Abstract
Background: The kinetics of the antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated since long-term duration of antibody remains largely unknown, particularly in infected healthcare workers (HCW).
Methods: Prospective study, evaluating the longitudinal profile of anti-SARS-CoV-2 antibody titers in a random sample of 331 seropositive healthcare workers (HCW) of Spanish Hospitals Group. Serial measurements of serum IgG-anti-SARS-CoV-2 were obtained at baseline (April-May,2020), and in 2 follow-up visits. Linear mixed models were used to investigate antibody kinetics and associated factors.
Results: A total of 306 seropositive subjects (median age: 44.7years;69.9% female) were included in the final analysis. After a median follow-up of 274 days between baseline and final measurement, 235(76.8%) maintained seropositivity. Antibody titers decreased in 82.0%, while remained stable in 13.1%. Factors associated with stability of antibodies over time included age≥45 years, higher baseline titers, severe/moderate infection and high-grade exposure to COVID-19 patients. In declining profile, estimated mean antibody half-life was 146.3 days(95%CI:138.6-154.9) from baseline. Multivariate models show independent longer durability of antibodies in HCW with high-risk exposure to COVID-19 patients (+14.1 days;95%CI:0.6-40.2) and with symptomatic COVID-19 (+14.1 days;95%CI:0.9-43.0). The estimated mean time to loss antibodies was 375(95% CI:342-408) days from baseline.
Conclusions: We present the first study measuring the kinetics of antibody response against SARS-CoV-2 in HCW beyond 6 months. Most participants remained seropositive after 9 months but presented a significant decline in antibody-titers. Two distinct antibody dynamic profiles were observed (declining vs. stable). Independent factors associated with longer durability of antibodies were symptomatic infection and higher exposure to COVID-19 patients.
Keywords: Antibodies; Antibody kinetics; COVID-19; Durability; Healthcare Personnel; Healthcare Workers; Immune-response; Persistence; SARS-CoV-2.
【저자키워드】 COVID-19, antibodies, SARS-CoV-2, Healthcare workers, Immune-response, persistence, antibody kinetics, Durability, healthcare personnel, 【초록키워드】 SARS-CoV-2, coronavirus, antibody, Infection, healthcare worker, serum, stability, anti-SARS-CoV-2 antibody, symptomatic, Prospective, female, Factors, Follow-up, group, seropositive, COVID-19 patients, symptomatic infection, Analysis, COVID-19 patient, HCW, acute respiratory syndrome, Factor, profile, multivariate, participant, Final, random, follow-up visits, MOST, Spanish, independent, remained, evaluated, median, were used, antibody response against, baseline, declining, seropositive subject, the antibody, 【제목키워드】 anti-SARS-CoV-2 antibody, seropositive, worker, Result,