[shadowprofile77]

I really, really wish there could be a clear answer on at least this one basic thing that one would think (as a layman) to be fairly understood about viruses and immune response: Having had a SARS COVID 2 infection and assuming the virus hasn't mutated in the way that influenza does periodically to keep needing new vaccines, does or does not your body gain bloody immunity for some time after recovery? From everything I've know to date, the absolute normal, standard thing is that yes, being sick with something viral that doesn't cause your death gives you at least a certain period of months or usually years of immunity to it unless it mutates enough to re-attack without being recognized immediately. Is this not correct? For smallpox it applied, for chicken pox it does, for measles it mostly does for many years, likewise for many viruses for which there are vaccines. We even get immunity from the flu once we've had it for at least some months to a year or two. So why would Covid 2 be different?

[T-hawk]

Short answer: recovering from Covid-19 probably does give immunity, based on all the precedents you mention, but we can't prove it for sure yet because not enough time has elapsed and no sufficiently rigorous studies have been done.

Of course viral antibodies persist for some amount of time, they don't disappear immediately upon clearing the virus. What we don't know is anything about the shape of that persistence. Is it days or weeks or years? Does it decline linearly, or exponentially (as a half-life), or on some other schedule? What kind of variance between people is there? How much does it vary based on all the other factors, like other health and immunological conditions, or re-exposure to the virus? This is all what we don't know yet, but need to before we can make assumptions regarding herd immunity to start lifting lockdowns.