Influenza Vaccine

New flu vaccines data have been reported by K.L. Nichol and co-authors

Influenza Vaccine Library Library Home This article was published in Pharma Business Week, which you can subscribe to online.

"This study examined the effectiveness of influenza vaccine in seniors over the long term while addressing potential bias and residual confounding in the results. Methods Data were pooled from 18 cohorts of community-dwelling elderly members of one USA. health maintenance organization (HMO) for 1990-1991 through 1999-2000 and of two other HMOs for 1996-1997 through 1999-2000. Logistic regression was used to estimate the effectiveness of the vaccine for the prevention of hospitalization for pneumonia or influenza and death after adjustment for important covariates. Additional analyses explored for evidence of bias and the potential effect of residual confounding. Results There were 713,872 person-seasons of observation. Most high-risk medical conditions that were measured were more prevalent among vaccinated than among unvaccinated persons. Vaccination was associated with a 27% reduction in the risk of hospitalization for pneumonia or influenza (adjusted odds ratio, 0.73; 95% confidence interval [CI], 0.68 to 0.77) and a 48% reduction in the risk of death (adjusted odds ratio, 0.52; 95% CI, 0.50 to 0.55). Estimates were generally stable across age and risk subgroups. In the sensitivity analyses, we modeled the effect of a hypothetical unmeasured confounder that would have caused overestimation of vaccine effectiveness in the main analysis; vaccination was still associated with statistically significant - though lower - reductions in the risks of both hospitalization and death. Conclusions During 10 seasons, influenza vaccination was associated with significant reductions in the risk of hospitalization for pneumonia or influenza and in the risk of death among community-dwelling elderly persons," wrote K.L. Nichol and colleagues.

The researchers concluded: "Vaccine delivery to this high-priority group should be improved."

Nichol and colleagues published their study in New U.K. Journal of Medicine (Effectiveness of influenza vaccine in the community-dwelling elderly. New U.K. Journal of Medicine, 2007;357(14):1373-1381).

For additional information, contact K.L. Nichol, VA Med Center, Medical Service, 111, 1 Vet. Dr., Minneapolis, MN 55417, USA.

Publisher contact information for the New U.K. Journal of Medicine is: Massachusetts Medical Society, Waltham Woods Center, 860 Winter St., Waltham, MA 02451-1413, USA.

Keywords: United States, Minneapolis, Flu Vaccines, Immunization, Influenza Vaccines, Vaccination.

This article was prepared by Pharma Business Week editors from staff and other reports. Copyright 2007, Pharma Business Week via NewsRx.com.