Background: The coronavirus 2 that causes severe acute respiratory syndrome is the source of the contagious sickness known as coronavirus disease 2019, The first case was detected in Wuhan, China, in December of this year. Since then, a pandemic has occurred due to the disease's global spread. The IgG antibody is a large, Y-shaped protein that aids in the immune system's ability to identify and eliminate foreign substances like bacteria and viruses. The antibody detects the antigen, a distinct molecular molecule of the virus.Objective: This research aimed to know which were more infected males or females? and the levels of antibodies produced when infected with the emerging virus as well as to compare the antibodies formed after taking two doses of its vaccines, which include Pfizer, AstraZeneca, and Sinopharm vaccines that used in Iraq by measuring the level of Serum IgG using enzyme-linked immune-sorbent assay technology. Materials and Methods: In the current study, 100 Iraqi patients with covid-19 disease and 30 Iraqi healthy control were included, and 20 previously uninfected individuals who received the vaccine, and 20 previously infected individuals who took the vaccine (for each type of the three vaccines). Samples were collected 21 days after the second dose and also from 3 to 6 months after the second dose by measuring the level of serum IgG using enzyme-linked immune-sorbent assay technology. The study was conducted from September 2021 to February 2022. Blood samples were collected in Baghdad Teaching Hospital (Corona patients' isolation center) in Baghdad, Iraq. Results:The study showed that infection with COVID-19 increases the proportion of antibodies IgG, and it was also found that the best type of vaccine is the AstraZeneca vaccine for raising IgG, and males are more susceptible for infection than females. Conclusion: Elevation of immunoglobulin G in blood depends on the severity of the infection and the Effect of vaccine.