Sanna Giuseppina, Marongiu Alessandra, Firinu Davide, Piras Cristina, Franci Gianluigi, Galdiero Massimiliano, Pala Giuseppe, Palmas Vanessa, Angius Fabrizio, Littera Roberto, Perra Andrea, Orrù Germano, Campagna Marcello, Costanzo Giulia, Meloni Federico, Coghe Ferdinando, Chessa Luchino, Manzin Aldo
Microbiology and Virology Unit, Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy.
Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy.
Vaccines (Basel). 2022 Mar 29;10(4):531. doi: 10.3390/vaccines10040531.
Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, has caused over 460 million cases of infection and over 6 million deaths worldwide. The pandemic has called for science, technology, and innovation to provide solutions and, due to an incredible scientific and financial global effort, several prophylactic and therapeutic apparatuses such as monoclonal antibodies and vaccines were developed in less than one year to address this emergency. After SARS-CoV-2 infection, serum neutralizing antibodies are produced by B cells and studies on virus-neutralizing antibodies' kinetics are pivotal. The process of protective immunity and the duration of this kind of protection against COVID-19 remain to be clarified. We tested 136 sera from 3 groups of individuals, some of them providing multiple sequential sera (1-healthy, no previous CoV2-infected, vaccinated; 2-healthy, previous CoV2 infected, vaccinated; 3-healed, previous CoV2-infected, not vaccinated) to assess the kinetics of antibodies (Abs) neutralizing activity. We found that SARS-CoV-2 infection elicits moderate neutralizing antibody activity in most individuals; neither age nor gender appear to have any influence on Abs responses. The BNT162b2 vaccine, when administered in two doses, induces high antibodies titre endowed with potent neutralizing activity against bare SARS-CoV-2 in in vitro neutralizing assay. The residual neutralization capability and the kinetic of waning immunity were also evaluated over 9 months after the second dose in a reference group of subjects. Neutralization titre showed a decline in all subjects and the median level of S-protein IgG, over 270 days after the second vaccination dose, was below 10 AU/mL in 53% of serum tested.
严重急性呼吸综合征相关冠状病毒2（SARS-CoV-2）是新冠病毒病（COVID-19）的病原体，已在全球造成超过4.6亿例感染和超过600万人死亡。这场大流行促使科学、技术和创新提供解决方案，由于全球在科学和资金方面做出了巨大努力，在不到一年的时间里开发了几种预防和治疗手段，如单克隆抗体和疫苗，以应对这一紧急情况。SARS-CoV-2感染后，血清中和抗体由B细胞产生，对病毒中和抗体动力学的研究至关重要。保护性免疫的过程以及这种针对COVID-19的保护持续时间仍有待阐明。我们检测了来自3组个体的136份血清，其中一些个体提供了多个连续血清样本（1组-健康，既往未感染过新冠病毒且接种过疫苗；2组-健康，既往感染过新冠病毒且接种过疫苗；3组-康复，既往感染过新冠病毒且未接种过疫苗），以评估抗体（Abs）中和活性的动力学。我们发现，SARS-CoV-2感染在大多数个体中引发中等程度的中和抗体活性；年龄和性别似乎对抗体反应均无任何影响。BNT162b2疫苗在接种两剂时，在体外中和试验中可诱导产生高抗体滴度，对裸露的SARS-CoV-2具有强大的中和活性。在一组参考受试者中，还在第二剂接种后9个月内评估了残余中和能力和免疫减弱动力学。中和滴度在所有受试者中均呈下降趋势，在第二次接种疫苗剂量270多天后，53%的检测血清中S蛋白IgG的中位数水平低于10 AU/mL。
