The New England Journal has just released a new study that adds to our knowledge of HIV prevention, albeit not in a positive way. It is another example of how science works. Pseudoscience, such as that preferred by HIV denialists and creation cult followers, doesn’t require logic or scientific method. Negative results are usually explained away under various excuses. Not so with this study. Lets go over it, shall we?
The study starts with an interesting hypothesis. It has been observed that HIV is more easily acquired in the setting of other sexually transmitted diseases, among these genital herpes (HSV-2). We know how to reduce the incidence of HSV outbreaks in patients previously infected with the virus. This study looked at high risk women with HSV, gave half of them appropriate prophylaxis, and half of them placebo. The end point studied was new infection with HIV.
Despite the use of effective HSV prophylaxis, there was no difference in HIV acquisition rates between the two groups of women. This doesn’t rule out any benefit, but per the authors’ analysis, the study design should have picked up any moderate or strong preventative effect of the medication.
The results are disappointing—it would have been nice to be able to give a cheap, well-tolerated drug to at-risk individuals to prevent HIV, but in this case, it didn’t help. This doesn’t mean that preventing STDs will not prevent some cases of HIV. The results indicated that in similar populations (at-risk East African women), prevention of herpes outbreaks with standard medications didn’t reduce HIV infections. No further extrapolations can be made.
This is the difference between science and bullshit. Science evaluates a hypothesis, and if it is not supported after repeated tests, the hypothesis is rejected. Pseudoscience just makes excuses and moves the goalposts.
References
Watson-Jones, D., Weiss, H.A., Rusizoka, M., Changalucha, J., Baisley, K., Mugeye, K., Tanton, C., Ross, D., Everett, D., Clayton, T., Balira, R., Knight, L., Hambleton, I., Le Goff, J., Belec, L., Hayes, R. (2008). Effect of Herpes Simplex Suppression on Incidence of HIV among Women in Tanzania. New England Journal of Medicine DOI: 10.1056/NEJMoa0800260
