Antibody Response to Sars-CoV-2 in Adults After 18 Months of Second Dose Vaccination of Astra Zeneca

Abstract

Vaccination is one of the methods of preventing SARS-Cov-2 infection. Although the efficacy of several vaccines has been observed, it is unknown how long the antibodies remain in the body. The purpose of this study was to examine the antibody titers in adults, 18 months after receiving two doses of the Astra Zeneca vaccine. This is a cross-sectional study with adult subjects who received two doses of the Astra Zeneca vaccine in the Bogor area, conducted in 2023. To evaluate antibody titers (IgG) in serum specimens, the Chemiluminescent Microparticle Immunoassay (CMIA) method was utilized. The antibody titer ≥ 50.0 AU/mL was considered positive. The characteristics 122 subjects were mostly: female (63,1%), 36-45 years old, senior high school graduate (45.9%), unemployed (62,3%), had hypertension history (44.7%), and had no COVID-19 infection during the last six months. The results demonstrate that all the subjects had a positive SARS Cov-2 antibody titer, with a range titer of 87 - 80260 AU/mL and a geometric mean titer of 3246.4 AU/mL. In conclusion, this study found that the two doses of the Astra Zeneca vaccine made a significant contribution to the acquisition of anti-SARS-CoV-2S antibodies in adults.