Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Available influenza vaccines contain inactivated viruses, either whole or in parts, are administered parenterally or intranasally. Their composition varies yearly because of viral antigenic shifts and drifts. Vaccines with a composition matching yearly World Health Organization recommendations are 72% [95% confidence interval (CI) = 54-83%] efficacious (prevention of influenza cases caused by influenza viruses A and B). Their effectiveness [capacity to prevent clinical influenza, or influenza-like illness (ILI)] is lower, at 37% (95% CI = 18-52%). A decision to vaccinate an adult population has to take into account the efficacy of the vaccines and their effectiveness (the likely proportion of ILI caused by influenza A and B viruses, amenable to prevention by vaccination), as well as costs and likely compliance. As the yearly levels of circulating A and B viruses are difficult to predict during the decision time for a vaccination campaign, there is a considerable element of uncertainty regarding the likely effectiveness of 'this year's' vaccine.

Original publication

DOI

10.1093/occmed/52.5.255

Type

Journal article

Journal

Occupational Medicine

Publication Date

01/08/2002

Volume

52

Pages

255 - 258