The effect of behavior change on estimates of prophylactic HIV vaccine efficacy in field trials. NLM AIDSLINE Important note: Information in this article was accurate in 1993. The state of the art may have changed since the publication date.

Click here to return to AIDSLINE main menu
DonateNow
Print this Article


The effect of behavior change on estimates of prophylactic HIV vaccine efficacy in field trials.

Int Conf AIDS. 1993 Jun 6-11;9(1):101 (abstract no. WS-C20-5). Unique Identifier : AIDSLINE MED/93333231
Halloran E; Longini I; Struchiner C; Haber M; Brunet R; Emory School of Public Health, Atlanta.

Abstract: OBJECTIVES: To estimate the bias in prophylactic HIV vaccine efficacy (VE) estimates when vaccinated people increase their exposure to infection. METHODS: Simulations are conducted for blinded and unblinded VE trials with different levels and distributions of behavior change and protection against infection. VE estimators are based on transmission probabilities TP), hazard rates, or attack rates (AR). RESULTS: In simulations with 0.50, 0.70, and 0.95 of the vaccinated completely protected, and in a blinded study in which only tested responders change behavior, the VE estimator based on AR's is unbiased, while in an unblinded study when half of the vaccinated increase infectious contacts two-fold, the estimated VE's based on AR's are 0.26, 0.56, and 0.93, respectively. In simulations with the same behavior change but homogeneous reduction of susceptibility by 0.50, 0.70, and 0.95, VE estimators based on TP's are unbiased; but those based on hazard rates are 0.25, 0.55, and 0.93. CONCLUSIONS: Estimators at high VE's and estimators based on TP's are least biased. With heterogeneous response to the vaccine, unblinded studies can result in more bias in VE estimates than blinded studies.
Keywords: *AIDS Vaccines/THERAPEUTIC USE *Sex Behavior *Social BehaviorKWDaidsvaccines/therapeuticuseKWDsexbehaviorKWDsocialbehavior
931130
M93B5816

Copyright © 1993 - National Library of Medicine. Reproduced under license with the National Library of Medicine, Bethesda, MD.

AEGiS is a 501(c)3, not-for-profit, tax-exempt, educational corporation. AEGiS is made possible through unrestricted funding from Boehringer Ingelheim, Bridgestone/Firestone Charitable Trust, Bristol-Myers Squibb Company, Elton John AIDS Foundation, Gill Foundation, the National Library of Medicine, Quest Diagnostics, Roche and Trimeris, and donations from users like you. Always watch for outdated information. This article first appeared in 1993. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 1993. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .