Objectives

To assess the antibody response to BNT162b2 mRNA COVID-19 vaccine in a cohort of health-care workers (HCW), comparing individuals with previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and SARS-CoV-2-naive individuals.

Methods

HCW were tested at T0 (day of first dose), T1 (day of second dose) and T2 (2–3 weeks after second dose) for IgG anti-nucleocapsid protein, IgM anti-spike protein and IgG anti-receptor binding domain (IgG-RBD-S). The antibody response was compared between four main groups: group A, individuals with previous infection and positive antibodies at baseline; group B, individuals with the same history but negative antibodies; group C, individuals with no infection history but positive antibodies; group D, naive individuals. Repeated measures analysis was used to compare results over time-points.

Results

A total of 1935 HCW were included. Median IgG-RBD-S titre was significantly higher for group A (232 individuals) than for group B (56 individuals) both at T1 (A: 22 763 AU/mL, interquartile range (IQR) 14 222–37 204 AU/mL; B: 1373 AU/mL, IQR 783–3078 AU/mL, p 0.0003) and T2 (A: 30 765 AU/mL, IQR 19 841–42 813 AU/mL; B: 13 171 AU/mL, IQR 2324–22 688 AU/mL, p 0.0038) and for group D (1563 individuals; 796 AU/mL, IQR 379–1510 AU/mL at T1; 15 494 AU/mL, IQR 9122–23 916 AU/mL at T2, p < 0.0001 for both time-points). T1 values of group A were also significantly higher than T2 values of group D (p < 0.0001). Presence of symptoms, younger age and being female were associated with stronger antibody response. HCW infected in March showed a significantly stronger response (T1: 35 324 AU/mL, IQR 22 003–44 531 AU/mL; T2: 37 648 AU/mL, IQR 27 088–50 451 AU/mL) than those infected in November (T1: 18 499 AU/mL, IQR 11 492–27 283 AU/mL; T2: 23 210 AU/mL, IQR 18 074–36 086 AU/mL, p < 0.0001 for both time-points.

Conclusions

Individuals with past SARS-CoV-2 infection had a strong antibody response after one single vaccine shot. A single dose might be sufficient for this group, regardless of the time elapsed since infection; however, the clinical correlation with antibody response needs to be studied.

中文翻译：

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BNT162b2 mRNA COVID-19 疫苗在有或没有既往 SARS-CoV-2 感染的卫生保健工作者队列中诱导的抗体反应：一项前瞻性研究

目标

评估一组卫生保健工作者 (HCW) 对 BNT162b2 mRNA COVID-19 疫苗的抗体反应，比较先前感染严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 和未感染 SARS-CoV-2 的个体个人。

方法

HCW 在 T0（第一次给药的天数）、T1（第二次给药的天数）和 T2（第二次给药后 2-3 周）进行了 IgG 抗核衣壳蛋白、IgM 抗尖峰蛋白和 IgG 抗受体结合域的检测（ IgG-RBD-S)。比较了四个主要组之间的抗体反应：A 组，有既往感染史且基线抗体阳性的个体；B组，有相同病史但抗体阴性的个体；C组，无感染史但抗体阳性的个体；D组，天真的人。重复测量分析用于比较不同时间点的结果。

结果

共包括 1935 名 HCW。在 T1 时，A 组（232 个人）的中位 IgG-RBD-S 滴度显着高于 B 组（56 个人）（A：22 763 AU/mL，四分位距 (IQR) 14 222–37 204 AU/mL） ; B: 1373 AU/mL, IQR 783–3078 AU/mL, p 0.0003) 和 T2 (A: 30 765 AU/mL, IQR 19 841–42 813 AU/mL; B: 13 171 AU/mL, IQR 232 –22 688 AU/mL，p 0.0038）和 D 组（1563 个人；796 AU/mL，T1 时 IQR 379–1510 AU/mL；T2 时 15 494 AU/mL，IQR 9122–23 916 AU/mL，两个时间点的 p < 0.0001）。A 组的 T1 值也显着高于 D 组的 T2 值（p < 0.0001）。出现症状、年龄较小和是女性与更强的抗体反应有关。三月份感染的医护人员表现出明显更强的反应（T1：35 324 AU/mL，IQR 22 003–44 531 AU/mL；T2：37 648 AU/mL，

结论

曾经感染过 SARS-CoV-2 的人在注射一次疫苗后会产生强烈的抗体反应。无论感染后经过的时间如何，单次剂量对于该组可能就足够了；然而，需要研究与抗体反应的临床相关性。