Side effects of influenza vaccination in healthy older people: A randomised single-blind placebo-controlled trial

Objectives: To investigate the frequency of side effects following influenz a vaccination in healthy participants aged 65-74 years. Materials and Metho ds: A single-blind randomised placebo-controlled trial was performed in gen eral practices in central Liverpool on 729 healthy individuals (341 females and 388 males) aged 65-74 (median age 68.9) years, of whom 552 received in fluenza vaccine and 177 received placebo. The main outcome measures were an alysed from adverse reactions reported by the subjects on a postal question naire 3 days after vaccination. Results: 724 (99.3%) questionnaires were re turned. 62 (11.3%) participants who received influenza vaccination complain ed of local symptoms compared with 9 (5.1%) participants who received place bo (difference 6.2%;95% Cl 1.3 to 10.0%; p=0.02). 192(35.1%)individuals who received influenza vaccine complained of one or more systemic side effects compared with 75 (42.4%) who received placebo (difference -7.3%; 95% Cl - 15.6 to 0.9%; p = 0.10). Conclusion: Healthy people belonging to this age g roup can be reassured that, when compared with placebo, influenza vaccinati on causes few, if any, systemic side effects and only a low incidence of lo cal side effects. Copyright (C) 2001 S. Karger AG, Basel.