Quick Summary<p>SARS(v1) (2003 now died out) still shows memory T cells 17 years later with no additional exposures.<p>SARS(v1) T cells show robust cross-reactivity with the N protein of SARS-Cov-2 i.e. good chance of immunity to SARS-Cov-2.<p>Additionally some people no exposure to SARS(v1) or SARS-Cov-2 have SARS-Cov-2 memory T-Cells present possible expoure to Beta-Cov viruses from animals.<p>These people also have low homology to the common cold viruses.<p>The outlook is good for immunity being remembered for a long period of time and will be valid against other forms of Betacovid viruses. Best news I've heard in a long time.<p>(edit layout)