John Hollis didn’t realise he’d been infected with Covid-19. But he later discovered he’s one of the rare people who has “super antibodies”.
The antibodies are so good at killing the virus, he’s practically immune to the disease.
Still, if scientists hope to find others like John, they’ll have to tackle long standing mistrust among the African-American community.
Produced by the BBC’s Chelsea Bailey and Rod Macleod.