Humoral immunity after infection or after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been attributed a key part in mitigating the further transmission of the virus. In this study, we used a commercial anti-Spike immunoglobulin G (S-IgG) assay and developed a cell culture-based neutralization assay to understand the longitudinal course of neutralizing antibodies in both SARS-CoV2 infected or vaccinated individuals. We show that even more than one year after infection, about 78% of observed study participants remained seropositive concerning S-IgG antibodies. In addition, the serum of the individuals had stable neutralization capacity in a neutralization assay against a SARS-CoV-2 patient isolate from March 2020. We also examined volunteers after either homologous BNT162b2 prime-boost vaccination or heterologous AZD1222 prime/mRNA-based booster vaccination. Both the heterologous and the homologous vaccination regimens induced higher levels of neutralizing antibodies in healthy subjects when compared to subjects after a mild infection, showing the high effectiveness of available vaccines. In addition, we could demonstrate the reliability of S-IgG levels in predicting neutralization capacity, with 94.8% of seropositive samples showing a neutralization titer of ≥10, making it a viable yet cheap and easy-to-determine surrogate parameter for neutralization capacity.
【저자키워드】 COVID-19, antibodies, SARS-CoV-2, vaccination, Immunity, serology, neutralization, 【초록키워드】 neutralizing antibody, coronavirus, SARS-CoV2, reliability, Vaccines, Infection, Transmission, virus, BNT162b2, serum, AZD1222, Immunoglobulin, Neutralization assay, Patient, Effectiveness, homologous, seropositive, Heterologous, mild infection, booster vaccination, neutralization capacity, regimen, acute respiratory syndrome, subject, individual, vaccinated individuals, neutralization titer, parameter, Volunteer, Cell, Course, examined, addition, remained, concerning, healthy subject, study participant, seropositive sample, 【제목키워드】 Level, Year,