Protection against influenza after annually repeated vaccination

The protection rate against influenza appers not to decrease over years when vaccination is given annually.

A systematic review including 7 studies (10 trials) with a total of 5117 subjects in the field studies and 52 trials with a total of 12,341 subjects in serologic studies was abstracted in DARE. The study question was whether the protection rate decreases if vaccinations are repeated annually. The pooled protection-rate difference in field studies was close to 0, thus detecting no difference between single and multiple vaccinations. In the serologic studies, 9 trials were significantly in favour of single vaccination, and 7 trials were in favour of multiple vaccination.

Comment: The quality of evidence is downgraded by indirectness of evidence (mostly surrogate (serological) outcomes).

The following decision support rules contain links to this evidence summary:

• Influenza vaccination for the elderly
• Influenza vaccination for risk groups

Ədəbiyyat

1. Beyer WE, de Bruijn IA, Palache AM, Westendorp RG, Osterhaus AD. Protection against influenza after annually repeated vaccination: a meta-analysis of serologic and field studies. Arch Intern Med 1999 Jan 25;159(2):182-8.