Vaccination and Immunoprophylaxis in Infants

1. Initial Postnatal Intervention

Hepatitis B Vaccine:

• The Hepatitis B vaccine should be administered to infants within the first 12 hours after birth.
• The first dose of the vaccine is critical for controlling the virus transmitted from the mother.

Hepatitis B Immunoglobulin (HBIG):

• Hepatitis B immunoglobulin (HBIG) should be administered to infants born to HBsAg-positive mothers at the same time as the vaccine.
• HBIG provides passive protection until the infant's immune system is fully developed.
• HBIG should be administered in a different injection site after birth (a different arm or leg than the vaccine).

2. Vaccination Schedule

Hepatitis B Vaccination Schedule for Infants According to the Ministry of Health Recommendation

Hepatitis B vaccination in infants is administered in a total of 5 doses according to the national vaccination schedule:

• 1st Dose: Administered within the first 12 hours after birth.
• 2nd Dose: Administered in the 2nd month after birth as part of the hexavalent combination vaccine.
• 3rd Dose: Administered in the 4th month after birth as part of the hexavalent combination vaccine.
• 4th Dose: Administered at 6 months after birth as part of the hexavalent combination vaccine.
• 5th Dose: Administered at 18 months after birth as part of the hexavalent vaccine.

3. Newborn Follow-up

Infants should be tested after completing the vaccination schedule to assess their immune response.

• HBsAg and anti-HBs antibody levels should be checked at 9-12 months of age. It should be noted that tests performed before 9 months of age (if IG was used) may be falsely positive.

Results:

• Anti-HBs ≥10 mIU/mL: Indicates that the infant has responded to the vaccine and is protected.
• Anti-HBs <10 mIU/mL: Indicates that the infant is not protected; in this case, the vaccine can be administered again.

4. Approach Based on Risk Status

HBsAg-Negative Mothers:

• The routine Hepatitis B vaccination program is administered to newborns.
• HBIG is not required.

HBsAg-Positive Mothers:

• Both Hepatitis B vaccination and HBIG are administered.
• These measures are vital to reduce the risk of transmission after birth.

If the Mother's HBsAg Status is Unknown:

• Hepatitis B vaccine is administered immediately after birth.
• If the mother tests HBsAg positive, HBIG is administered as soon as possible (preferably within the first 7 days).

5. Breastfeeding

• There is no harm in breastfeeding for mothers who are Hepatitis B carriers, but the baby must receive the postpartum vaccine and HBIG.
• If there are cracks or bleeding at the nipple, it should be noted that the mother needs appropriate treatment due to the risk of transmission.

6. Premature Infants

Premature infants (birth weight <2000 grams) may have a lower immune response. A special vaccination protocol should be followed for these infants:

• There is no contraindication for breastfeeding by mothers who are Hepatitis B carriers, but the baby must receive the postnatal vaccine and HBIG.
• The first dose administered at birth may be ineffective, so an additional dose is required.
• An immunity test should be performed after the doses are completed.

7. The Importance of Immunization

• Passive Immunity (HBIG): Used to prevent viral transmission during birth.
• Active Immunity (Vaccination): Provides long-term protection.

8. Additional Recommendations

• Family Screening and Vaccination: Other family members of mothers who are Hepatitis B carriers should also be screened and vaccinated if necessary.
• Education and Information: The mother should be informed about the importance of adhering to the infant's immunization schedule and the safety of vaccines.