Adverse events and overall health and well-being after COVID-19 vaccination: interim results from the VAC4COVID cohort safety study
Amy Rogers, E. Douglas Rooke, S. V. Morant, Greg Guthrie, Alex S. F. Doney, Andrew Duncan, Isla S. Mackenzie, R.J. Barr, Filippo Pigazzani, Krists Zutis, Thomas M. MacDonald
Abstract
OBJECTIVES: To describe the incidence of adverse events (AEs), reactogenicity symptoms, menstrual changes and overall self-rated improvement in health and well-being after COVID-19 vaccination. DESIGN: VAC4COVID is an ongoing prospective, active observational, post-authorisation cohort safety study (PASS) of UK-approved vaccines for COVID-19 disease. SETTING: The study is conducted through a secure website (www.vac4covid.com) by MEMO Research, University of Dundee, UK. PARTICIPANTS: 16 265 adult (18 years or older) UK residents with a valid email address and internet access. INTERVENTIONS: Any UK-authorised COVID-19 vaccination. MAIN OUTCOME MEASURES: The outcomes reported in this interim analysis include AEs, reactogenicity-type AEs (headache, fatigue, muscle or joint pain, fever, nausea, dizziness or local vaccine reaction), menstrual changes and reported improvement in overall health and well-being. RESULTS: 11 475 consented participants (mean age 54.8 years) provided follow-up data between 2 February and 5 October 2021 (mean follow-up duration 184 days), by which date 89.2% of participants had received two vaccine doses. 89.8% of 5222 participants who completed a follow-up questionnaire in the 7 days after any COVID-19 vaccination reported no AEs. The risk of experiencing any event (not necessarily vaccine-related) requiring hospitalisation was less than 0.2%. 43.7% of post-vaccination follow-up records reported improvement in health and well-being. Reactogenicity-type reactions were more common in the week after the first dose of ChAdOx1 than BNT162b2 (7.8% vs 1.6%), but this relationship was reversed after the second dose (1.3% vs 3.1%). 0.3% of women reported menstrual symptoms after vaccination; no differences between vaccine type or dose order were detected. CONCLUSIONS: The study provides reassuring data on low rates of AEs after COVID-19 vaccination. Differences in reactogenicity-type AE profiles between ChAdOx1 and BNT162b2 and between first and second doses of these vaccines were observed. TRIAL REGISTRATION NUMBER: ISRCTN95881792; Pre-results.