Prevalence of adverse effects from COVID-19 vaccine among Iraqi adults: A retrospective cross-sectional study

Background: The production of a successful vaccine has become a global dream since the declaration of coronavirus disease 2019 (COVID-19) as a global pandemic by the World Health Organization. However, doubts abound about vaccine safety. In this study, we aimed to estimate and compare the prevalence of adverse effects in Iraqi adults from the COVID-19 vaccines used in Iraq. Methods: The study was a retrospective, cross-sectional study conducted in August 2021. An online-based questionnaire was applied randomly and distributed to individuals ( ≥ 18 years). Results: Among the 1000 vaccinated participants from different regions in Iraq, 66.0% were from middle Euphrates, 61.3% were women, and 62.2% were in their third to fifth decade of life. Approximately, 68.4% of the participants received Pfizer vaccine, and 42.5% had a previous history of COVID-19 infection Figure 1. Most of the participants (84.1%) suffered general adverse effects after vaccination, including (in sequence of appearance) fatigue, fever, headache, injection site signs, and axillary pain. Most studied factors have no significant correlation with post-vaccine adverse effects (P ≤ 0.05) such as age, sex, history of COVID-19 infection, and chronic disease. There was a significant correlation between adverse effects from the vaccine dose and age of recipients. Those with a history of comorbidities had a two-fold risk of developing adverse effects.Figure 1. Prevalence of general adverse effects in the participants after vaccination with three types of COVID-19 vaccines (N = 1000). Conclusion: Fatigue, fever, headache, injection site signs, and axillary pain were the most registered adverse effects, which were mostly mild to moderate. All the vaccines revealed an encouraging safety profile. Younger age, second vaccine dose, and presence of comorbidities were considered minor risk factors for more adverse effects.