John Wherry of the Perelman School of Medicine said the COVID-19 booster shot is safe for those with hybrid immunity, which occurs when someone who has already had the virus gets vaccinated. However, he said, hybrid immunity is already powerful on its own.
https://www.npr.org/sections/health-shots/2021/11/24/1058743263/im-fully-vaccinated-and-i-also-had-covid-do-i-need-a-booster NPR