Clinical evaluation to determine the appropriate paediatric formulation of a tick-borne encephalitis vaccine

Area of Science:

• Pediatric Vaccinology
• Immunology
• Public Health

Background:

• Tick-borne encephalitis (TBE) poses a significant public health risk, particularly in endemic regions.
• Vaccination is a primary strategy for preventing TBE, but optimal dosing in pediatric populations requires investigation.
• FSME-IMMUN is an established vaccine for TBE prevention.

Purpose of the Study:

• To determine the optimal antigen dose of a pediatric FSME-IMMUN vaccine formulation for children and adolescents.
• To evaluate the safety and immunogenicity of the pediatric FSME-IMMUN vaccine in the target age group.
• To compare the immunogenicity of the pediatric formulation in adolescents with that of the adult formulation.

Main Methods:

• Conducted two dose-finding studies and one open-label safety study.
• Enrolled 3697 children and adolescents aged 1-15 years.
• Assessed seroconversion and seroprotective rates following primary vaccination series.

Main Results:

• The 1.2 microg antigen dose was identified as optimal, demonstrating high seroconversion rates.
• Adolescents (12-15 years) receiving the 1.2 microg dose achieved seroprotective rates comparable to adults (16-35 years) on the 2.4 microg dose.
• The pediatric FSME-IMMUN formulation exhibited a favorable safety profile.

Conclusions:

• The 1.2 microg dose of the pediatric FSME-IMMUN vaccine is safe and highly immunogenic for children and adolescents.
• This optimal pediatric dose provides robust protection across the 1-15 year age range, including adolescents.
• The findings support the use of the pediatric FSME-IMMUN formulation for effective TBE prevention in younger populations.