> Where are you getting your info from?
I am not insisting on that, but several people in my community had a second sickness seriously harder than first . It may be that Jewish community was hit early, so with passing of time and change in variants, maybe some become vulnerable again, and will be again with new variant coming.
Actually, a fresh Lancet article from Britain talks about this: Reinfection with new variants of SARS-CoV-2 after natural infection, Dec 2021 says that re-infection was 8x less likely than new infection in nursing homes between spring 2020 and Jan 2021. Most importantly, it says that those who will re-infect all had low antibody levels.
So, the right thing to do seems to be at least measure antibodies. Previous advice I saw was to get at least one vaccine dose.