No disproportionate reporting of inflammatory arthritis following COVID-19 vaccination: a pharmacovigilance study...

To assess whether inflammatory arthritis was disproportionately reported as an adverse event following COVID-19 vaccination compared to other vaccines, using data from the Vaccine Adverse Event Reporting System (VAERS).

We performed a retrospective analysis of VAERS data from December 2020 to December 2024, focusing on inflammatory arthritis as adverse event following administration of the BNT162b2, mRNA-1273, and Ad26.COV2.S vaccines. Data on vaccine dose, demographic characteristics, and symptom onset were collected. A structured query based on MedDRA terms was used to identify the reports of inflammatory arthritis. Crude reporting rate of arthritis was calculated. Disproportionality analysis was conducted using the proportional reporting ratio (PRR), reporting odds ratio (ROR), and Bayesian information component (IC), initially comparing COVID-19 vaccines to all other vaccines in VAERS, and then with stratification by age, sex, and comparator vaccine (influenza and herpes zoster).

Among 651,850 valid reports, 5580 events of inflammatory arthritis were identified, yielding a CRR of 13.8 cases per million doses administered. Most reports involved females (72 %) and occurred within a median of 2 days post-vaccination. In the overall population, inflammatory arthritis was not disproportionately reported after COVID-19 vaccination (PRR: 0.999, 95 % CI: 0.883 to 1.130; ROR: 0.878, 95 % CI: 0.777 to 0.994; IC: -0.008, 95 % CrI: -0.046 to 0.030). Disproportionality analysis in subgroups confirmed the absence of signal across age and sex strata.

Our findings demonstrate that there is no disproportionate reporting of inflammatory arthritis following COVID-19 vaccination compared to other vaccines, supporting the overall safety of COVID-19 vaccines.