Next, we lack information about co-morbidities and chronic therapies of the participants that may possess affected their immune response to vaccines or SARS-CoV-2 infection. within SP1 the 28th day time from your administration of the second dose of the BBIBP-CorV and Gam-COVID-Vac vaccine, stratified by sex and age. (DOCX) pone.0263468.s005.docx (25K) GUID:?15D8CE24-D7B0-4F5C-B1C0-17C768996128 S4 Table: Antibody levels within the 28th day time from your administration of the second dose of the BNT162b2 vaccine or after COVID-19 recovery, stratified by sex and age. (DOCX) pone.0263468.s006.docx (25K) GUID:?C54449EA-DFE0-49E2-B2E5-A9340D5FA3EC S5 Table: Antibody levels within the 28th day from your administration of the second dose of the BBIBP-CorV vaccine or after COVID-19 recovery, stratified by sex and age. (DOCX) pone.0263468.s007.docx (25K) GUID:?C124388A-999D-4FD6-B9F1-5C9B940B3D12 S6 Table: Antibody levels within the 28th day time from your administration of the second dose of the Gam-COVID-Vac vaccine or after COVID-19 recovery, stratified by sex and age. (DOCX) pone.0263468.s008.docx (25K) GUID:?A4FA976E-661A-414B-8929-78D48186133A Data Availability StatementAll relevant data are within the manuscript and its Supporting information documents. Abstract Background Mass vaccination is the key element in controlling current COVID-19 pandemic. Studies comparing immunogenicity of different COVID-19 vaccines are mainly lacking. We aimed at measuring anti-S antibody (Ab) levels in individuals fully vaccinated with BNT162b2, BBIBP-CorV and Gam-COVID-Vac, as well as with COVID-19 convalescents. Methods With this cross-sectional study, serum was collected from 400 age- and sex-matched participants, 100 fully vaccinated with BNT162b2, 100 with BBIBP-CorV and 100 with Gam-COVID-Vac within the 28th day time after the second vaccine dose, and 100 recovered from COVID-19 at least 28 days after sign(s) resolution. Sera were analyzed using the LIAISON SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Saluggia, Italy). Wilcoxon rank-sum or KruskalCWallis checks was utilized for assessment of Ab levels. Results Highest imply value (210.11, SD = 100.42) was measured in the BNT162b2 group, followed by Gam-COVID-Vac (171.11, SD = 120.69) and BBIBP-CorV (68.50, SD = 72.78) AU/mL (p 0.001). Significant variations in antibody levels were found between BNT162b2 and BBIBP-CorV (p 0.001), BNT162b2 and Gam-COVID-Vac (p = 0.001), as well while BBIBP-CorV and Gam-COVID-Vac organizations (p 0.001). Percentage of seropositive was 81% in the convalescent group, 83% in BBIBP-CorV vaccinated and 100% in BNT162b2 and Gam-COVID-Vac. When comparing measured antibody levels in vaccinated to the people in COVID-19 recovered, significantly higher antibody levels were found for vaccinated with BNT162b2 (p 0.001), and with Gam-COVID-Vac (p 0.001), while for BBIBP-CorV there was no statistically significant difference (p = 0.641). Conclusions All three investigated vaccines, BNT162b2, BBIBP-CorV and Gam-COVID-Vac, provide robust immune response 28 days after the second dose of vaccine, in the majority of participants. All individuals vaccinated with BNT162b2 and Gam-COVID-Vac seroconverted, while in vaccinated with BBIBP-CorV and COVID-19 recovered seroconversion rates were lower. Although less potent compared to additional two vaccines, immune response after BBIBP-CorV was much like response measured in convalescents. Challenge still remains to examine dynamics and toughness of immunoprotection. Intro Mass vaccination is the key element in controlling the coronavirus disease 2019 (COVID-19) pandemic and it is widely acknowledged Capromorelin that implementation of global vaccination programme is definitely pre-requisite for world to return to normality [1, 2]. Joint attempts to put the SARS-CoV-2 epidemic under control became a global priority and offers resulted in quick action in development of the vaccines [3]. Numerous vaccine platforms, including mRNA, adenovirus vectors, and inactivated disease, have been utilized for the SARS-CoV-2 vaccine development [4]. Data from phase 3 clinical tests of different vaccines showed motivating efficacies against symptomatic COVID-19 ranging from 67% to as much as 95% [5]. In Serbia, the COVID-19 vaccination marketing campaign started on December 24, 2020. Recommended immunization programme was implemented and vaccines were offered free of charge. Serbian Medicines Agency authorized four vaccines for use in population, namely Pfizer-BioNTech BNT162b2 (Comirnaty?) was authorized on December 23rd, 2020, Sinopharm BBIBP-CorV (Vero Cell?) on January 3rd, 2021, Gam-COVID-Vac (Sputnik V?) on January 18th, 2021, and Oxford/AstraZeneca ChAdOx1-S/nCoV-19 AZD1222 (Vaxzevria?) on February 20th, 2021 [6]. These vaccines are based on different platforms and have varied mechanisms of action, which were explained elsewhere [7C9]. It Capromorelin is generally approved that higher antibody (Ab) levels and neutralizing antibodies specific for spike (S) protein of SARS-CoV-2 levels in particular, are likely to control the disease [10]. Though all vaccines against SARS-CoV-2 have been shown to induce good humoral immune response, including neutralizing antibodies against the S protein [4], studies comparing immunogenicity of varied COVID-19 vaccines are mainly lacking. Thus, measuring anti-S Ab levels in blood circulation of similar individuals vaccinated with different vaccines, at the same time points following vaccination and using the same immunological assay that quantifies antibodies binding to S protein, could enable a comparison of the immunogenicity between different vaccines. On the other hand, natural immunity after illness may differ from post-vaccination immunity. Anti-S antibodies are recognized in many but not all convalescent individuals, with levels Capromorelin varying much between individuals. Moreover, both neutralizing antibody titers and total anti-S antibody titers have positively correlated with COVID-19 disease.