Abstract
Background: Studies evaluating neutralizing antibody (NAb) after BNT162b2 vaccine are scarce. We therefore compared NAb using the plaque reduction neutralization test (PRNT) in vaccinated subjects, with those from five chemiluminescent (CLIA) assays, two targeting ACE and S-RBD interaction.
Methods: Sera from 174 completely Comirnaty/BNT162b2 vaccinated healthcare workers (HCW) were evaluated at t 12 and t 28 . NAb titers at low (PRNT 50 ) or high (PRNT 90 ) stringency were compared with: Liaison SARS-CoV-2 Trimeric-S IgG, Elecsys S-RBD Ab, Maglumi SARS-CoV-2 S-RBD IgG and SARS-CoV-2 Nab; iFlash 2019-nCoV NAb.
Results: Neither PRNT 50 nor PRNT 90 correlated with age (range, 24-65 years); no significant differences were found for gender. PRNT 50 and PRNT 90 seropositive titers (≥1:20) were 43 (24.7%) and 15 (8.6%) at t 12 and 167 (95.9%) and 149 (85.6%) at t 28 . CLIA results at t 28 were uncorrelated with age, apart from Elecsys S-RBD Ab (r = -0.164, p = 0.046). Gender differences were found for Maglumi SARS-CoV-2 S-RBD IgG (p = 0.037) and Maglumi NAb (p = 0.046). Considering PRNT 50 at thresholds of 1:20 (or 1:40) and 1:160 (or 1:320), corresponding to different immune protective levels, CLIA cut-offs have been identified.
Conclusions: Comirnaty/BNT162b2 elicits strong NAb production, especially 28 days after first inoculum. Differences in correlation between Nab titers and circulating antibodies measured by 5 immunoassays have been found, being stronger the correlation for Maglumi Nab.
Keywords: Antibody; BNT162b2; COVID-19; Comirnaty; Immunoassays; Immunological response; SARS-CoV-2 vaccine; Serology.
【저자키워드】 COVID-19, serology, antibody, SARS-CoV-2 vaccine, BNT162b2, immunoassays, Comirnaty, Immunological response, 【초록키워드】 neutralizing antibody, CLIA, SARS-CoV-2, IgG, BNT162b2 vaccine, 2019-nCoV, Gender, healthcare worker, immune, immunoassay, S-RBD, age, correlation, threshold, seropositive, PRNT, Protective, Interaction, ACE, HCW, circulating antibody, no significant difference, cut-off, plaque reduction neutralization, FIVE, difference, NAb titer, assays, evaluated, subjects, correlated, elicit, Elecsy, 【제목키워드】 Kinetics, SARS-CoV-2 neutralizing antibody, Chemiluminescent assay, dose,