Introduction: COVID-19 vaccination was introduced in March 2021 to curb the pandemic. We studied the adverse reactions (AR) after Pfizer-BioNTech vaccination among healthcare workers (HCW) in Sibu and determined the association of allergy history and post-vaccination AR. Methods: This is a cross-sectional observational study involving HCW given the vaccine in February and March 2021. Post-vaccination AR records were retrieved for all HCW who completed the vaccination. Results: There were 2,131 dose 1 and 1,620 dose 2 reports available. Eighteen types of AR were reported, namely pain on injection site, body ache, headache, joint pain, tiredness, sleepiness, chills, dizziness, itchiness, numbness, cough, lymph node swelling, diarrhoea, shortness of breath, palpitation, chest pain, nausea and fever. The common AR(>20%) were pain at the injection site, tiredness, headache, body ache, sleepiness and chills. The AR were all significantly higher for dose 2 (p<0.05). HCW with allergy history were more likely to have mild AR in dose 1 (OR=1.77; 95%CI: 1.30, 2.40, p<0.001) and dose 2 (OR=1.98; 95%CI: 1.35, 2.91, p<0.001); and severe AR in dose 1 (OR=8.02; 95%CI: 2.06, 31.20, p<0.003) and dose 2 (OR=21.35; 95%CI: 2.56, 177.80, p=0.005). Three HCW were admitted due to severe body rashes and shortness of breath. No death was reported. Conclusion: Although Pfizer-BioNTech vaccination causes local and systemic AR, they were generally well tolerated. Some more-prevalent AR such as headache, sleepiness and tiredness and more severe AR such as dizziness, shortness of breath and chest pain warrant careful monitoring among elderly and more vulnerable groups. Disclaimer: Abstract text might vary slightly from what is displayed in the e-poster.

This poster was submitted to the 14th National Conference for Clinical Research (NCCR) in August 18-20, 2021. https://nccrconference.com.my/