Assessment of Immune Response to Hepatitis B Vaccine: Comparison of Novel Polycaprolactone Blend Microparticles Based Hepatitis B Vaccine and Alum Based Vaccine

The study reports on the development of a novel hepatitis b vaccine prepared by physically mixing smaller microparticles (8-12 μm; blend PCL-PLGA; containing equivalent to 10μg HBsAg) with larger microparticles (12-20 μm; blend PCL-PLA; entrapping 10μg HBsAg). The vaccine was reconstituted with alum adsorbed HBsAg (equivalent to 10μg HBsAg) and was injected in BALB/c mice subcutaneously as single dose (Total 30 μg HBsAg). The generated immune responses in mice was investigated by Enzyme Linked Immunosorbate Assay (ELISA) technique and was compared with the response generated with alum based vaccine (control group) injected three times at 0, 4, 24 weeks in mice (Total 30 μg HBsAg). The peak antibody titer (4.6491 ± 1.20) generated by vaccine formulation (test group) after single injection were comparable to the control group (4.9099 ± 0.78). The titers sustained in both test & Control groups during 25 week study period. However, at the end of 25th week the titers were slightly higher for control group. The study has shown the feasibility of blend polymeric microparticles as vaccine carrier.