Trip Purpose: to immerse new Community Advisory Board member Doug Hirsch in current HIV prevention issues to help him overcome gaps in his background so he can participate more knowledgably in Fenway CAB and HVTN Global CAB activities.
Several keynote speakers pointed to rising seroconversion rates in the Black Community. Among them, there was consensus that external efforts have been largely ineffective due to a combination of cultural issues. Sensitivity to stigma is a major issue. Mistrust of authorities is another. Limited access to health care and educational resources is a factor. The speakers concluded that the Black Community must develop its own sense of ownership of the problem. Community leaders must be brought into the general fight against HIV so they can better help their communities respond.
There is strong consensus within the public health field that needle exchanges significantly reduce rates of seroconversion among IV drug users. Nonetheless these programs often fall victim to the posturing of politicians who want to be seen as hard on drugs. Unfortunately, public opinion is often persuaded by the "tough love" approach that we ought to make IV drug use difficult for users rather than by the statistical argument that fewer cases of AIDS among users means less spread to those whom they infect. It is hard to tell if this is due to callous values ("let Darwin eliminate drug use, damn the collateral damage"), public inability to absorb statistical data, or other factors. The phenomenon points to the importance of keeping political leaders educated on the issues through whatever means they are willing to learn. Public health workers must simultaneously cope with the political structures in which they work and try to influence their leadership to be true to their public purpose. They need everybody's support in this.
HIV has evolved different strains, called clades, which respond differently to treatments. These significantly correlate with geography. Thus, a vaccine that works in Africa won't necessarily work in Europe or America and vice versa. Although conditions in Africa for treatment and vaccine trials are suboptimal, African trials are still crucial to developing tools to deal with the epidemic there. Eventually, when vaccines are shown to be effective in stopping each clade, combinations can be made into multi-clade vaccines.
According to tutorial sessions led by Steve Wakefield and others of the HIV Vaccine Trial Network, there are multiple stages to a drug or vaccine trial. Initially animal trials are used to explore possible efficacy and fundamental safety. Then small scale human trials are used to demonstrate human safety. Once basic safety is established, larger efficacy trials are run to determine whether the approach is worthwhile for human use and to optimize dosage.
A major hurdle in efficacy trials is to discover a marker for success. For example, in AIDS treatment, establishment of the measure of viral load revolutionized the ability to determine the usefulness of new drugs. No such marker has yet been established for HIV vaccine efficacy. The only ways to test an HIV vaccine at this point are to attempt to infect vaccinated volunteers (unacceptable and unethical), or to provide the vaccine to a statistically significant population and to compare the seroconversion rate over time of that population with a similar group given a placebo vaccine. Until the marker is established, these trials will take years. Once the marker is known, the trials can be reduced to months and be made on smaller populations, saving vastly on costs.
There are currently a large number of vaccines under various stages of development. This presents a resource dilemma as to how many huge trials to engage before the marker is discovered enabling more efficient small trials. There is also a human dilemma of how to keep from increasing infection among the trial volunteers who disregard that they do not know if they will actually be protected by the vaccine they received. The powerful psychological effect of denial will be difficult to combat in the informed consent. There is also the conflict of interest inherent to the trial: if no one gets sick, the trial fails.