A tiny implant may prevent a person from getting HIV for a year, reports the New York Times.

The implant: It’s a plastic tube the size of a matchstick that slowly releases an anti-HIV drug. It would be placed under the skin of the arm.

HIV prevention: Even if you don't have the virus, taking anti-HIV drugs daily can stop you from getting infected. Such "pre-exposure prophylaxis," or PrEP, is for people at high risk of getting the virus, according to the Centers for Disease Control and Prevention. 

Set and forget: The idea behind the implant is that it would make PrEP easier. Because it would release an antiviral drug little by little over months, people would not have to remember to swallow pills. It’s based on a similar implant for birth control.

The evidence: The device is being developed by Merck, which carried out a three-month-long preliminary test in just 12 men. It contains an experimental, but long-acting, anti-HIV drug called islatravir. The company presented the prototype today at an HIV science conference in Mexico City. 

Downsides: Without having to fear the HIV virus, people on PrEP drugs might end up getting other sexually transmitted diseases, like chlamydia and gonorrhea, more often. That was the finding of a study published this April on 4,375 gay and bisexual men in Australia.