Declining antibody levels after hepatitis B vaccination in Down syndrome: A need for booster vaccination?

Area of Science:

• Immunology
• Pediatrics
• Genetics

Background:

• Hepatitis B virus (HBV) infection is a significant global health concern.
• Vaccination is the primary method for preventing HBV infection.
• Down syndrome (DS) is associated with various health complications, potentially affecting immune responses.

Purpose of the Study:

• To determine the anti-HBs (antibody to Hepatitis B surface antigen) titer levels in children with Down syndrome (DS).
• To assess the adequacy of protective immunity against HBV in this population.
• To inform potential vaccination strategies for children with DS.

Main Methods:

• A cohort of 227 children of all ages with Down syndrome was studied.
• Anti-HBs titers were measured using serological assays.
• Statistical analysis was performed to evaluate titer levels and protective thresholds (≥10 IU/L).

Main Results:

• Only 48.1% of DS children aged 7-10 years and 31.9% of those older than 10 years had protective anti-HBs titers.
• The geometric mean anti-HBs titer was significantly lower in children with DS compared to expected levels.
• A substantial proportion of DS children did not achieve or maintain protective immunity against HBV.

Conclusions:

• Children with Down syndrome exhibit diminished antibody responses to HBV vaccination.
• Lower anti-HBs titers suggest a potential need for booster vaccinations in this vulnerable group.
• Further research into optimized HBV vaccination schedules for individuals with DS is warranted.