Assessment of Longevity of COVID-19 Vaccination Among Hematology Healthcare Workers

Abstract

Background The SARS-CoV-2 outbreak caused pneumonia and respiratory distress worldwide in December 2019. It was later recognized as the COVID-19 pandemic, so COVID-19 specific vaccines were soon developed and used for immunization of global communities. The primary objective of this study is to measure the concentration and persistence of IgG antibodies against SARS-CoV-2in healthcare employees of Hiwa Hospital for Cancer in Sulaimani City, Iraq. Patients and Methods : Blood samples were collected from 49 healthcare employees in Hiwa Hospital who received the Pfizer-BioNTech COVID-19 vaccine. The participants were recruited through a questionnaire containing information about age, gender, number of vaccination doses, and frequency of previous COVID-19 infections. The anti- COVID-19 antibodies in the blood samples were analyzed using the ELISA technique. Results The age of the participants ranged from 30 to 39 years old (mean 38.9 ± 10.29), with 31 (63.5%) being males and 18 (36.7%) being females. The anti COVID-19 specific IgG titers were 12.5, 13.45, and 13.8 mg/dL after 6, 12 and 18 months of vaccination, respectively. Besides, 10.2% of the participants have received three doses of the vaccines, 85.7% have received two doses, and only (4.1%) received a single dose. Moreover, a faction (22.4%) of the participants had a very low positive titer of anti COVID-19 specific IgM without obvious signs and symptoms of the disease. Conclusion The Immunoglobulin G antibody titer against COVID-19 remains at a protective level for at least eighteen months.