December 14, 2006
A hetero-only AIDS vaccine?
Posted by: Chris
Two clinical trials have been halted midstream after it became clear that circumcision reduced by at least half a man's risk of contracting the AIDS virus, at least in heterosexual sex. Officials with the U.S. National Institutes of Health stopped the trials, in Kenya and Uganda, after learning that more than twice the number of uncircumcised men had contracted HIV than in a similar sized circumscribed group. The New York Times reports:
Uncircumcised men are thought to be more susceptible because the underside of the foreskin is rich in Langerhans cells, sentinel cells of the immune system, which attach easily to the human immunodeficiency virus, which causes AIDS. The foreskin also often suffers small tears during intercourse.
The protection offered by circumcision in anal sex is murkier. Anthony Fauci, the famous AIDS researcher and director of the NIH's National Institute of Allergy & Infectious Diseases, told the Times that circumcision "does nothing to prevent spread by anal sex." But a Q&A fact sheet provided by Fauci's agency indicates, "The degree of protection that circumcision may afford for men who have sex with men is unknown." Still, even if circumcision helps protect the active partner (the "top") in homosexual anal sex, the effect will be at the margins, at least in the U.S., where 77 percent of men are already circumcised.
The new NIH study confirms findings from an earlier South African study that concluded circumcised men were 65 percent less likely to contract HIV from vaginal sex than those whose penises are uncut. Francois Venter, a South African AIDS expert at the University of Witwatersrand, made headlines in September 2005 by comparing the effectiveness of circumcision to that of a vaccine.
"We dream of a vaccine which has this efficacy," Venter said then. Indeed, most "AIDS vaccines" that have been approved for any level of clinical trial never even claim to achieve protection in as many as 65 percent of those "vaccinated." Still, Venter's use of the vaccine comparison was roundly criticized for suggesting circumcision provided complete protection. That's a dangerous suggestion, especially considering that it only improves protection odds for men, not women, although women would be indirectly benefited by a decrease in the number of infected men generally.
Played out on a scale of millions, circumcision would no doubt save many lives, especially if the expanded use of microbicides provide anything like the level of protection for women that scientists hope. There are clear scientific reasons why heterosexual, vaginal sex is more easily made safer, since anal sex invariably involves more tissue breakage, both because the anal opening is smaller and the receptive tissue is much more sensitive and thin.
But rest assured that some opportunistic religious leaders will nonetheless leap to moral conclusions about what sex is "natural" or sinful. (Also rest assured, believe it or not, that anti-circumcision groups, often led by gay men, will recklessly try to debunk the new science as encouraging what they call "male genital mutilation.")
It's not difficult to imagine, over the next five to 10 years, that circumcision and microbicides dramatically reduce the risk of HIV infection from heterosexual sex, making anal sex and I.V. drug use again the most prevalent forms of transmission worldwide. We'll see if the AIDS, Inc., industry continues pressing for ways to make homosexual sex just as safe. You can certainly imagine that a grant request with that as a stated goal is much less likely to get government funding.
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