Hepatitis B immune globulin is an immune globulin (IgG) rich in IgG antibodies against hepatis B. IgG is a normal component of breastmilk. No special precautions are required during breastfeeding. Hepatitis B immune globulin is recommended along with hepatitis B vaccine to be given to infants of mothers who are positive for hepatitis B surface antigen. No differences exist in infection rates between breast-fed and formula-fed infants born to hepatitis B-infected women, as long as the infant receives these preventative measures at birth.[1] Mothers with hepatitis B are encouraged to breastfeed their infants after their infants receive these preventative measures.[2,3] Holder pasteurization (62.5 degrees C for 30 minutes) decreases the concentration of endogenous immunoglobulin G by up to 79%.[4,5] A study of 67 colostrum samples that underwent Holder pasteurization found that IgG amounts decreased by 34 to 40%.[6] None of the studies measured IgG activity.