Common Adverse Events from Mixing COVID-19 Vaccine Booster in Hanoi, Vietnam

Abstract

Background: Mixing vaccines was proposed as a solution to tackle supply chain interruptions during the crisis of the COVID-19 pandemic. This study aimed to investigate the safety of mixing COVID-19 vaccines for a booster dose in Hanoi, Vietnam. Method: A cross-sectional study was conducted via a telephone-based interview to identify the adverse events following COVID-19 vaccination among 719 participants in Hanoi, Vietnam. Results: In total, 45.76% of participants experienced at least one adverse event following two doses of the COVID-19 vaccine. Most of the adverse events were local effects with mild symptoms such as fever, headache, muscle pain, and/or pain at the site. In general, matching two doses in the same vaccines was not associated with the adverse events as compared to mixing vaccines (OR = 1.43, 96%CI: 0.93–2.2), except matching two doses of Pfizer (OR = 2.25, 95%CI: 1.33–3.82). Conclusion: The findings of this study suggest the overall safety of mixed vaccination. In light of the vaccine shortage, mixing vaccinations for COVID-19 prevention is a good solution. Further studies with larger cohorts and investigating immunity following mixing vaccines are needed to elucidate the mechanism.

Adverse Events Following Immunization with Novel Oral Polio Vaccine Type 2, and the Experience and Challenges of Reporting in Sierra Leone

“…These serious events included vomiting (42), anaphylactic reactions (two), paralysis (11), seizure and myalgia (12), loss of consciousness and respiratory distress (four), pneumonia and pain (two), anemia (three), facial edema (three), and jaundice (one).…”