'The Centers for Disease Control and Prevention once advised five days of isolation after a positive Covid test, followed by five days of masking when out in public. That is still a reasonable approach, Dr. Barouch said. “It’s believed that after about five days, then contagiousness goes down substantially,” he said, though that “doesn’t necessarily mean every single person on day six would not be contagious.”'
https://www.nytimes.com/2024/07/18/well/covid-contagious-period.html