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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
114
0.5 mL intramuscular dose containing polysaccharide conjugates for 20 pneumococcal serotypes (PCV20, Prevenar 20) vaccine will be administered intramuscularly in 1 dose in patients with ARDs and healthy controls.
Seroconversion Rate After Vaccination
Will be defined as ≥2-fold increase in IgG titers for ≥50% of serotypes.
Time frame: Day 0 to Day 28 and through 180 days
Opsonophagocytic Antibody Titers (OPA)
Blood samples will be collected at three time points: before the first dose (D0), 4 weeks after the first dose (D28), and six months after the final dose (D180). Functional opsonophagocytic anticapsular antibodies will be quantified using 6 validated serotype-specific opsonophagocytic activity (OPA) assays. Results will be expressed as geometric mean titers (GMTs) for each serotype and the percentage of participants reaching titers equal to or above the lower limit of quantification (LLOQ).
Time frame: Day 0 to Day 28 and through 180 days
Safety Assessment
Safety will be closely monitored, and all serious adverse events will be classified as related or unrelated to the vaccine. A standardized adverse event diary will be provided to all patients and healthy controls for recording local and systemic reactions during the 4 weeks after first dose. Local reactions include: injection site pain, redness, swelling, bruising, itching, and induration. Systemic reactions include: fever, fatigue, chills, malaise, drowsiness, loss of appetite, nausea, vomiting, diarrhea, abdominal pain, dizziness, tremors, headache, fatigue, myalgia, muscle weakness, arthralgia, pruritus, and skin rash.
Time frame: Day 1 through Day 28
Impact of PCV20 vaccination on Disease Activity on patients with JIA
To evaluate the impact of PCV20 vaccination on clinical disease activity in patients with JIA, measured using JADAS27, higher scores indicate greater disease activity. Unit of Measure: Score (0-57)
Time frame: Day 1 through Day 28
Impact of PCV20 vaccination on Disease Activity on patients with JSLE
To evaluate the impact of PCV20 vaccination on clinical and laboratory disease activity in patients with juvenile systemic lupus erythematosus (jSLE), assessed using the SLEDAI-2K. The score incorporates clinical and laboratory manifestations of lupus, with higher scores indicating greater disease activity. Unit of Measure: Score (range 0-105)
Time frame: Day 1 through Day 28
Impact of PCV20 vaccination on Disease Activity on patients with JDM
To evaluate the impact of PCV20 vaccination on clinical and laboratory disease activity in patients with juvenile dermatomyositis (JDM), assessed using the Childhood Myositis Assessment Scale (CMAS). The CMAS evaluates muscle function and endurance, with higher scores indicating better muscle strength and physical performance. Unit of Measure: Score (range 0-52)
Time frame: Day 1 through Day 28
Influence of Immunosuppressive Treatment
To assess the short- and long-term influence of immunosuppressive treatment on the response to PCV-20 vaccination in patients with ARDs compared to healthy controls.
Time frame: Day 0 to Day 180
Seroconversion Rates after PCV20 vaccination by Physical Activity Classification
Proportion of participants who achieve seroconversion defined as at least a twofold increase in pneumococcal serotype-specific IgG antibody concentrations compared to baseline at Days 28 and 180 following PCV20 vaccination. Participants will be categorized as physically active or inactive based on World Health Organization criteria using validated methods.
Time frame: Day 1 to 180 post-vaccination
Geometric Mean Titers of Pneumococcal Antibodies after PCV20 Vaccination by Physical Activity Classification
Geometric mean titers of pneumococcal serotype-specific IgG antibodies will be quantified using multiplex Luminex assay at Days 28 and 180 after PCV20 vaccination. Participants will be classified as physically active or inactive according to the World Health Organization criteria, based on validated methods.
Time frame: Day 1 to 180 post-vaccination
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