Derek Lowe's blog (linked by jhayward, thanks) has a good rundown of the recent T Cell research and what it means in general: https://blogs.sciencemag.org/pipel

Derek Lowe's blog (linked by jhayward, thanks) has a good rundown of the recent T Cell research and what it means in general: https://blogs.sciencemag.org/pipeline/archives/2020/07/15/new-data-on-t-cells-and-the-coronavirus https://blogs.sciencemag.org/pipeline/archives/2020/07/15/ne... But, he (and the paper authors!) seem to skim right over what might be the most important conclusion: > Recognition of the nsp7 and nsp13 proteins is prominent, ~as well as the N protein~. And when they looked at that nsp7 response, it turns out that the T cells are recognizing particular protein regions that have low homology to those found in the “common cold” coronaviruses – but do have very high homology to various animal coronaviruses. This "NP" or "nucleocapsid protein" has high homology to "common cold" human betacoronaviruses (OC43 and HKU1), so this basically means that previous exposure to these colds should confer some degree of immunity to SARS-CoV-2. The novel result that everyone seems to be dwelling on is interesting too, it raises the possibility that coronaviruses are transmitted from animals to humans more often than had been previously thought.