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

This correspondence briefly describes results of observational research (n=34) that estimated the half-life of IgG antibodies against SARS-CoV-2 to be 36 days. The authors say their results raise concern humoral immunity may not be long-lasting in those with mild illness.

SPS commentary:

The last measurement in this study was obtained after a median of 86 days after the onset of symptoms, and they note that it is difficult to extrapolate their findings beyond this period as it is likely the decay will decelerate. However they say their findings “call for caution regarding antibody-based “immunity passports,” herd immunity, and perhaps vaccine durability, especially in light of short-lived immunity against common human coronaviruses. Further studies will be needed to define a quantitative protection threshold and rate of decline of antiviral antibodies beyond 90 days.”


New England Journal of Medicine