Today, antiviral medications can turn HIV, a once fatal infection, into a chronic condition. Nonetheless, the cocktail of pills remains out of reach for many—and lapses in the daily regimen make them less effective. Wesley Sundquist, a biochemist at University of Utah, and Tomas Cihlar, a virologist at Gilead, a biopharmaceutical company, have labored for more than a dozen years to turn one antiviral treatment, lenacapavir, into a twice-a-year therapy to prevent HIV infection in those at high risk. Sundquist laid the groundwork in studying one of HIV’s proteins, the capsid, which creates a protective shell around the virus’ genome; Cihlar visited his labs and was impressed enough to take his discoveries to Gilead. There, his team found ways to extend the effect of the drug over six months, meaning infected patients only receive two injections a year to treat HIV. Researchers are now studying lenacapavir in people who are not HIV positive but are at high risk of exposure. If approved, it would be the first twice-a-year injected drug to prevent HIV. Early results show great promise.
Park is a TIME senior correspondent