Researchers Find Covid Survivors Have Long-Lasting Immunity to Re-Infection
timesofsandiego.com
timesofsandiego.com
""" While immune memory is the source of long-term protective immunity, direct conclusions about protective immunity cannot be made on the basis of quantifying SARS-CoV-2 circulating antibodies, memory B cells, CD8+ T cells, and CD4+ T cells, because mechanisms of protective immunity against SARS-CoV-2 or COVID-19 are not defined in humans. """ (https://science.sciencemag.org/content/early/2021/01/06/scie... also linked in the article)
Can someone clarify what protective immunity is ?