First of all I wish you and your new baby the best of health.
From a standpoint of Halacha their is no problem receiving an injection containing or derived from non-Jewish blood and their is no reason to decline neither the vaccine nor the immunoglobulin.
Additionally from a medical standpoint it is VERY important that you follow the doctors advice and administer both injections as well as further booster shots to the baby. If the proper procedures are not followed, your baby has a 95% chance of developing chronic hepatitis B! If these two medications are given correctly within the first 12 hours of life, a newborn has more than a 90% chance of being protected against a lifelong hepatitis B infection. You must make sure your baby receives the second and third dose of the hepatitis B vaccine at one and six months of age to ensure complete protection. People infected with chronic Hepatitis B have a 40% lifetime risk of death from cirrhosis or cancer of the liver. Furthermore extensive medical research has shown only minimal risk of minor complications from the treatment, with even minor discomfort such as chills and diarrhea being uncommon. While your low viral load may significantly reduce the risk of infection, the remaining possibility would still be at least a safek sakana which obligates one to violate even a Torah law. In this circumstance there is absolutely no violation under consideration, and the Torah obligates one to follow accepted medical advice and procedures to insure one's health.