COVID-19 anti immunoglobulin G antibodies serum levels among health care workers post COVID -19 vaccination: A single center study

Coronavirus disease 2019 (COVID-19) pandemic has urged the scientific community internationally to find answers in terms of therapeutics and vaccines to control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The post vaccination immune response differs between individuals especially health care workers who are the first line of defense to combat this disease. Our aim was to measure levels of anti-IgG antibodies titer post COVID-19 vaccination among health care workers in Suez Canal University Hospital. The study included 141 healthcare workers. Of these, 54 were physicians, 80 nurses, 6 health service workers, and one security guard. We used the Roche Elecsys Anti-SARS-CoV-2 assay for serological detection of IgG. Seropositive was found in 96.5% of the participants, and 43.3% of them had evidence of the prior history of COVID-19 infection. The highest titers of IgG in sera were found in the youngest age groups (20 - <35) years with a mean of 335.1 U/ ml. Participants who received the Sinovac vaccine had the highest mean IgG titer, 354.6U/ml; followed by Sinopharm (mean 352.15 U/ml) then Pfizer and Moderna (311.7U/ml) and AstraZeneca vaccine had the least mean level (267.31U/ml). Fatigue was the most significant short side effect occurring with 34% of the participants. In conclusion, there was a significant rising in serum IgG titer post-vaccine, and better antibody response in those previously infected with COVID-19. The post-COVID-19 vaccine serum IgG titers were affected by age, prior history of COVID-19 infection, and type of vaccine while short side effects post-vaccination may be affected by age and type of the vaccine.