This isn't common knowledge. This is something people (non-experts) are starting to infer, because we're seeing it with Long COVID - https://news.ycombinator.com/item?id=48877214 - but there's no reason to think this is something special about SARS-CoV-2 - it could just as well happen with all viral infections but we weren't looking.
It reminds me that we didn't look at vaccine efficacy at the individual level until SARS-CoV-2. People were getting upset that SARS-CoV-2 vaccines only have a moderate chance to stop you getting the virus, and usually lessen its impact if you do get it, and calling this an ineffective vaccine. But the truth is, we have no idea whether every previous vaccine was also like that, because we only ever looked at the population level: when lots of people get the vaccine, the virus dies out.
It reminds me that we didn't look at vaccine efficacy at the individual level until SARS-CoV-2. People were getting upset that SARS-CoV-2 vaccines only have a moderate chance to stop you getting the virus, and usually lessen its impact if you do get it, and calling this an ineffective vaccine. But the truth is, we have no idea whether every previous vaccine was also like that, because we only ever looked at the population level: when lots of people get the vaccine, the virus dies out.