Purpose To compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.1.617.2 variants-of-concern, in subjects with different Covid-19 disease and vaccination histories. Methods Adult subjects were: 1) Unvaccinated/hospitalized for Covid-19; 2) Covid-19-recovered followed by one BNT162b2 vaccine dose; and 3) Covid-19-naïve/2-dose BNT162b2 vaccinated. Multiplex Luminex ® immunoassays measured IgG, IgA, and IgM plasma levels against SARS-CoV-2 receptor-binding domain (RBD), spike-1 (S), and nucleocapsid proteins. Neutralizing activity was determined in Vero E6 cytopathic assays. Results Maximum anti-RBD IgG levels were similar in Covid – 19‑recovered individuals 8‒10 days after single-dose vaccination and in Covid-19-naïve subjects 7 days after 2 nd vaccine dosing; both groups had ≈2‑fold higher anti-RBD IgG levels than Unvaccinated/Covid-19 subjects tracked through 2 weeks post-symptom onset. Anti-S IgG expression patterns were similar to RBD within each group, but with lower signal strengths. Viral antigen-specific IgA and IgM levels were more variable than IgG patterns. Anti-nucleocapsid immunoglobulins were not detected in Covid-19-naïve subjects. Neutralizing activity against the B.1 strain, and Gamma/P.1 and Delta/B.1.617.2 variants, was highest in Covid‑19-recovered/single-dose vaccinated subjects; although neutralization against the Delta variant in this group was only 26% compared to B.1 neutralization, absolute anti-Delta titers suggested maintained protection. Neutralizing titers against the Gamma and Delta variants were 33‒77% and 26‒67%, respectively, versus neutralization against the B.1 strain (100%) in the three groups. Conclusion These findings support SARS-CoV-2 mRNA vaccine usefulness regardless of Covid-19 history, and confirm remarkable protection provided by a single vaccine dose in people who have recovered from Covid-19.
【저자키워드】 COVID-19, SARS-CoV-2, coronavirus, Serological assay, Neutralization assay, Fluorescence, multiplex immunoassay, bead, 【초록키워드】 IgG, IgM, Vaccine, BNT162b2 vaccine, vaccination, mRNA vaccine, neutralization, immunoglobulins, delta variant, variants, COVID-19 disease, COVID‐19, BNT162b2, immunoassay, Neutralizing activity, Viral, Immunoglobulin, RBD, IgA, Gamma, plasma, neutralizing capacity, SARS-CoV-2 antigen, disease, Delta variants, dose, B.1, anti-RBD, Vero E6, Anti-RBD IgG, followed by, Support, symptom onset, Viral antigen, both groups, subject, individual, post-symptom onset, domain, IgG levels, naïve, Nucleocapsid proteins, three groups, maximum, neutralizing titers, expression pattern, single vaccine, antigen-specific antibody, cytopathic, Result, highest, assays, provided, was determined, subjects, suggested, both group, 【제목키워드】 activity, history, Against,