Mireia Lopez Corbeto*, Irene Torrecilla Martínez, Estefanía Moreno Ruzafa, Laia Martínez Mitjana, José Ángel Rodrigo Pendás, Xavier Martínez Gómez
Immune-mediated Pediatric Rheumatic Diseases (IMPRD) is potentially serious diseases that can lead to a significant decrease in the child's quality of life. The use of immunosuppressive therapies necessary in IMPRD may contribute to an increased risk of infections. The objective is to describe the prevalence of susceptibility to vaccine-preventable diseases and the immunogenicity and safety of vaccines in patients with IMPRD. A prospective cohort study included 36 pediatric patients with an IMPRD who visited a large tertiary hospital. Pre-vaccination serological tests were performed, and a vaccination plan was developed for each patient. Blood samples were collected for study of the post-vaccination seroprotection when needed. Follow-up was performed to analyze the safety of the vaccines: local and systemic reactions were evaluated during 28 days after vaccination, while detection of flares was reviewed until 3 months after. The vaccination schedule was not completed in 6 patients (16.7%). A total of 146 vaccines were administered with a median of 2 vaccines per child and visit. Overall seroprotection rates at the inclusion were higher than 80%, being the highest proportion in varicella (94.5% (95CI%: 81.9-98.5)) and the lowest in hepatitis B (47.2% (95% CI: 32.0-63.0)). Seroprotection rate after vaccination was higher than 90% for all vaccines. There were 15 local and 1 systemic adverse events after vaccination. No flares were observed. Vaccination is safe and overall immunogenic in this population. We recommend assessing vaccination requirements in IMPRD as soon as their diagnosis is made.