Immunogenicity of hepatitis B vaccine in healthy very low birth weight infants

Area of Science:

• Immunology
• Pediatrics
• Vaccinology

Background:

• Low birth weight infants are at increased risk of infections.
• Hepatitis B infection poses a significant health threat, especially to vulnerable infants.
• Optimizing vaccine schedules is crucial for protecting high-risk infant populations.

Purpose of the Study:

• To evaluate the immunogenic response to the hepatitis B vaccine in preterm infants based on birth weight.
• To determine the optimal timing for the first dose of hepatitis B vaccine in low birth weight infants.

Main Methods:

• Study included infants weighing <= 1500 gm, divided into two groups based on birth weight (<1000 gm and 1001-1500 gm).
• Infants received the hepatitis B vaccine at different ages: early (3 days) or at 1 month of age.
• Antibody titers to hepatitis B surface antigen (anti-HBs) were measured to assess response (defined as >10 mIU/ml).

Main Results:

• Infants receiving the first vaccine dose at 3 days of age had a response rate of 68%.
• Infants receiving the first vaccine dose at 1 month of age demonstrated a significantly higher response rate of 96%.
• This improved response at 1 month was observed irrespective of the infant's birth weight.

Conclusions:

• Administering the first dose of hepatitis B vaccine at 1 month of age is more effective for low birth weight infants.
• A delayed vaccination schedule enhances the immunogenicity of the hepatitis B vaccine in this vulnerable population.
• Optimizing the timing of hepatitis B vaccination is essential for achieving adequate protection in preterm infants.