Abstract
Introduction: At the end of 2019, a novel coronavirus was identified as the cause of a cluster of pneumonia cases in Wuhan, China [1, 2]. It is generally accepted that the world will not return to the pre-pandemic normally situation until safe and effective vaccines become available. However, the rare and unknown adverse events following immunization (AEFIs) are not usually detected in the clinical trials. Thus, monitoring the safety of COVID-19 vaccines in real-world population is essential. Objective: To perform a post-marketing safety surveillance of AEFIs of COVID-19 vaccines. Methods: A prospective cohort study conducted and followed subjects who received COVID-19 vaccines from the first day of vaccination for seven days after the first and second doses, then biweekly for three months. All vaccinee demographic information, vaccine type, co-morbidities, concomitant medications and AEFIs were collected by phone through a standardized online questionnaire. Baseline characteristics and AEFIs were analyzed descriptively by SPSS software. AEFIs were classified according to medical Dictionary for Regulatory Activities (MedDRA). Results: 544 subjects of 8867 agreed to be part of the study. Among them 218 subjects completed the study, of them 110 individual were male (50.5%) and 108 (49.5%) were female; the median age was 33 year. Out of 218, 87 (39.91%) individual received Pfizer-BioNTech vaccine, 45(20.64%) individual received Oxford/AstraZeneca vaccine, 5(2.3%) individual received Moderna vaccine, and 81 (37.2%) received two different COVID-19 vaccines. The reported events were categorized to system organ class (SOC) according to MedDRA. The most reported SOCs were respiratory, thoracic and mediastinal disorders (n = 8 with Pfizer-BioNTech vaccine, n = 4 with Oxford/ AstraZeneca vaccine, n = 1 with Moderna vaccine), Injection site reactions (n = 66 with Pfizer-BioNTech vaccine, n = 34 with Oxford/ AstraZeneca vaccine, n = 5 with Moderna vaccine), nervous system disorder (n = 20 with Pfizer-BioNTech vaccine, n = 18 with Oxford/ AstraZeneca vaccine, n = 3 with Moderna vaccine),infections and infestations (n = 23 with Pfizer-BioNTech vaccine, n = 33 with Oxford/AstraZeneca vaccine, n = 4 with Moderna vaccine), musculoskeletal disorders (n = 53 with Pfizer-BioNTech vaccine, n = 46 with Oxford/AstraZeneca vaccine, n = 7 with Moderna vaccine). Only 10 (4.6%) cases were serious and required medical intervention to overcome the harm. Conclusion: The preliminary results of the study shows the shortterm safety profiles of included COVID-19 vaccines are acceptable in Saudi Arabia.