Is 1121B Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use 1121B? Is 1121B safe for nursing mother and child? Does 1121B extracts into breast milk? Does 1121B has any long term or short term side effects on infants? Can 1121B influence milk supply or can 1121B decrease milk supply in lactating mothers?

No information is available on the clinical use of 1121B during breastfeeding. Because 1121B is a large protein molecule with a molecular weight of about 147,000, the amount in milk is likely to be very low and absorption is unlikely because it is probably destroyed in the infant's gastrointestinal tract. Until more data become available, 1121B should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. The manufacturer recommends that breastfeeding be discontinued during 1121B therapy. 1121B is a human immunoglobulin G1 (IgG1) antibody. Holder pasteurization (62.5 degrees C for 30 minutes) decreases the concentration of endogenous immunoglobulin G in mature milk by 60 to 79%.[1][2] A study of 67 colostrum samples that underwent Holder pasteurization found that IgG amounts decreased by 34 to 40%. Specific IgG subclasses decreased by different amounts, with IgG1 activity decreasing by about 37%.[3] None of the studies measured IgG activity.