The woman, who identifies as mixed race, had both acute leukemia and HIV.

When Johan was born with a grave genetic illness called chronic granulomatous disease he benefited from a still experimental type of treatment known as T-cell therapy that helped his immune system fight off viruses after he received a...

New trials will start for a Chinese vaccine; another in the U.K. had good early results. They're two of more than 200 in development across the world.