Singer Billie Eilish has revealed she faced a nightmare of being infected with COVID-19 over the summer and believes she "would have died" if she had not been vaccinated.

"When I say it was bad, I mean I felt terribly bad. But realistically, I think the vaccine helped me a lot.

Eilish said she is still experiencing long-term symptoms of COVID.

"I did not die, but it still left some traces on me. "It was terrible," said Eilish. "I still have side effects. "I was sick for almost two months."

Her diagnosis came after she released her latest album, "Happier than Ever," in late July.