NEJM STUDY — Covid survivors with natural immunity at low risk for reinfection or severe symptoms
“…In earlier studies, we assessed the efficacy of previous natural infection as protection against reinfection with SARS-CoV-22,3 as being 85% or greater. Accordingly, for a person who has already had a primary infection, the risk of having a severe reinfection is only approximately 1% of the risk of a previously uninfected person having a severe primary infection. It needs to be determined whether such protection against severe disease at reinfection lasts for a longer period, analogous to the immunity that develops against other seasonal “common-cold” coronaviruses,4 which elicit short-term immunity against mild reinfection but longer-term immunity against more severe illness with reinfection. If this were the case with SARS-CoV-2, the virus (or at least the variants studied to date) could adopt a more benign pattern of infection when it becomes endemic…”