Vaccine clinical trials are long-term studies aimed at assessing the safety, efficacy and immunogenicity of a new vaccine product. Sometimes trials also assess how well the product meshes with existing healthcare delivery systems, such as national immunization programs.
The clinical trials that are conducted to prevent the transmission of Human Immunodeficiency Virus come under Vaccine Clinical Trials. These trials can benefit humans by reducing an HIV-negative individual’s risk of acquiring HIV; reducing an HIV-positive individual’s risk of transmitting HIV; and reducing HIV viral load in a person who received the intervention when he or she was HIV-negative, and later became HIV-positive through sexual or other exposure. But there are lot of misconceptions about HIV vaccine clinical trials since most people believe that participating in such trials increases the probability of HIV transmission.
The reason behind this is, many biomedical prevention trials enroll HIV-negative volunteers and evaluate new strategies to see if they reduce volunteers’ risk of becoming HIV-infected. The enrolment of HIV negative individuals provides the community education which allows people to learn about the goals of the trial and decide whether they might want to volunteer. Potential volunteers visit the trial site and learn more about the trial and trial procedures. They may enroll into the study if they find the trial would be beneficial for them. Those who meet the eligibility criteria and pass the screening tests will get enrolled in the trial after providing their informed consent. Informed consent process is an important process that should continue throughout the trial.
The majority of biomedical HIV prevention trials are double-blind, which means that neither the participant nor the trial staff knows which subject is receiving the investigational agent or placebo—and all trial participants are counselled that there is no way of knowing whether they received the placebo or experimental vaccine candidate. Hence this creates a major misconception that participants may receive the investigational agent and may become prone to HIV infection due to participation. Because of these misconceptions, a HIV vaccine trial has been called off before completion in 2009, as reported by September 2011 edition of the American Journal of Public Health.