Abstract
Objectives: This study aimed to assess kinetics and predictive variables of humoral immune response to mRNA SARS-CoV-2 vaccine administration.
Methods: We collected blood samples before (T0) and 15, 90, and 180 days after vaccination (T1, T2, and T3, respectively). The Quant SARS-CoV-2 Immunoglobulin (IgG) II Chemiluminescent Microparticle Immunoassay was used to determine anti-spike IgG.
Results: In almost 3000 healthcare-collected blood samples at the three time points, we found the following: at 15 days postvaccination, 97.6% of subjects presented a robust IgG anti-spike response (>4160 AU/ml); then, at three and six months, it decreased in median 6.5-fold to 35.0% and 3.0-fold to 3.3%, respectively. A linear mixed-effects model supported that female gender, younger age groups, and being seropositive prevaccination maintained higher antibody titers. Curves became tighter with time progression, although titers from seropositive subjects decrease at a slower rate than seronegative ones.
Conclusion: These findings strengthen the case for a steep decrease of anti-SARS-CoV-2 antibodies up to six months, suggesting that serological evaluation might guide the need for periodic booster vaccinations in specific groups prone to lower antibody titers.
Keywords: 6 months; Humoral immunity; Real-world data; SARS-CoV-2; mRNA vaccine.
【저자키워드】 SARS-CoV-2, real-world data, mRNA vaccine., Humoral immunity, 6 months, 【초록키워드】 IgG, vaccination, mRNA vaccine, progression, SARS-CoV-2 vaccine, anti-SARS-CoV-2 antibody, anti-Spike IgG, mRNA, age, humoral immune response, group, serological, seropositive, seronegative, Antibody titers, Anti-spike, booster vaccination, administration, Predictive, subject, blood sample, female gender, mixed-effects model, variable, postvaccination, decrease, robust, prevaccination, was used, collected, linear, supported, median, determine, groups, Curve, seropositive subject, 【제목키워드】 COVID-19, healthcare worker, mRNA, large cohort, serological, SARS-CoV-2 IgG,