Thirty-eight million people around the globe are infected with HIV, and 8,000 of them die each day from AIDS. Although anti-HIV drugs can extend lives, they have serious limitations, and the vast majority of infected people still do not have access to them. So it is hard to overstate the need for an AIDS vaccine that c an slow the virus’s spread and ultimately safeguard the world’s population.
Scientists in academia, government, and the pharmaceutical industry have spent the last 18 years testing three dozen different AIDS vaccines in human studies. Time and again, high hopes have given way to crushing disappointments, and the field has been roiled repeatedly by bitter disputes about the best way to move forward. If the different players worked in isolation, as private companies often do, the tensions might not matter much. But in the world of international vaccine research, there’s a constant tussle for resources and influence among government agencies, universities, drug companies, health ministries, networks of clinics, and the communities that agree to participate.
Keeping this tussle from devolving into self-defeating conflict depends on consultation and coordination among all parties. But that’s easier said than done, as was dramatically illustrated by an AIDS-vaccine trial launched in Thailand in 2004 with U.S. government backing. The study – the largest, most expensive AIDS vaccine trial in history – has turned out to be a model of bad communication, scientific disagreement, international face-saving, and clashing bureaucratic interests. Many leading AIDS researchers have publicly decried the trial as a near-certain failure and a waste of scarce resources.
The trial combines two different vaccines, and although critics don’t particularly like either of them, they dislike one more than the other – and that has become the main point of contention. The controversial vaccine, called gp120, was once the darling of the field, but it fell out of favor more than a decade ago, after disappointing test results. It survives because indefatigable corporate and government scientists have brought it back time and again, arguing that it deserves yet another study to assess its worth. General scientific opinion would have dictated otherwise.
The saga began in the summer of 1993, when a protein called gp120 enjoyed frontrunner status in a spirited race to develop an AIDS vaccine. The protein sticks out from the surface of the HIV virus like the hooks in Velcro, allowing it to latch onto and infect human cells. Biotech stars Genentech and Chiron believed that injecting the surface protein into people would stimulate their immune systems to create antibodies against it, theoretically protecting them if they contracted the virus. The U.S. National Institutes of Health (NIH) planned to bankroll efficacy trials.
Then gp120’s fate suddenly turned. In test-tube experiments reported in October 1993, antibodies taken from vaccinated people proved unable to stop HIV from infecting human cells. After consulting widely with critics of the approach, NIH decided in June 1994 to abandon plans for the multimillion-dollar efficacy trials.
The decision spelled the end of the gp120 programs at both companies, but out of the ashes of the Genentech effort rose VaxGen, which raised millions of private dollars to stage two new efficacy trials. Though no less a personage than Nobel laureate David Baltimore, who in 1998 headed NIH’s AIDS Vaccine Research Committee, expressed serious doubts about gp120’s utility, VaxGen charged that its critics put too much faith in their theories and not enough in the good old trial-and-error empiricism that had guided research on other vaccines.