This was presented as a poster presentation at the IX International Symposium on Respiratory Viral Infections, March 3–6, 2007, Causeway Bay, Hong Kong.
Flu: Effect of Vaccine in Elderly Care Home Residents: A Randomized Trial
Article first published online: 7 DEC 2007
Journal of the American Geriatrics Society
Volume 55, Issue 12, pages 1912–1920, December 2007
How to Cite
Gaughran, F., Walwyn, R., Lambkin-Williams, R., Whelan, P., Chatterton, K., Oxford, J., Macdonald, A. and for the Flu—Effect of Vaccine in Elderly Residents Trial team (2007), Flu: Effect of Vaccine in Elderly Care Home Residents: A Randomized Trial. Journal of the American Geriatrics Society, 55: 1912–1920. doi: 10.1111/j.1532-5415.2007.01471.x
- Issue published online: 7 DEC 2007
- Article first published online: 7 DEC 2007
- influenza vaccination;
- booster dose;
- hemagglutination titers;
OBJECTIVES: To determine whether assessing seroprotection after influenza vaccine and administering booster vaccination where not achieved reduces hospitalization and death. To estimate the overall seroprotection rate of influenza vaccine.
DESIGN: A two-arm, partially blind, randomized, multicenter, parallel-group, controlled trial.
SETTING: Twenty-six care homes in three South London boroughs in fall 2004.
PARTICIPANTS: Two hundred seventy-seven elderly permanent care home residents meeting eligibility criteria.
INTERVENTION: Postvaccination blood samples were randomized to booster evaluation or no booster evaluation (control). If evaluation revealed inadequate seroprotection, a booster vaccine was administered.
MEASUREMENTS: Primary outcome was hospitalization to end April 2005; secondary outcomes were death, antibiotic use, and seroprotection.
RESULTS: Sixty percent of the controls and 41% of the booster evaluation group responded to routine vaccination. Booster vaccination where indicated increased seroprotection rates in the booster evaluation group to 66%. Treatment groups did not differ in any outcome measures in the intention-to-treat analysis (hospitalization odds ratio=1.02, 95% confidence interval=0.55–1.87). There was a tendency towards greater differences between groups in the per-protocol analysis than in the intention-to-treat analysis, particularly regarding seroprotection rates. The same effect was observed in the a priori exploratory analysis of residents not seroprotected after routine vaccination alone.
CONCLUSION: In a year without circulating influenza, there is no clinical benefit of administering a booster vaccine if routine trivalent vaccination fails to result in seroprotection. Hemagglutination titers rose in two strains postbooster vaccination but fell against the novel strain, Wyoming. The benefit of such a booster strategy when influenza is prevalent thus remains unc ertain.