The Antibody Response and SARS-CoV-2 Infection, How Long does it Last?
A preprint published by Jeffrey Seow and other suggests that the antibody response to SARS-CoV-2 can be detected in most infected individuals 10 to 15 days following the onset of COVID-19 symptoms. Unfortunately, it is still not yet known how long these antibody responses are maintained for or whether they will provide protection from re-infection.
The authors used sequential serum samples collected up to 94 days post onset of symptoms from 65 PCR confirmed SARS-CoV-2-infected individuals.
They showed seroconversion in more than 95% of cases and a neutralising antibody response when sampled beyond eight days post onset of symptoms.
They demonstrated that the magnitude of the antibody response is dependent upon the disease severity. However, this did not affect the kinetics of the antibody response. They noted declining antibody titres during the follow up period.
Whilst some individuals with a very high peak maintained titres greater than 1,000 at more than 60 days post onset of symptoms, others with a lower peak had titres approaching baseline within the follow-up period.
A similar decline in antibody titres was also observed in a cohort of seropositive healthcare workers from Guy′s and St Thomas′ Hospital.
The authors suggest that this transient antibody response is a feature shared by both a SARS-CoV-2 infection that causes low disease severity and the circulating seasonal coronaviruses that are associated with common colds.
The authors suggest that their study has important implications when considering widespread serological testing, antibody protection against re-infection with SARS-CoV-2 and the durability of vaccine protection.