Abstract
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.
【초록키워드】 SARS-CoV-2, Vaccine, SARS-COV-2 infection, Sex, immune system, immunization, cohort study, immunoassay, AZD1222, COVID-19 infection, Factors, age, development, natural immunity, significant difference, subject, dosage, study period, asthma patients, transmission of SARS-CoV-2, Prevent, NAb titer, was used, significantly, median, subjects, effective vaccine, retained, clinical implication, dropped, 【제목키워드】 neutralizing antibody, SARS-CoV-2, persistence, immunized,