What is the follow-up protocol for an infant exposed to Hepatitis B (HBV)?

From the Guidelines

For an infant exposed to hepatitis B, follow-up care should include completion of the hepatitis B vaccine series and testing for infection status, with post-vaccination serologic testing recommended at 9-12 months of age to confirm immunity and rule out infection, as per the recommendations of the Advisory Committee on Immunization Practices 1.

Key Recommendations

• Infants born to HBsAg-positive mothers should receive HepB vaccine and HBIG within 12 hours of birth, administered at different injection sites, and complete the vaccine series according to the recommended schedule, with the final dose not administered before age 24 weeks (164 days) 1.
• Post-vaccination serologic testing should include hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) to verify immunity, with testing not performed before age 9 months to avoid detection of passive anti-HBs from HBIG administered at birth 1.
• HBsAg-negative infants with anti-HBs levels ≥10 mIU/mL are protected and need no further medical management, while those with anti-HBs levels <10 mIU/mL should be revaccinated with a single dose of HepB vaccine and receive post-vaccination serologic testing 1-2 months later 1.

Follow-up Protocol

• Regular well-child visits should continue to monitor overall health and development, with particular attention to liver function and potential complications of hepatitis B infection 1.
• Infants who are HBsAg-positive should be referred for appropriate follow-up and management to prevent long-term complications of hepatitis B infection 1.

Breastfeeding

• Infants born to HBsAg-positive mothers may be breastfed beginning immediately after birth, as the risk of hepatitis B transmission through breast milk is considered low when proper prophylaxis is administered 1.

From the FDA Drug Label

For an infant with perinatal exposure to an HBsAg-positive and HBeAg-positive mother, a regimen combining one dose of Hepatitis B Immune Globulin (Human) at birth with the hepatitis B vaccine series started soon after birth is 85%–95% effective in preventing development of the HBV carrier state. Hepatitis B Immune Globulin (Human) (0. 5 mL) should be administered intramuscularly (IM) to the newborn infant after physiologic stabilization of the infant and preferably within 12 hours of birth. Hepatitis B Vaccine should be administered IM in three doses of 0. 5 mL of vaccine (10 μg) each. The first dose should be given within 7 days of birth and may be given concurrently with Hepatitis B Immune Globulin (Human) but at a separate site.

The follow-up for an infant exposed to hepatitis B includes:

• Administering Hepatitis B Immune Globulin (Human) at birth
• Starting the hepatitis B vaccine series soon after birth
• Key components of the follow-up regimen:
  • One dose of Hepatitis B Immune Globulin (Human) at birth
  • Hepatitis B vaccine series:
    • First dose within 7 days of birth
    • Second dose 1 month after the first
    • Third dose 6 months after the first
• Effectiveness: 85%–95% effective in preventing development of the HBV carrier state 2 2

From the Research

Follow-up for Infant Exposed to Hepatitis B

• The follow-up for an infant exposed to hepatitis B typically involves a combination of passive and active immunization, including the administration of hepatitis B immune globulin (HBIG) and hepatitis B vaccine 3, 4.
• The immunization schedule for infants born to hepatitis B surface antigen (HBsAg)-positive mothers typically consists of providing newborns with protection at birth with HBIG, followed by three doses of hepatitis B vaccine administered at 0,1, and 6 months of life 5.
• Studies have shown that combined active-passive immunization of newborns against hepatitis B provides persistent protection up to adolescence, despite a frequent waning of anti-HBs antibodies 5.
• The use of HBIG is recommended for infants born to HBsAg-positive mothers to prevent perinatal exposure to hepatitis B virus (HBV) 3, 4.
• However, administration of HBIG with hepatitis B vaccine can delay and reduce responses to the vaccine, regardless of the site of administration 6.

Risk Factors for Mother-to-Infant Transmission

• The risk factors for mother-to-infant transmission of HBV include positivity for hepatitis B e antigen (HBeAg) and high viral load of the mothers 7.
• Understanding the mechanisms of mother-to-infant transmission is essential for the interruption of HBV transmission 7.
• Despite passive-active immunoprophylaxis, up to 8-10% of newborns still acquire HBV infection, highlighting the need for continued research and improvement of prevention strategies 7.

Immunization and Follow-up

• The immunization schedule and follow-up for infants exposed to hepatitis B should be based on the latest recommendations and guidelines, taking into account the individual risk factors and circumstances 5, 3, 4.
• Blood samples should be obtained after immunization, at 2 years of age, and biennially thereafter to test for HBsAg and hepatitis B surface and core antibodies (anti-HBs, anti-HBc) 5.