Prevalence of Covishield COVID-19 Vaccine (ChAdOx1 nCoV-19) Adverse Effects among Health Care Workers in Sri Lanka

Abstract

Purpose: A Community vaccination programme is the best approach to combat COVID-19 pandemic. The first priority was given to the health care workers (HCWs) with the introduction of Indian Covishield (ChAdOx1 nCoV-19) vaccine to Sri Lanka since February 2021. An independent post-vaccine surveillance is important to identify the occurrence of adverse effects(A/E) in the population. Methods & Materials: A multicentered cross-sectional survey was conducted in four provinces of Sri Lanka to estimate the prevalence of A/E after covishield vaccination A/E among HCWs after the first dose. A self-administered questionnaire was used to gather demographic data and A/E. Data was analysed using descriptive statistics. Results: Of 4834 participants, 3500(72.4%) were females. The median age was 42.23(SD±9.64) years. Only 0.8%(n=31) persons has had Covid infection in the past. 2.2% were breastfeeding mothers and 0.2% were pregnant ladies.87.4% of persons had at least one A/E and 53.1% had local A/E. Body aches(68.2%), headaches(63.8%), fever(58%), chills 51.4%), fatigue(41.2%), arthralgia(38.1%) and rigors (32%) were the most commonly reported systemic A/E.Most of the systemic A/E were more prevalent among the ≤42-year-old group, and females. Their duration was mainly 24 hours. Mean duration of onset of fever is 9.76 hours.Pain and redness at the site were the most commonly reported local A/E.All of the local A/E were more prevalent among the ≤42-year-old group and females. Mean duration of pain at the site is 4.47 hours.1.7%(n=61) had reactions within first 20 minutes. 0.08%(n=4) developed anaphylaxis, 0.8%(n=31) had urticaria.15.4% had at least one comorbidities but there were no significant association between having a comorbidity and developing systemic or local.1.3% had history of drug or food allergies, they did not show significant relation to current vaccine induced allergies or anaphylaxis.69.2% attended the routine work despite having minor A/E. 0.13%(n=7) were hospitalised and treated. 22.4% were stayed at home and rested for 24-48 hours due to A/E. Conclusion: Eventhough more than 60% reported minor A/E, there were only a few serious A/E. A/E were more prevalent in younger age and females. Overall, the first dose of the Covishield vaccine was well-tolerated by HCWs.