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close this bookUNAIDS-Sponsored Regional Workshops to Discuss Ethical Issues in Preventive HIV Vaccine Trials (UNAIDS, 2000, 52 p.)
close this folderWORKSHOP REPORTS
close this folderBANGKOK, THAILAND, 20-22 APRIL, 1998
View the document1. Collaboration in Phase I, II and III Trials
View the document2. Community
View the document3. Ethical and Scientific Review
View the document4. Intellectual Property
View the document5. Control Arm in Trials
View the document6. Informed Consent
View the document7. Gender, Pregnancy and Breast-Feeding
View the document8. Children
View the document9. Protection from Discrimination
View the document10. Vaccine-Induced HIV-Seropositivity
View the document11. Counselling
View the document12. Post-Exposure Prophylaxis (PEP)
View the document13. Treatment and Care
View the document14. Compensation
View the document15. Availability of Vaccine

5. Control Arm in Trials

Consensus:

Use of a substance that is not active against HIV in the control arm of a preventive HIV vaccine trial is scientifically and ethically acceptable in the absence of proven effective preventive HIV vaccines.

Controversy:

Some participants were concerned about the lack of benefit that results from being randomized to placebo. It was suggested that another vaccine such as hepatitis B or tetanus vaccine could be given to participants in the control arm, for the sake of increasing benefit. The choice of vaccine would need to be appropriate for the population (i.e. a vaccine should not be given against a disease for which there already exists significant immunity in the population.) However, some participants were of the opinion that those in the control arm should not be treated any differently from those in the treatment arm of the trial. This argument rested on the principle that both arms deserve equal benefit (the treatment arm is not receiving a proven benefit), and that scientific interpretation of the results may be clouded by providing vaccination against a disease other than HIV.

It was suggested that the scientific community might rely too readily on the power of randomized placebo-control trials, and that there needs to be encouragement to consider other study designs that could provide adequate data without the risks inherent in randomization.

In some cultures, participants feel cheated if they are aware they may be receiving a placebo.