Abstract
Comprehensive safety and efficacy studies of COVID-19 vaccines might reduce the apprehension of the general population about the adverse reactions and duration of protection offered by them. The study aimed to conduct a systemic review on the four COVID-19 vaccines (AstraZeneca, Pfizer, Moderna, and Janssen) approved in Saudi Arabia. The study was conducted by reviewing the published articles from electronic databases such as PubMed, Embase, Cochrane Library and Web of Science using the search terms "COVID-19", "Vaccine", "Safety", "Efficacy" and "Human trials" and as per the standard guidelines for systemic review. The review analyzed eighteen articles and the data from them were evaluated to analyze the safety and efficacy of the vaccines in different groups of population such as males, females, those above 18 years and people with co-morbidities. The common local reactions observed after vaccination were pain at the site of injection (40-70%), redness (16-30%), swelling (18-39%) and tenderness (20-40%). The systemic reactions reported were fever (40-60%), chills (12-23%), fatigue (44-65%), headache (30-42%) and muscle pain (15-40%). The efficacy was observed to be above the threshold value (60%) stipulated by the WHO. However, precautions need to be followed while vaccinating special groups of population such as those that are pregnant, lactating or experiencing severe illness. Additionally, the rare and serious adverse events reported remotely after vaccination need more studies.