WASHINGTON — The U.S. has approved the world’s only twice-a-year shot to prevent HIV, the first step in an anticipated global rollout that could protect millions – although it’s unclear how many in the U.S. and abroad will get access to the powerful new option.

Gilead Sciences has received US FDA approval for Yeztugo, its bi-annual HIV prevention injection, which has shown 96 per cent effectiveness in trials. Here's how it works, and what it costs.

Gilead's CEO says he's committed to making sure people around the world can get his firm's new HIV prevention shot Yeztugo.