I think it is well established that prior infection by COVID (even if asymptomatic) provides strong immune response to future infection.
One of the major vaccine candidates (I think Merck), scrapped their vaccine development, because they said that natural infection would provide stronger protection.
Agreed, Merck did release that statement, which is common knowledge regarding past infection and immunity. But, the info I received gave the impression this was not the case, and that people should just get the shots anyway. Crazy lies and Orwellian Double Speak.