Comparison of IgG -Predominant Antibody Responses between Conventional Inactivated and mRNA SARS CoV-2 Vaccines Administrated in Jordan

Introduction: Different COVID-19 vaccines can affect various body systems, including the immune system, leading to distinctions in immune responses like natural killer cell cytotoxic activity, complement system function, and B-cell antibody production among vaccinated and non-vaccinated individuals. In Jordan, so far, there is no study exploring these immune response variations for four COVID-19 vaccines, along with the factors influencing the response and post-vaccination clinical outcomes. Methods: This study focuses on the humoral responses of 350 adult participants. Through participant interviews, one blood sample was collected for subsequent laboratory testing, utilizing the Enzyme-Linked Immunosorbent Assay (ELISA) method to examine the presence of COVID-19 antibodies in participants plasma. A Chi-square test was performed to test for the statistical significance. Results: Our results indicate significant differences in positive antibody response efficiency (p value 0.001) among participants who received two or three doses of COVID-19 inactivated and mRNA vaccines. The order of higher positive antibody frequency is as follows: Pfizer (90.5%), Sputnik V (88.1%), Sinopharm (78.8%), and AstraZeneca (65.8%). There is a noticeable inclination towards the efficacy of the Pfizer-BioNTech vaccine, evidenced by the highest levels of antibodies in recipients of this vaccine. Our study revealed that various factors, including gender, age, and smoking status prior to infection, play a role in significant contributors affecting immune response and influencing the effectiveness of these vaccines. Conclusion: All the four types of COVID-19 vaccines administered in Jordan demonstrated effectiveness. We recommend studying the ability of B lymphocytes present in the peripheral blood and the effect of T-regulatory cells by flow cytometry in recipients who have high positive titers.