Devi Leimapokpam Sumitra, Sardar Moumita, Sharma Mukesh, Khandait Manisha
Department of Microbiology, Faculty of Medicine and Health Sciences, SGT University, Gurugram, Haryana, India.
Int J Microbiol. 2022 May 31;2022:4729844. doi: 10.1155/2022/4729844. eCollection 2022.
An increase in COVID-19 immunization coverage has been linked to a decrease in the average case fatality rate. As a result, further research is needed to determine the persistence and duration of vaccine-induced protective antibodies in order to assess the effectiveness of COVID-19 vaccinations. The present study aimed to determine the COVID-19 IgG antibodies among healthcare workers (HCWs) before and after the ChAdOx1 nCoV-19 (Covishield™) vaccination. A total of 150 HCWs who had received the Covishield™ vaccine were assessed after obtaining written informed consent. Blood samples were drawn at three time points, namely, within one week prior to first dose of vaccination, prior to second dose of vaccination (28-33 days after the first dose of vaccination), and 90-95 days after the second dose of vaccination for detecting neutralizing antibodies, i.e., IgG antibodies by ELISA. The overall baseline seropositivity among the HCWs was found to be 28% ( = 42), assessed by the sample collected prior to first dose of COVID-19 vaccination. The seroconversion rate was reported to be 80% ( 120) one month after the first dosage and increased to 92.7% ( 139) three months later. Additionally, there was a significant gradual increase in the IgG concentrations postvaccination in majority of the study participants. In those HCWs who had prior history of SARS-CoV-2 infection, significantly higher antibody level was observed compared to antibody-naive individuals. Fever, pain or swelling at the site of injection, and headache were the most frequently reported adverse events following vaccination among the study participants. Regardless of prior SARS-CoV-2 positivity, two doses of the Covishield vaccine elicited a protective neutralizing antibody response that lasted for three months after the second dose of vaccination.
新冠病毒免疫接种覆盖率的提高与平均病死率的降低有关。因此，需要进一步研究以确定疫苗诱导的保护性抗体的持久性和持续时间，以便评估新冠疫苗的有效性。本研究旨在测定医护人员在接种ChAdOx1 nCoV-19（Covishield™）疫苗前后的新冠病毒IgG抗体。在获得书面知情同意后，对总共150名接种了Covishield™疫苗的医护人员进行了评估。在三个时间点采集血样，即第一剂疫苗接种前一周内、第二剂疫苗接种前（第一剂疫苗接种后28 - 33天）以及第二剂疫苗接种后90 - 95天，用于通过酶联免疫吸附测定法检测中和抗体，即IgG抗体。通过在首次接种新冠疫苗前采集的样本评估，医护人员的总体基线血清阳性率为28%（n = 42）。据报告，首次接种后一个月血清转化率为80%（n = 120），三个月后升至92.7%（n = 139）。此外，大多数研究参与者接种疫苗后IgG浓度显著逐渐升高。在那些有新冠病毒感染既往史的医护人员中，观察到的抗体水平明显高于未感染过的个体。发热、注射部位疼痛或肿胀以及头痛是研究参与者接种疫苗后最常报告的不良事件。无论之前新冠病毒检测结果是否为阳性，两剂Covishield疫苗均引发了保护性中和抗体反应，该反应在第二剂疫苗接种后持续了三个月。
