Chadox1

A longitudinal study through the panel design was conducted to study the COVID-19 vaccines' stimulation to the immunity status as well as adverse side effects among staff in health-care facilities in Duhok province in Kurdistan region, Iraq. Participants of this study received 1 of the 3 available vaccines (Pfizer BioNTech [BNT162b2], Oxford/AstraZeneca [ChAdOx1], and Sinopharm [BBIBP-CorV]), and the time period for this study was between June 2021 and June 2022 for those who were working in public health-care facilities in Duhok Province, Iraq.

The study recruited 300 health staff from public health-care facilities in Duhok province, of which 300 participants were included in the first phase 1 mo after the second dose; 279 participants in the second phase 5 mo after the second dose; and 256 participants in the third phase of 9 mo after the second dose. Following inclusion criteria, the present study recruited health staff who received 2 doses of the COVID-19 vaccine. Vaccine types varied and included Pfizer BioNTech (BNT162b2), Oxford/AstraZeneca (ChAdOx1), and Sinopharm (BBIBP-CorV). Participants were included in this study if they gave consent and were willing to participate and commit to studying requirements. Contrary, people with cancer or human immunodeficiency virus (HIV) disease were excluded. The study sample was recruited using a vaccine database from the Duhok health governorate through a random sampling method. Initially, 904 healthcare workers who completed their vaccination by receiving 2 doses were recorded in the vaccination department and included in the original database for each vaccine. Then simple random sampling was performed using the Excel random formula to select 100 individuals for each vaccine to be included in the study.