Older Veterans Benefit More From High-Dose Flu Shots

Senior veterans reduced all-cause hospitalizations by 10% with high-dose influenza vaccine
honor guard older vet with flag

A new analysis found a high-dose influenza vaccine was more effective in helping older adults avoid serious health outcomes when compared to standard-dose (SD) flu vaccines. 

This study found overall high-dose (HD) flu vaccinations were more effective in preventing hospitalizations caused by the flu, pneumonia, cardiorespiratory conditions, and all-cause hospitalizations. 

These researchers said this ‘study is the first longitudinal multi-season comparative effectiveness analysis of HD versus SD vaccine, with clinical data collected from approximately 1.7 million US veterans, who were 65 years of age or older. 

Based on the longitudinal analysis of 5 flu seasons, this study reported: 

  • IV-adjusted relative vaccine effectiveness estimate of HD vs. SD was 10 percent against all-cause hospitalization
  • 18 percent against cardiorespiratory-associated hospitalization
  • 14 percent against influenza/pneumonia-associated hospitalization

In aggregate, these researchers analyzed data from approximately 3.6 million older adults across 5 flu seasons, 2010-11 through 2014-15. As of 2012, veterans age 65 or older numbered in excess of 12.4 million.   

Veterans are defined as individuals who have been honorably discharged from the Army, Navy, Marines, Air Force, and Coast Guard, of whom 8.8 million are enrolled for benefits with VHA. 

The data for this study came from Veterans Health Administration EMR records, which have a lower risk of up-coding, and from Medicare claims data, in order to have as complete a record as possible of all healthcare encounters that occurred for our study population. 

Previous clinical trials have shown that HD was 7 percent and 8 percent more effective than SD influenza vaccine in preventing all-cause hospital admissions in ambulatory and nursing home seniors, respectively. 

Human immune defenses naturally decline with advancing age, which can cause a diminished immune response to vaccines. This natural decline also means that older adults are particularly vulnerable to influenza infection and its complications. 

In the USA, Fluzone HD flu vaccine contains 4 times more influenza hemagglutinin antigen than standard-dose influenza vaccines (SD; 60 μg vs. 15 μg per strain), designed to provide improved protection in seniors. 

Fluzone High-Dose is not recommended for persons with a history of severe allergic reaction to the vaccine or to components other than eggs, reports Sanofi. 

Vaccines, like any medicine, can have side effects, says the CDC. You are encouraged to report negative side effects of vaccines to the FDA or CDC.