Objective To follow serological immune responses of front-line healthcare workers after PCR-confirmed COVID-19 for a mean of 30 weeks, describe the time-course of SARS-CoV-2 spike protein-specific IgG, IgA and IgM levels and to identify associations of the immune response with symptoms, demographic parameters and severity of disease. Methods Anti-SARS-CoV-2 S protein-specific IgG, IgA and IgM antibodies were measured at three time points during the 30-week follow-up. COVID-19-specific symptoms were assessed with standardized questionnaires. Results 95% of the participants mounted an IgG response with only modest decline after week 12. IgG-type antibodies were still detectable in almost 90% of the subjects at 30 weeks. IgA and IgM responses were less robust and antibody titers decreased more rapidly. At 30 weeks, only 25% still had detectable IgA-type and none had IgM-type antibodies. Higher age and higher disease severity were independently associated with higher IgG antibody levels, albeit with wide variations. Conclusion Serological immune responses after COVID-19 show considerable inter-individual variability, but show an association with increasing age and higher severity of disease. IgG-type anti-SARS-CoV-2 antibodies remain positive in 90% of the individuals 30 weeks after onset of symptoms. Supplementary Information The online version contains supplementary material available at 10.1007/s15010-021-01598-6.
【저자키워드】 COVID-19, SARS-CoV-2, ELISA, Antibody titer, Serological immune response, Severity of disease, 【초록키워드】 antibodies, IgG, IgM, immune response, S protein, antibody, disease severity, Symptom, anti-SARS-CoV-2, Symptoms, healthcare worker, Spike protein, IgG antibody, anti-SARS-CoV-2 antibody, IgM antibodies, IgA, immune responses, SARS-CoV-2 spike protein, age, Follow-up, variations, serological, Antibody titers, SARS-CoV-2 spike, association, IgG response, Questionnaires, supplementary material, IgM responses, subject, IgM antibody, individual, Variability, participant, increasing age, PCR-confirmed COVID-19, positive, IgM response, parameter, objective, robust, Result, identify, detectable, less, onset of symptoms, were measured, inter-individual, mounted, were assessed, 【제목키워드】 antibody, Moderate COVID-19, Cohort, Mild,