Rapid Decay of Anti–SARS CoV 2 Antibodies in Persons with Mild Covid 19

Among 34 volunteers who had recovered from mild Covid-19 illness, antiviral antibodies to the receptor-binding domain of the viral spike protein declined with a mean half-life of approximately 36 days after recovery. Whether these results predict the duration of viral immunity in persons recovering from more severe cases of Covid-19 or those exposed to vaccines is unknown.