Adverse reactions to influenza vaccine in elderly people: randomised double blind placebo controlled trial.

Abstract

OBJECTIVE--To assess the frequency and type of side effects after influenza vaccination in elderly people. DESIGN--Randomised double blind placebo controlled study. SETTING--15 general practices in the southern Netherlands. SUBJECTS--1806 patients aged 60 or older, of whom 904 received influenza vaccine and 902 placebo. MAIN OUTCOME MEASURES--Adverse reactions reported on postal questionnaire completed four weeks after vaccination. RESULTS--210 (23%) patients given vaccine reported one or more adverse reactions compared with 127 (14%) given placebo. The frequency of local adverse reactions were 17.5% in the vaccine group and 7.3% in the placebo group (p < 0.001). There was no difference in systemic adverse reactions (11% v 9.4%; p = 0.34). In general, men reported fewer side effects than women. CONCLUSION--Only local side effects were more common in vaccinated patients and all side effects were mild.