Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ( $$ \overline{x} $$ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

中文翻译：

---

INT – IRCCS“ Fondazione Pascale”癌症中心（意大利那不勒斯）的医护人员的疫苗接种策略和抗SARS-CoV-2 S滴度

严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）感染以及由此引发的疾病-冠状病毒病2019（COVID-19）已在全球蔓延至数百万人，需要开发数十亿种不同剂量的疫苗。由FDA授权的SARS-CoV-2加标mRNA疫苗（命名为BNT162b2 / Pfizer）在16岁及16岁以上的个人服用两剂后已显示出有效预防SARS-CoV-2感染的功效。在本研究中，我们回顾性分析了INTCS的IRCCS“ Fondazione Pascale”癌症中心（意大利那不勒斯）以前两个感染人群的疫苗接种后SARS-CoV-2体液免疫反应的差异： SARS-CoV-2受试者，未感染SARS-CoV-2受试者。我们通过Roche Elecsys Anti-SARS-CoV-2 S免疫测定法对35位具有先前记录的历史的医护人员的血清样品中的SARS-CoV-2三聚体糖蛋白（S）的特异性抗RBD（受体结合域）滴度进行了测定在分别接种1剂和2剂疫苗后，分别感染了SARS-CoV-2病毒和158名医护人员。此外，计算了几何平均滴度和相对倍数变化（FC）。分别感染1剂和2剂疫苗后，先前感染SARS-CoV-2的受试者和未感染SARS-CoV-2的受试者均对SARS-CoV-2产生了明显的免疫反应。与之前和之后接种第一剂和第二剂疫苗的未感染受试者的滴度相比，先前感染SARS-CoV-2的受试者对第一剂疫苗的抗S抗体应答显着更高。鉴于基础抗体滴度高以及Roche方法施加的2500.0 BAU / mL的上限，先前感染SARS-CoV-2的受试者的倍数变化非常适度。相反，对于未接受治疗的受试者，第一次给药后的平均倍数变化较低（$ \ overline {x} $$ = 1.6），在第二次给药后的72位受试者（4.5.6％）达到3.8 FC。结果表明，与先前未感染病毒的人相比，最早感染第一剂的SARS-CoV-2感染者产生了显着且统计学上显着的免疫反应，这表明以前仅可接种一剂的可能性。 SARS-CoV-2感染的受试者。总体而言，疫苗接种前的值通常较高，因此不应考虑先前感染受试者的FC。相反，对于未感染的受试者，FC