Safety and Immunogenicity of PCV20 in Pediatric Patients With Autoimmune Rheumatic Diseases

Safety and Immunogenicity of the 20-valent Pneumococcal Conjugate Vaccine (PCV20) in Children and Adolescents With Autoimmune Rheumatic Diseases

This clinical trial evaluates the immunogenicity (humoral and cellular) and safety of the 20-valent pneumococcal conjugate vaccine (PCV20) in children, adolescents, and young adults aged 2-25 years with autoimmune rheumatic diseases (ARDs). All participants will receive PCV20 according to prior vaccine history. Antibody titers, opsonophagocytic activity, cellular immune responses, and adverse events will be measured up to 6 months post-vaccination. Effects of immunosuppressive therapy and physical activity levels related vaccine response will also be assessed.

ARD patients are at higher risk of pneumococcal infections due to disease-related and therapy-induced immunosuppression. Despite vaccination recommendations, immunogenicity data for PCV20 in ARD pediatric populations are lacking. This prospective phase IV study will enroll 85 patients aged 2-25 years diagnosed with juvenile idiopathic arthritis (JIA), juvenile systemic lupus erythematosus (jSLE), and juvenile dermatomyositis (JDM). All will receive PCV20 per CDC guidance. Blood samples will be collected at baseline (D0), 4 weeks (D28), and 6 months (D180). The functional opsonophagocytic activity (OPA) for specific serotypes will be analyzed. Safety will be monitored through adverse event diaries, clinical evaluations, and disease activity indices. Physical activity will be evaluated by validated questionnaires and via accelerometry.

Inclusion Criteria:

• Age 2-25 years
• Diagnosis of JIA, jSLE, or JDM by validated classification criteria
• Clinically stable
• Informed consent/assent

Exclusion Criteria:

• Acute infection or fever at vaccination
• Severe allergic reaction to vaccine components
• Recent blood transfusion (<6 months)
• Other vaccine within 4 weeks prior at the time of inclusion
• Pregnancy or breastfeeding
• Prior PCV20