Immunogenicity of Oxford-AstraZeneca COVID-19 Vaccine in Vietnamese Health-Care Workers

• DOI: 10.4269/ajtmh.21-0849
• Publication Date: 2022-01-07T13:01:50Z
• Authors: Nguyen Van Vinh Chau; Lam Anh Nguyet; Nguyen Thanh Truong; Le Mau Toan; Nguyen Thanh Dung; Le Manh Hung; Mai Thanh Nhan; Dinh Nguyen Huy Man; Nghiem My Ngoc; Huynh Phuong Thao; Tran Nguyen Hoang Tu; Huynh Kim Mai; Do Thai Hung; Nguyen Thi Han Ny; Le Kim Thanh; Nguyen To Anh; Nguyen Thi Thu Hong; Le Nguyen Truc Nhu; Lam Minh Yen; Marc Choisy; Tran Tan Thanh; Guy Thwaites; Le Van Tan; _ _
• Keywords: Male; Economics; Social Sciences; Infectious disease (medical specialty); FOS: Health sciences; Coronavirus Disease 2019; Tertiary Care Centers; Immunogenicity, Vaccine; 0302 clinical medicine; Sociology; Disease; Internal medicine; Vaccines; Middle Aged; 16. Peace & justice; Immunogenicity; FOS: Sociology; FOS: Philosophy, ethics and religion; 3. Good health; Infectious Diseases; Vietnam; Seroconversion; Health; Antibody response; Medicine; Female; Vaccination Intention; Demographics; Research Article; Adult; COVID-19 Vaccines; Health Personnel; Immunology; Vietnamese; Coronavirus Disease 2019 Research; Vaccine Hesitancy; 03 medical and health sciences; Asian People; ChAdOx1 nCoV-19; Virology; Health Sciences; Humans; Antibody; Economic growth; Aged; Demography; SARS-CoV-2; FOS: Clinical medicine; Immunity; Health care; COVID-19; Linguistics; Neutralizing antibody; Antibodies, Neutralizing; Coronavirus disease 2019 (COVID-19); Philosophy; FOS: Languages and literature; Factors Affecting Vaccine Hesitancy and Acceptance

ABSTRACT. We studied the immunogenicity of the Oxford-AstraZeneca vaccine in health-care workers of a major infectious diseases hospital in Vietnam. We measured neutralizing antibodies before and 14 days after each dose, and at day 28 and month 3 after dose 1. A total of 554 workers (136 men and 418 women; age range, 22–71 years; median age, 36 years) participated with the study. Of the 144 participants selected for follow-up after dose 1, 104 and 94 gave blood for antibody measurement at weeks 6 and 8, and at month 3 after dose 1, respectively. The window time between the two doses was 6 weeks. At baseline, none had detectable neutralizing antibodies. After dose 1, the proportion of participants with detectable neutralizing antibodies increased from 27.3% (151 of 554) at day 14 to 78.0% (432 of 554) at day 28. Age correlated negatively with the development and the levels of neutralizing antibodies. However, at day 28, these differences were less profound, and women had a greater seroconversion rate and greater levels of neutralizing antibodies than men. After dose 2, these age and gender associations were not observable. In addition, the proportion of study participants with detectable neutralizing antibodies increased from 70.2% (73 of 104) before dose 2 (week 6, after dose 1) to 98.1% (102 of 104) 14 days later. At month 3, neutralizing antibodies decreased and 94.7% (89 of 94) of the study participants remained seropositive. The Oxford-AstraZeneca COVID-19 vaccine is immunogenic in Vietnamese health-care workers. These data are critical to informing the deployment of the COVID-19 vaccine in Vietnam and in Southeast Asia, where vaccination coverage remains inadequate.