Analysis Study of Vaccinated Peoples with Coronavirus patients and measurement Immunoglobulin G levels

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), spread rapidly worldwide and became a major global health concern. According to the World Health Organization (WHO), millions of infections and deaths were reported during the pandemic. Antibodies directed against the viral spike protein play an essential role in viral neutralisation and immune protection. This study included 186 blood and nasopharyngeal swab samples collected from individuals of different ages and both sexes at several hospitals in Baghdad, Iraq, between 7 September 2022 and 16 April 2023. SARS-CoV-2 infection was confirmed in all participants using reverse transcription–polymerase chain reaction (RT-PCR). Haematological parameters and ABO blood groups were determined, while anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Complete blood count analysis showed that white blood cell counts, haemoglobin concentrations, and platelet counts were higher in Group 1, comprising unvaccinated patients, than in the control group, whereas lymphocyte counts were lower. Analysis of ABO blood groups showed that blood groups A and O were more frequently represented among infected participants than the other blood groups. Moreover, anti-SARS-CoV-2 IgG concentrations were elevated in Group 1. These findings indicate that vaccination status may be associated with differences in haematological and immunological parameters among individuals infected with SARS-CoV-2. Further controlled studies are required to confirm these associations and determine their clinical significance.