Data reveal fewer real-world COVID vaccine side effects

A new real-world study finds fewer side effects after vaccination with the Pfizer/BioNTech and the AstraZeneca/Oxford COVID-19 vaccines than reported in phase 3 clinical trials, while another paper notes some instances of facial paralysis after receipt of the Pfizer or Moderna vaccine but no increased risk. In the first study, King's College London and other UK and US researchers mined data from the 627,383 users of the ZOE COVID Symptom Study app, who self-reported systemic and local side effects within 8 days of the receipt of one or two doses of the Pfizer vaccine or one dose of the AstraZeneca vaccine from Dec 8, 2020, to Mar 10, 2021. The study was published yesterday in The Lancet Infectious Diseases. After the first Pfizer dose, 13.5% of recipients reported side effects, compared with 22.0% after the second Pfizer dose and 33.7% after the first AstraZeneca dose.