Immunological memory to SARS-CoV-۲ assessed for up to ۸ monthsafter infection

Immunological memory is the basis for durable protective immunity after infections orvaccinations. Duration of immunological memory after severe acute respiratory syndromecoronavirus ۲ (SARS-CoV-۲) infection and COVID-۱۹ is unclear. Immunological memory canconsist of memory B cells, antibodies, memory CD۴+ T cells, and/or memory CD۸+ T cells.Knowledge of the kinetics and interrelationships among those four types of memory in humans islimited. Understanding immune memory to SARS-CoV-۲ has implications for understandingprotective immunity against COVID-۱۹ and assessing the likely future course of the COVID-۱۹pandemic. Assessing virus-specific immune memory over at least a ۶-month period is likelynecessary to ascertain the durability of immune memory to SARS-CoV-۲. Given the evidencethat antibodies, CD۴+ T cells, and CD۸+ T cells can all participate in protective immunity toSARS-CoV-۲, we measured antigen-specific antibodies, memory B cells, CD۴+ T cells, andCD۸+ T cells in the blood from subjects who recovered from COVID-۱۹, up to ۸ months afterinfection.