Yeztugo, approved by the FDA, was highly effective in two randomized trials. It costs $28,218 per year, and people have to be HIV-negative to get it.

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.

A new twice-yearly shot could be a "game changer" in the fight against AIDS, but experts' hopes have dimmed because of the current political climate.