Study of pre-existing antibodies to COVID in the Vancouver area:
"We determine that more than 90% of uninfected adults showed antibody reactivity against the spike, receptor-binding domain (RBD), N-terminal domains (NTD) or the nucleocapsid (N) protein from SARS-CoV-2."
If other regions are significantly less than 90%, that could explain a lot re: differences in covid case growth; Vancouver wasn't hit particularly hard.
@lucash_dev Well remember that reactivity doesn't mean you're totally immune. But it may reduce deaths and symptoms.
As for what is causing that, most likely other diseases. Lots of evidence that other coronavirus infections have a degree of cross immunity. Which yes, the very high asian population could be doing that. Be interesting to do the same tests in Toronto.