Abstract: Objective To prepare the oral solution of egg yolk hepatitis B virus (HBV)-specific transfer factor (EYHBV-TF) and
evaluate its immunological activity as an immune regulator against hepatitis B. Methods From hens immunized with the
Hepatitis B vaccine the egg yolk was isolated to extract the specific transfer factor EYHBV-TF, and its physicochemical
properties were examined. Leukocyte adhesion inhibition test (LAI) was performed to detect the immunogenic activity of
EYHBV-TF. The solution of EYHBV-TF was then administered orally in normal mice, and the specific cellular immune activity
induced was assayed with delayed type skin hypersensitivity test (DTH), with the non-specific immune activity assessed with
immune organ index. The immune responses induced by oral EYHBV-STF solution were compared with those by EYHBV-STF
injection and by different dosages (injection and oral) of porcine spleen HBV-specific transfer factor (PSHBV-STF), porcine
spleen nonspecific transfer factor, and egg yolk extracts from non-immunized hens. Results The prepared EYHBV-STF oral
solution, which met the standards for biological products, could inhibit leukocyte adhesion in vitro and significantly enhance
mouse foot pad swelling, demonstrating its capability of transferring antigen-specific delayed type hypersensitivity reactions
to naive recipient. EYHBV-STF oral solution also significantly improved the immune organ index in mice (P<0 01) with similar
effects to those caused by EYHBV-STF injections and by PSHBV-STF injection and oral solution. Conclusion Orally
administered EYHBV-STF and EYHBV-STF injection both possess hepatitis B antigen-specific cellular immune activity and can
significantly enhance specific cellular immune responses.