Clinical trials have shown that six-monthly injections of lenacapavir are almost 100 percent protective against becoming infected with HIV. But big questions remain over the drug’s affordability.

The FDA approved Gilead's HIV prevention drug lenacapavir, a twice-a-year injectable medication that clinical trials show prevents new infections.

The drug could change the course of the AIDS epidemic. But the Trump administration has gutted the programs that might have paid for it in low-income countries.