No, not including after vaccination. When people speak about pre-existing immunity, it's most of the time covid deniers saying there "natural" immunity and vaccines are useless or harmful.
(Of course there is also valid discussion of pre-existing immunity, but the more nuanced messages are not as common.)
Vaccine advocates like yourself can never explain why infection doesn't imply immunity while vaccines do.
Sinovac, the Chinese vaccine, is only 50% effective. Pfizer and Moderna are much more effective. J&J is somewhere in between. This is widely accepted but no one seems to ever ask: if I was sick a month ago, where does it fall in that scale?
The point of vaccines is to give your immune system a good enough idea of the pathogen, so that your body produces antibodies. Actually contracting the disease does the same thing, unsurprisingly.
So the question is how effective is natural infection of COVID-19 at preventing future infection? Surely it's better than Sinovac, a coin flip. No? Do you have any scholarship about this I can look at?
