Analysis of IgG Antibodies against SARS-CoV-2 and Seasonal Coronaviruses in Vaccinated Adults against COVID-19, 2021

Introduction: Variability in the immune response to vaccines can affect their efficacy; therefore, it is important to study the effectiveness of vaccination schedules against SARS-CoV-2 in different regions. Objective: To describe the IgG levels against SARS-CoV-2 and seasonal coronaviruses in individuals immunized against SARS-CoV-2 in Armenia, Colombia 2021. Methodology: This study was conducted on 100 immunized adults in Armenia, Colombia in 2021, immunized against SARS-CoV-2 vaccines. We used the Mikrogen (TM) recomLine SARS-CoV-2 IgG commercial kit to measure antibody levels against the nucleoprotein, spike protein, receptor-binding domain of SARS-CoV-2, and nucleoproteins of seasonal human coronaviruses (OC43, NL63, 229E, and HKU1). Results: The study revealed that 98% of individuals developed antibodies against SARS-CoV-2. We observed a higher level of IgG in individuals immunized with Pfizer. It was evident that antibody levels decreased with increasing age. On the other hand, 47% developed IgG antibodies against seasonal coronaviruses, with OC43 being the most common strain in men and NL63 in women. Conclusion: In the study population, we found the evaluated vaccines were effective to elicit specific humoral immune response. Those with a history of SARSCoV-2 infection displayed a more robust antibody response, further supporting the vaccines' efficacy in generating an immune response against the virus. Additionally, the analysis of seasonal coronaviruses indicates that this family of viruses is commonly circulating within our country.