Abstract
Objectives: To measure SARS-CoV-2 neutralizing antibody (NtAb) titres in previously infected or uninfected health care workers who received one or two doses of BNT162b2 mRNA COVID-19 vaccine.
Methods: NtAbs were titrated as dose-inhibiting 50% virus replication (ID 50 ) by live virus microneutralization. We evaluated 41 health care workers recovering from mild or asymptomatic infection at first vaccination dose (T1_inf) and 21 days later (T2_inf). Sixteen uninfected health care workers were evaluated 20 days after first dose (T2_uninf) and 20 days after second vaccine dose (T3_uninf).
Results: At T2_inf, but not at T1_inf, there was a significant correlation between days from diagnosis (median 313, interquartile range 285-322) and NtAb levels (P = 0.011). NtAb titres increased at T2_inf with respect to T1_inf (1544 (732-2232) vs 26 (10-88), P < 0.001). Similarly, there was a significant increase in NtAb titres at T3_uninf compared with T2_uninf (183 (111-301) vs 5 (5-15), P < 0001). However, NtAb levels at T2_inf were significantly higher than those at T2_uninf and T3_uninf (P < 0.0001 for both analyses).
Conclusions: A single vaccination in people with mild or asymptomatic previous infection further boosts SARS-CoV-2 humoral immunity to levels higher than those obtained by complete two-vaccination in uninfected subjects.
Keywords: BNT162b2 mRNA COVID-19 vaccine; Health care workers; Neutralizing antibody response.
【저자키워드】 health care workers, Neutralizing antibody response, BNT162b2 mRNA COVID-19 vaccine, 【초록키워드】 COVID-19, SARS-CoV-2, COVID-19 vaccine, Health care, Antibody Response, Infection, Diagnosis, vaccine dose, Humoral immunity, Asymptomatic, mRNA, asymptomatic infection, Health care worker, Mild, virus replication, correlation, boost, Live virus, SARS-CoV-2 neutralizing antibody, BNT162b2 mRNA, microneutralization, dose, interquartile range, significant increase, first dose, titre, first vaccination, single vaccination, uninfected, Complete, evaluated, median, subjects, significantly higher, analyses, of BNT162b2, 【제목키워드】 COVID-19 vaccine, SARS-COV-2 infection, Asymptomatic, Health care worker, Mild, Neutralizing antibody response, boost, BNT162b2 mRNA, Single-dose, significantly,