That number is just made up based on people who actually reported it. An actual study in UK indicated after 5 months, with slightly less than 1% of people who had been previously infected has caught it again after 5 months. This doesn't mean chance of catching is less than 1%, just that less than 1% of people in the study caught it again. The actual rate of being protected within 5 months is 83%The likelihood of spreading post-vaccine is probably going to be similar to the people who get Covid twice....it's a 1-in-100,000-1,000,000 people scenario. Doesn't mean the media won't scare you with it.
https://www.cnbc.com/2021/01/14/cov...round-as-much-immunity-as-vaccines-study.html