NEW ORLEANS, LA—During the 2013-2014 A/H1N1 dominant flu season, Fluzone High-Dose vaccine reduced the risk of all-cause hospitalization as well as hospitalization for respiratory conditions among long-term care residents, compared with Fluzone standard-dose vaccine, investigators reported at IDWeek 2016.

Noting that response to the flu vaccine declines with age, lead study author Stefan Gravenstein, MD, MPH, of Warren Alpert Medical School, Brown University, in Providence, RI, and colleagues sought to determine whether or not a more immunogenic vaccine would reduce hospitalizations among nursing home residents.

The investigators collected data from the Center for Medicare & Medicaid Services under data-use agreements and from enrolled facilities and analyzed intent-to-treat hospitalization incidence using marginal Poisson regression, accounting for clustering of residents within facilities, and adjusting for a priori facility and resident covariates. Secondary outcomes included mortality and activities of daily living.

The study randomly assigned 823 facilities in 38 states with 53,008 long-stay residents to administer either high-dose or standard-dose vaccines for the 2013–2014 season. Facility and resident characteristics were similar between arms. Analyses included residents age 65 years or older who had lived in the facilities for more than 90 days.

During the study period, flu A/H1N1 was the dominant strain.

The research team found fewer all-cause hospitalizations in high-dose group patients compared with standard-dose facilities for all-causes (5,251 vs. 5,513; P<0.001); adjusted relative risk [RR] was 0.915 (95% CI: 0.863–0.970; P=0.0028). All-causes mortality was similar between the two groups. 

High-dose vaccination “can reduce risk of hospitalization and hospitalization for a respiratory condition in a nursing home population in an A/H1N1-dominant year,” concluded Dr. Gravenstein.