenza diagnoses among the elderly was 0.91 (95% CI, 0.88-0.94) for counties with 16% to 20% of nonelderly vaccinated and ranged as low as 0.79 (95% CI, 0.76-0.83) in counties with 31% or more of vaccinated nonelderly adults. This effect also was present when analyzing for principal or secondary diagnosis, and for pneumonia or influenza diagnosis. In addition, the association was stronger among older adults who were vaccinated than for those who were unvaccinated.
“For many adults, the decision to be vaccinated is taken to decrease one’s personal influenza-related morbidity and mortality risk,” the researchers wrote. “Our findings suggest that young, healthy persons who obtain vaccination may also protect higher-risk individuals in their community, with the potential to prevent up to 5.9% of influenza diagnoses in elderly individuals.” – by Dave Muoio
- Reference:
- Taksler GB, et al. Clin Infect Dis. 2015;doi:10.1093/cid/civ630.
Disclosure: Taksler reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.