This 21-year-old thought he had overcome a mild case of Covid-19. Then he went into organ failure - CNN

"I never thought, at 21, I would be on the verge of death," he said.

Initially, the infection seemed just like the flu or a cold, he said, and the symptoms lasted for a few days.

"About a week and a half, two weeks later, I started feeling bad," he said.

While many seem to go through the infection without symptoms, there's still no telling how each individual will react to the virus.

Rollyson said doctors told him his body went into hyperactive mode trying to fight off coronavirus before he suffered heart failure, acute respiratory failure and severe sepsis.