Immunity persists for a while but doesn’t seem to stop the new variants. Another study shows that re-infection with Covid is a lot more likely in unvaccinated people than in vaccinated.
> More than 7,700 new cases of the virus have been detected during the most recent wave starting in May, but just 72 of the confirmed cases were reported in people who were known to have been infected previously – that is, less than 1% of the new cases.
> Roughly 40% of new cases – or more than 3,000 patients – involved people who had been infected despite being vaccinated.
Optimistically both vaccine and natural immunity are good, but the numbers above seem to indicate that natural immunity is significantly better.
https://directorsblog.nih.gov/2021/06/22/how-immunity-genera...