Interesting to see how different outlets present different things, isn't it?
From USA Today: USATODAY.com - Vaccine for AIDS appears to work: Nearly two decades after the discovery of the AIDS virus, researchers today report for the first time that an AIDS vaccine can prevent infection but with sharply different success rates depending on race. The first full-scale human trial of the vaccine, AIDSVAX, indicates that although the vaccine failed to protect whites and Hispanics, it appears to be effective in blacks, though the number of black volunteers was small. Blacks account for half of all new infections in the USA, federal statistics show.
And then we have the New York Times (registration required).
Large Trial Finds AIDS Vaccine Fails to Stop Infection: The first AIDS vaccine ever to be tested in a large number of people has failed, over all, to protect them from infection with the virus that causes the disease, the company that makes it, VaxGen, said today. The vaccine did, however, seem to significantly lower the infection rate among African-Americans and other non-Hispanic minorities participating in the trial, the company said. Its researchers called this finding totally unexpected and said they were at a loss to explain why there would be ethnic differences in response to the vaccine. They conceded that the findings, though statistically significant, might change if the vaccine were tested among more members of minorities, who were only a small fraction of the people in the trial.
For some reason, USA Today has something invested in putting the best possible face on the results, while the Times has something invested in appearing more cynical.
The study also highlights the ethical problems of doing this type of vaccine study, although nobody would put it quite that way.
Two-thirds of the participants were given a series of seven shots over three years, while the other third were given the same number of placebo injections. The goal was to see if the people who received the vaccine would have a lower rate of infection. In the overall population of participants, 5.8 percent of those who received the placebo became infected, compared with 5.7 percent of those who received the vaccine. The difference was not statistically significant. But among black, Asian and other minorities the rate of infection was only 3.7 percent in the vaccinated group, compared with 9.9 percent in the placebo group.
Interestingly, one of the fears of doing this type of study does not seem to have come to pass. Apparently, people did not change their sexual behavior, expecting that they were protected by the vaccine.
All of the participants were counseled on safer sex and other ways to protect themselves from infection with H.I.V. Some critics of vaccine trials have said they feared that participants might abandon such protective measures out of a false hope that they had received a vaccine that would protect them. This study found no evidence for these fears.
Of course ... that would seem to mean that we can expect a roughly 10% rate of HIV infection in higher-risk groups as a reasonable standard, which is sort of appalling, really.
The part of the test on 2500 drug-injecting Thais (how on earth did they come up with that sample?) should, if nothing else, partially answer the question on sample size for Asians.
Posted by iain at February 24, 2003 12:03 PMComments
