The Persistence of Natural SARS-CoV-2 Antibodies 12 Months Post COVID-19, a Prospective Cohort Study.

Abstract Background: It is unknown how long SARS-CoV-2 antibodies persist after COVID-19. The natural course of anti-SARS-CoV-2 antibodies was analyzed in a large post-COVID-19 cohort, until 12 months post-infection. Methods: The total antibodies SARS-CoV-2 (IgM and IgG) were tested in a cohort of patients with different COVID-19 disease severity sampled at 4 timepoints up to 12 months post COVID-19. In 23 randomly selected patients, the antibody isotypes: anti-spike IgM, IgA and IgG and anti-nucleocapsid IgG were analysed. Results: In total 152/153 patients (99%) tested positive for total anti-SARS-CoV-2 after 12 months of COVID-19; 3 patients tested positive at 8 to 10 months post infection just before vaccination. The SARS-CoV-2 antibody subclasses anti-nucleocapsid IgG, anti-spike IgG and IgA were all still detectable after 12 months. Anti-spike IgM waned after 12 months in the majority of patients.Conclusion: IgG and IgA antibodies against SARS-CoV-2 persisted 12 months post-COVID-19.