Back of matchbook scientists ?
In 2020 there was no defense. New England was smashed, meaning the old folks there. 1000s of Covid dead per day.
It is not a natural virus. It is unnatural, so there is no such thing as natural immunity, but there is recovered immunity after infection and recovery. Like vax, it doesn’t last long.
By the time northern hemisphere winter approaches the population’s immunity will be zero and so will all mitigation procedures like distancing. Lots of reservoirs out there for this winter. Taiwan is experiencing more Covid deaths per day right now than any time the last two years.