Experimental Hepatitis B Vaccine Aims to Prevent HBV Reinfection after Living Donor Liver Transplantation

After a person with hepatitis B receives a liver transplant, hepatitis B virus (HBV) usually reinfects the new liver unless the patient uses prophylactic therapy. This typically involves administration of hepatitis B immune globulins (HBIG) and the standard HBV vaccine to the transplant recipient.

But, according to a group of German researchers writing in the August 2007 Journal of Viral Hepatitis, adoptive transfer of HBV immunity with the liver after vaccination of a living liver donor could be a new approach to preventing reinfection in the recipient.
The time to achieve HBV immunity in living donors is usually short (1-2 months). Therefore, the investigators established a short-time immunization protocol (4 injections at 2-week intervals) using Hepimmune, a recombinant vaccine that contains the L, M, and S proteins of HBV.

They examined cellular and humoral immune responses after immunization with Hepimmune, and compared the vaccine's immunogenicity to that of a standard HBV vaccine containing only the S protein (HBVAXPRO).

Results

• HBV-specific T-cells were detectable in the Hepimmune group after the second injection and in the standard vaccine group after the third injection.

• Interferon-gamma production by T-cells was significantly higher after the third injection of Hepimmune (P < 0.001).

• Proliferative responses were also significantly higher in the Hepimmune group after the second to fourth injections (P < 0.01).

• The humoral (antibody-based) immune response could already be detected after the first injection in 9 of 15 Hepimmune recipients, while it was barely distinguishable in recipients of the standard vaccine.

• Titres of the 2 vaccines differed significantly following all 4 vaccine injections (P < 0.01).

Conclusion

Based on these findings, the researchers concluded that, "Hepimmune appears to be a good candidate for short time immunization protocols."

08/28/07

Reference
A Schumann, M Fiedler, U Dahmen, and others. Cellular and humoral immune response to a third generation hepatitis B vaccine. Journal of Viral Hepatitis 14(8): 592-598. August 2007.