Journal of Infectious Diseases
15 July 2009 Volume 200, Number 2
Influenza Vaccines for Elderly Individuals—An Evolving Story
Gregory A. Poland and Mark J. Mulligan
[No abstract published]
Randomized, Double-Blind Controlled Phase 3 Trial Comparing the Immunogenicity of High-Dose and Standard-Dose Influenza Vaccine in Adults 65 Years of Age and Older
Ann R. Falsey,1,2; John J. Treanor,2; Nadia Tornieporth,3; Jose Capellan,5 and Geoffrey J. Gorse4
1Department of Medicine, Rochester General Hospital and 2University of Rochester School of Medicine, Rochester, New York; 3sanofi pasteur, Swiftwater, Pennsylvania; 4Saint Louis Department of Veterans Affairs Medical Center and Saint Louis University, Saint Louis, Missouri; 5sanofi pasteur, Toronto, Canada
Background.Influenza‐associated morbidity and mortality has not decreased in the last decade, despite increased receipt of vaccine. To improve the immunogenicity of influenza vaccine, a high‐dose (HD) trivalent, inactivated influenza vaccine was developed.
Methods.A multicenter, randomized, double‐blind controlled study was conducted to compare HD vaccine (which contains 60 μg of hemagglutinin per strain) with the licensed standard‐dose (SD) vaccine (which contains 15 μg of hemagglutinin per strain) in adults 65 years of age.
Results.HD vaccine was administered to 2575 subjects, and SD vaccine was administered to 1262 subjects. There was a statistically significant increase in the rates of seroconversion and mean hemagglutination inhibition titers at day 28 after vaccination among those who received HD vaccine, compared with those who received SD vaccine. Mean postvaccination titers for individuals who received HD vaccine were 116 for H1N1, 609 for H3N2, and 69 for B strain; for those who received SD vaccine, mean postvaccination titers were as 67 for H1N1, 333 for H3N2, and 52 for B strain. The HD vaccine met superiority criteria for both A strains, and the responses for B strain met noninferiority criteria. Seroprotection rates were also higher for those who received HD vaccine than for those who received SD vaccine vaccine, for all strains. Local reactions were more frequent in individuals who received HD vaccine, but the reactions were mild to moderate.
Conclusions.There was a statistically significant increase in the level of antibody response induced by HD influenza vaccine, compared with that induced by SD vaccine, without an attendant increase in the rate or severity of clinically relevant adverse reactions. These results suggest that the high‐dose vaccine may provide improved protective benefits for older adults.
Trial registration.ClinicalTrials.gov identifier: NCT00391053.