Molecular Pathology Laboratory, Institute of Biological Sciences, University of Rajshahi, Rajshahi, 6205, Bangladesh.
Department of Population Science and Human Resource Development, University of Rajshahi, Rajshahi, 6205, Bangladesh.
Sci Rep. 2022 Aug 29;12(1):14681. doi: 10.1038/s41598-022-18302-9.
Development of effective vaccines have been immensely welcomed by the world to prevent the transmission of SARS-CoV-2. However, the duration and clinical implications of antibody-mediated natural immunity in SARS-CoV-2 have not been adequately elucidated alongside some other immune system transforming factors. In a cohort study, we measured NAb titer following the 2nd immunization dosage of the CoviShield (AZD1222) vaccine. The enzyme-linked immunoassay was used to look for SARS-CoV-2-specific NAb. We measured NAb at 30 days after the 2nd dosage of immunization and > 96% titer was detected in 42.9% of subjects, but only 5.1% of subjects retained the same level after 180 days. The median NAb titer dropped significantly, from 92% at 30 days to 58% at 180 days (p < 0.001). Besides, there were significant differences observed in NAb titer after 180 days by age, sex, COVID-19 infection, tobacco use, and asthma patients. However, SARS-CoV-2 infection along with two dosages of immunization upheld NAb titer (p < 0.001) even at the end of the study period.
开发有效的疫苗已受到全球的热烈欢迎，以预防 SARS-CoV-2 的传播。然而，SARS-CoV-2 中抗体介导的自然免疫的持续时间和临床意义，以及一些其他免疫系统转化因素，尚未得到充分阐明。在一项队列研究中，我们在接种第二剂科维希尔德（AZD1222）疫苗后测量了中和抗体滴度。酶联免疫吸附试验用于寻找 SARS-CoV-2 特异性中和抗体。我们在接种第二剂后 30 天测量中和抗体，在 42.9%的受试者中检测到超过 96%的滴度，但在 180 天后只有 5.1%的受试者保留相同水平。中和抗体滴度显著下降，从第 30 天的 92%下降到第 180 天的 58%（p<0.001）。此外，在 180 天后，年龄、性别、COVID-19 感染、吸烟和哮喘患者的中和抗体滴度存在显著差异。然而，SARS-CoV-2 感染和两剂免疫接种维持了中和抗体滴度（p<0.001），即使在研究结束时也是如此。
