Reports from N.E. Basta and colleagues advance knowledge in vaccine efficacy

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February 2nd, 2009

   2009 FEB 2 -- "In this paper, the authors provide estimates of 4 measures of vaccine efficacy for live, attenuated and inactivated influenza vaccine based on secondary analysis of 5 experimental influenza challenge studies in seronegative adults and community-based vaccine trials. The 4 vaccine efficacy measures are for susceptibility (VES), symptomatic illness given infection (VEP), infection and illness (VESP), and infectiousness (VEI)," scientists in the United States report.

   "The authors also propose a combined (VEC) measure of the reduction in transmission in the entire population based on all of the above efficacy measures. Live influenza vaccine and inactivated vaccine provided similar protection against laboratory-confirmed infection (for live vaccine: VES = 41%, 95% confidence interval (CI): 15, 66; for inactivated vaccine: VES = 43%, 95% CI: 8, 79). Live vaccine had a higher efficacy for illness given infection (VEP = 67%, 95% CI: 24, 100) than inactivated vaccine (VEP = 29%, 95% CI: -19, 76), although the difference was not statistically significant. VESP for the live vaccine was higher than for the inactivated vaccine. VEI estimates were particularly low for these influenza vaccines," wrote N.E. Basta and colleagues.

   The researchers concluded: "VESP and VEC can remain high for both vaccines, even when VEI is relatively low, as long as the other 2 measures of vaccine efficacy are relatively high."

   Basta and colleagues published their study in American Journal of Epidemiology (Estimating Influenza Vaccine Efficacy From Challenge and Community-based Study Data. American Journal of Epidemiology, 2008;168(12):1343-1352).

   For more information, contact I.M. Longini, Fred Hutchinson Cancer Research Center, Vaccine & Infectious Disease Institute, Program Biostatistics & Biomath, 1100 Fairview Avenue N, Seattle, WA 98109, USA.

   Publisher contact information for the American Journal of Epidemiology is: Oxford University Press Inc., Journals Dept., 2001 Evans Rd., Cary, NC 27513, USA.

   Keywords: United States, Seattle, Biotechnology, Communicable Disease, Epidemiology, Flu Vaccines, Human Influenza, Immunization, Influenza Vaccines, Vaccination, Vaccine Efficacy.

   This article was prepared by Pharma Business Week editors from staff and other reports. Copyright 2009, Pharma Business Week via NewsRx.com.

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