Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15-30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3-4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4(+) or CD8(+) T cell responses 3-4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3-4 months after infection. Understanding if lasting immune responses can be induced by SARS-CoV-2 infection is important for controlling the COVID-19 pandemic. Here, the authors show, in a cohort of 25 patients, that IgG and T cell responses, as well as neutralising antibody, are still detectable against various SARS-CoV-2 proteins 3 months post-symptom onset, while IgM levels largely wane at this time.

Automated summary

The majority of SARS-CoV-2-infected patients maintain IgG, neutralising antibody, and T cell responses for at least 3-4 months post-infection, while IgM levels largely decrease during this time period.