Epidemiological study of influenza vaccination and rheumatoid arthritis

Background/Aims Rheumatoid arthritis (RA) has been known as an autoimmune and inflammatory disease. Previous studies found individuals with RA had a two-fold increased risk of infections compared to general population. For infectious disease as influenza, vaccination may confer protection. However, whether or not influenza vaccination is safe to be given to genetically predisposed individuals with RA still on debate since there is an evidence that influenza vaccine as inflammatory stimulus could induce RA. Methods This study aims to provide an up-to-date epidemiological evidence between influenza vaccination and RA among American adults from 18 years old. Methods With case-control study design using 2014 Full year consolidated data in Medical Expenditure Panel Survey (MEPS), the association between influenza vaccination and RA among adult 18 years old and above were assessed using logistic regression analysis adjusted for potential covariates (age, sex, comorbidity, body mass index (BMI), education, smoking status, and insurance status) to estimate odds ratio (OR). Results In the crude model, individuals who reported receiving influenza vaccine were 2.02 (95% CI: 0.97-4.22) times more likely to develop RA, although the association were not significant. In the full adjusted model, the magnitude of association was decreased to 0.25 (95% CI: 0.06-1.05), but the significance was still not reached. Conclusion Analysing a comprehensive and large-scale population-based survey dataset (MEPS 2014) with adjustment for potential confounders suggested that receiving influenza vaccine did not increase the risk of RA and we have no evidence to suggest that influenza vaccination is not safe to be given to genetically predisposed individuals with RA. Further studies with more complete confounders, such as physical activity level and nutrition intake are strongly recommended. Disclosure N. Juber: None. A. Wannasri: None. T. Do: None.