Journal of medical virology
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Randomized Controlled Trial Clinical Trial
Randomized controlled trial of seroresponses to double dose and booster influenza vaccination in frail elderly subjects.
Responses to influenza vaccination are poor in frail elderly subjects who suffer the greatest morbidity and mortality due to infection. Therefore, a randomized clinical trial was performed to determine the effect of a double dose and booster vaccination on antibody responses after influenza vaccination. A total of 815 patients (median age 83 years, median disability score 8, median disease categories 2 and median number of medications 4) residing in 14 nursing homes in the Netherlands were vaccinated during the influenza season 1997-98. ⋯ A booster dose, given 84 days after the first vaccination, yielded postvaccination titters that were 14% (95% CI, 9% to 19%, P = 0.001) higher as compared to placebo. Subgroup analysis did not reveal patient groups that had a proportionally greater benefit from adapted vaccination strategies. It is concluded that higher antibody responses can be achieved in frail elderly people by a double vaccine dose or a booster vaccination.