Vaccinations were not associated with an increased risk of rheumatoid arthritis and may offer short-term protection when administered within one year, according to a recent review.
Researchers conducted an updated systematic review and meta-analysis to examine the association between vaccination and the risk of rheumatoid arthritis (RA). The study, published in BMC Public Health, included data from 16 observational studies—12 cohort and four case-control—comprising a more than 25 million participants.
Led by Hejing Pan of the School of Basic Medical Sciences of Zhejiang at the Chinese Medical University in Hangzhou, China, the researchers systematically searched PubMed, EMBASE, and the Cochrane Library through September 2024, and included studies that assessed the incidence or relapse of RA following vaccination with human papillomavirus (HPV), influenza, anthrax, herpes zoster, hepatitis B virus, tetanus, or coronavirus disease 2019 (COVID-19) vaccines. Risk of bias was evaluated using the Newcastle-Ottawa Scale, and the strength of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.
After using a random-effects model to account for high heterogeneity, the researchers found no significant association between vaccination and increased risk of RA, with an overall relative risk (RR) of 1.03. Subgroup analyses by vaccine type demonstrated no elevated risk of RA following HPV, influenza, anthrax, or COVID-19 vaccinations. The herpes zoster vaccine subgroup showed a higher RR, as reported in one included study.
Importantly, subgroup analysis by follow-up duration indicated a protective effect of vaccination on RA within the first year, with a RR of 0.92. This effect was not observed in studies with longer follow-up durations, which showed RR of 0.99. Sensitivity analyses supported the robustness of the overall findings. Meta-regression identified study design as a source of heterogeneity, but follow-up duration, vaccine type, and study quality were not significant contributors.
The level of evidence for all outcomes was rated as very low according to GRADE criteria. These results suggest no clear evidence that vaccination increases RA risk and point to a potential short-term protective effect following immunization. The researchers discussed the need for additional prospective studies to better evaluate vaccine safety in patients who are at risk for RA.
The researchers reported no competing interests.