COVID-19 is a coronavirus disease caused by the severe acute respiratory syndrome. According to the World Health Organization (WHO), coronavirus-2 (SARS-CoV-2) was responsible for 87,747,940 recorded infections and 1,891,352 confirmed deaths as of January 9, 2021. Antibodies that target the Sprotein are efficient in neutralizing the virus. Methodology: 180 samples were collected from clinical sources (Blood and Nasopharyngeal swabs) and from different ages and genders at diverse hospitals in Baghdad / IRAQ between November 5, 2021, to January 20, 2022. All samples were confirmed infected with COVID-19 disease by RT-PCR technique. Haematology analysis and blood group were done for all samples, and Enzyme-Linked Immunosorbent Assay used an IgG test. Results: Complete blood count showed white blood cells, haemoglobin and platelets were higher in group 1 (without vaccine) than in control. In contrast, lymphocytes showed a lower ratio, ABO group showed type A, and O has more susceptible than other types. IgG level showed a high ratio in group one. Conclusions: Vaccination plays an important role in COVID-19 patients and maintains normal levels of the parameters under study.
