Abstract
BackgroundA nationwide vaccination program against coronavirus disease 2019 (COVID-19) was started in Mongolia 4 months after the first local transmission, which occurred in November 2020. Previous studies have reported that two doses of COVID-19 vaccine result in increased antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A study was conducted in Mongolia 2 weeks after the second vaccine dose. In the present study, the serum levels of antibodies of individuals 6 months after natural SARS-CoV-2 infection were compared with those of individuals who had not been infected or had been infected but had received two doses of vaccine, including BNT162b2, ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BBIBP-CorV, which were used for COVID-19 in Mongolia. MethodsOf the 450 participants in this study, 237 (52.66%) were female and 213 (47.33%) were male. Four hundred people with or without SARS-CoV-2 infection who received two doses of 4 different COVID-19 vaccine participated in the vaccine groups and vaccine plus SARS-CoV-2 infection groups (50 in each group) and 50 individuals previously infected with SARS-CoV-2 participated in the unvaccinated group. Total antibody against SARS-CoV-2 infection, anti-SARS-CoV-2 N and S protein human IgG, and antibody inhibiting RBD–ACE2 binding were tested. ResultsIn the BNT162b2 vaccine group, total antibody against SARS-CoV-2 remained constant until 6 months, while the other vaccine groups showed a significant decrease, as compared to the unvaccinated group. The level of anti-SARS-CoV-2 S-RBD protein IgG was significantly increased in the ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BNT162b2 vaccines groups as compared to the unvaccinated group. Participants in the BNT162b2 vaccine group had higher ACE2 inhibition efficiency compared to the other vaccine groups as well as the unvaccinated group. ConclusionsThe BNT162b2 vaccine showed the highest level of antibody against SARS-CoV-2, followed by the BBIBP-CorV, Gam-COVID-Vac, and ChAdOx1 n-CoV-19 vaccines. The level of antibodies was increased in people infected with SARS-CoV-2 after vaccination, as compared to uninfected but vaccinated individuals.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
