Factors Associated With Self‐Medication to Mitigate Vaccine Reactions After <scp>COVID</scp> ‐19 Vaccination: A Prospective Cohort Study

OBJECTIVE: Management of vaccine reactions with analgesics/antipyretics can enhance acceptance and adherence to future vaccinations. However, inappropriate self-medication may pose health risks, particularly for individuals with chronic conditions. The aim of this study was to identify demographic, clinical, and psychosocial factors associated with self-medication behavior after COVID-19 vaccinations. METHODS: Monocentric prospective cohort study at a vaccination center in Germany between August 16 and 28, 2021 with adults receiving a second dose of mRNA-based COVID-19 vaccines. We used linear regression analyses to examine the association of self-reported factors with the amount of self-medication after vaccination. RESULTS: A total of 1616 participants (median age 34 years, 52% females) were included, with 536 (33.2%) reporting the use of self-medication. Used substances were nonsteroidal anti-inflammatory drugs n = 345 (21.3%), paracetamol n = 186 (11.5%), acetylsalicylic acid n = 48 (3.0%), and metamizole n = 18 (1.1%). The highest intake of any analgesic/antipyretic was observed on the first day after vaccination n = 393 (24.3%). Factors associated with increased self-medication included premedication with analgesics/antipyretics (B: 0.545; 95% CI: 0.442; 0.651), administration of the mRNA-1273-vaccine compared to the BNT162b2-vaccine (B: 0.293; 95% CI: 0.188; 0.397), female gender (B: 0.159; 95% CI: 0.07; 0.249), prior experiences of vaccine reactions (B:0.117; 95% CI: 0.054; 0.18), expectations of vaccine reactions (B: 0.063; 95% CI: 0.003; 0.123), and the presence of common chronic conditions. A higher satisfaction with the vaccination process (B: -0.129; 95% CI: -0.222; -0.039) was associated with lower rates of self-medication. CONCLUSIONS: Factors influencing self-medication behavior after vaccination exist and could be assessed prior to vaccine administration. The observed association of previous experiences as well as expectations of vaccine reactions suggests that nocebo effects contribute to self-medication practices.