Taking antiviral drug ‘on demand’ can guard against HIV

HIV infecting an immune cell

POPPING PILLS  Taking antiviral drugs before and after sex can protect people from acquiring HIV, shown here as particles infecting a human immune cell.


For preventing HIV infection, a daily pill may not be needed. Instead, an antiretroviral drug taken before and after sex could get the job done, researchers report in the Dec. 3 New England Journal of Medicine. The treatment plan might be easier for patients, too.

Scientists have previously suggested that a daily dose of antiretroviral drugs guards against HIV infection, but results have been mixed (SN: 11/14/15, p. 14). That’s probably because study participants have a hard time sticking to the regimen, say Jean-Michel Molina of Hôpital Saint-Louis in Paris and colleagues.

So they instructed 199 men at high risk of contracting HIV to take a drug called Truvada two to 24 hours before sex, and then again 24 and 48 hours afterwards. The men were 86 percent less likely to acquire HIV compared with 201 men who took a placebo, the researchers found.

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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