Opening Session
Reported by Jules Levin

I just returned from the opening session for the conference where Joseph Sodroski of the Dana Farber Cancer Institute at Harvard Medical School discussed binding and fusion between HIV and cells. Sodroski reported how research has allowed us to dramatically improve our understanding of the very complicated process of virus binding and fusion with cells allowing insertion of HIV into the CD4 cell. With this understanding research is trying to identify targets for interventions with treatment to inhibit or prevent binding and fusion. T-20 is a fusion inhibitor in early stages of human trial and has exhibited potent antiviral activity. Encouraging data from a trial of T-20 will be presented at this conference. The development of additional fusion inhibitors is in progress and reports will be made at this conference.

Beatrice Hahn from the University of Alabama-Birmingham reported, at the opening session, research leading to the belief that the origin of HIV-1 is from chimpanzees native to West-Central Africa. The study by a group of researchers led by Hahn is reported in the current issue of the journal Nature. Hahn reports that she and her colleagues have concluded that a certain type of chimpamzee has been the source of transmission of HIV from chimpanzees to humans. Since these chimps contract HIV but don't get AIDS a better understanding of exactly how the chimp's immune system responds to HIV might lead to strategies for developing vaccines or improved treatment of HIV for humans. Hahn said that the hunting and killing of these chimps for human consumption is a common practice in West-Central Africa and represents an ongoing risk for humans. She said she hopes these research findings lead to measures to discourage these practices of hunting and consuming these chimps.

Earlier today the conference organizers held their usual pre-conference press conference. Representatives from UNAIDS reported important results from an international perinatal transmission study. Three therapeutic approaches of administering AZT+3TC were used in this study to prevent HIV transmission from mother to child: (1) starting AZT+3TC at week 36 of pregnancy, through delivery and then 1 week after delivery for the child for a total of 5 weeks therapy; (2) starting therapy at the onset of labor and during delivery and for 1 week after delivery for the child for a total of 1 week of therapy; (3) stating therapy at onset of labor and during delivery only.

Using the first method there was a transmission rate of 17.2% in individuals receiving placebo in the study vs 8.6% transmission for those receiving AZT/3TC. Using the second method the transmission rate was 17.2% for those receiving placebo and 10.8% for those receiving AZT+3TC. There was no difference between placebo and treatment for those using the third method. Since some women don't present themselves as being HIV+ until they are ready for delivery method 2 may be an effective approach for preventing transmission. The reduced amount of time of therapy in methods 1 and 2 compared to the model used in study 076 will be much less expensive. This cost effectiveness will be applicable in underdeveloped countries. As well, Glaxo Wellcome has committed to making the drugs available at a reduced cost. These advances should go a long way to reducing HIV incidence in the future in third world countries. The UNAIDS officials stated, however, that it is premature to draw policy conclusions from this data.