The best ref is the Pediatric Red Book.  It is published by the AAP and
outlines the standard of care for infectious diseases situations.  The
latest edition was published approximately 2 y ago.

In Hep B the baby should receive the Immunoglobulin within the first 12
hours of life and initiate the vaccine series.  Depending on brand of
vaccine used the doses vary to provide adequate protection.  Under these
circumstances the baby will be protected and mom can breastfeed safely.

Maryelle