Background : Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. Most people who fall sick with COVID-19 will experience mild to moderate symptoms and recover without special treatment. However, some will become seriously ill and require medical attention. Objective : The aims of this study is to explore the different side effects associated with the three most common vaccines against Covid-19 in Nineveh, Iraq. Such study will aid healthcare workers and policy makers in the betterment of medical care for concerned patients, therefore, improving their quality of life. Patients and methods:The study is a prospective case series study, included 498 participants, 48.1% of them were between the ages 18 to 30 years, 54.0% are married, Only these two characteristics were significantly different among vaccine users (p-value = .041 and .001, respectively). Results: Frequency of Adverse Reactions Based on the Vaccine For the first dose, the most common symptoms were body/joint pain, headache, fatigue and fever. The frequency of these symptoms in addition to respiratory symptoms were significantly more frequent within the AstraZeneca vaccine (all p <.001). While the Pfizer-BioNTech vaccine had significantly higher frequency of no experienced symptoms (p <.001). For the second dose, the trends of the adverse effects did not change. However, the symptoms of joint/body pains, headache, fatigue, and fever were significantly more pronounced in the Pfizer-BioNTech vaccine (all p <.001). Conclusions and recommendations:In conclusion, we noticed that post vaccine side effects are common with all vaccines but are more pronounced in new technology vaccines. The application of a governmental surveillance system adverse effect severity is highly recommended.