Live-attenuated measles, mumps, and rubella booster vaccine in children diagnosed with rheumatic disease: A single-center study.

To evaluate the safety profile of measles, mumps and rubella (MMR) booster in children diagnosed with rheumatic diseases receiving biological agents. The study included retrospective safety data of children administered MMR booster dose receiving biologics or biologics with methotrexate. The files of 182 patients were accessed from the pediatric rheumatology biological therapy archive, and the vaccination status of these children was obtained by accessing electronic records. Of 182 patients, 14 patients were vaccinated with MMR booster dose. Thirteen of the patients were followed up with a diagnosis of juvenile idiopathic arthritis and one with colchicine-resistant familial Mediterranean fever. None of the patients had disease exacerbation after vaccination, and three patients had mild side effects consisting of rash, angioedema, joint pain, and fatigue.    Conclusion: This study supports the data regarding evidence of the safety of MMR booster dose administration in children with rheumatic diseases receiving bDMARDs. What is Known: • MMR booster is avoided in immunocompromised pediatric patients receiving bDMARDs except in specific conditions. What is New: • The MMR booster dose may be safe in children with PedRD receiving bDMARDs or bDMARDs with MTX. These bullets can be added to the manuscript.