NGHIÊN CỨU THỰC TRẠNG MIỄN DỊCH CỘNG ĐỒNG VỚI SARS -COV-2 TẠI THÀNH PHỐ HÀ NỘI

Abstract

Objectives: to assess the concentration of SARS-CoV-2 antibodies in the community and identify factors related to antibody levels. Subjects and methods: 3522 people in Hanoi, aged 12 and over, including those who have been vaccinated and have not been vaccinated against COVID-19. Venous blood collection, anticoagulation with heparin, quantification of antibody levels in the blood by electrochemiluminescence immunoassay method. Results: Among 3522 study participants, the number of people who had not been vaccinated, had received 1 shot and received 2 shots, respectively, were 633 (17.97%), 234 (6.64%) and 2656 (75.41%). The proportion of people who have been infected with the virus participating in the study is 1.45% and the number of people identified as F1 is 1.33%. The mean antibody concentrations in men and women were 1295.23 ± 2511.72 (U/mL) and 1536.61 ± 2678.59 (U/mL). The average antibody concentration generated after injection by each vaccine is 1199.3 ± 2209.92 respectively (AZD1222); 2461.73 ± 3283.13 (BNT162b2); 3793.67 ± 2685.12 (MRNA-1273); 153.36 ± 511.82 (BBIBP-CorV) (p < 0,001). The BNT162b2 and mRNA-1273 vaccines produced high antibody levels that gradually decreased after 4 months, while AZD1222 produced antibodies rapidly during the first month and then remained stable throughout the next 5 months. Conclusions: The concentration of SARS-CoV-2 antibodies in women is higher than in men. The group < 18 years old had the highest antibody levels while the group > 80 years old had the lowest antibody levels. The antibody levels produced by different vaccines are significantly different. Antibodies were highest after mRNA-1273  vaccination, lowest after BBIBP-CorV vaccination. There is a difference in the time to appear and maintain antibodies after vaccination with different vaccines, in which AZD1222 has an antibody retention time that lasts more than 5 months.