Preclinical evaluation of a two-dose vaccination schedule of recombinant Hansenula polymorpha hepatitis B vaccine in animals.
OBJECTIVE
The current 3-dose regimen of hepatitis B vaccination for infants requiring over 6 mo period may pose the poor rate of compliance and later protection from hepatitis B virus (HBV) infection. This preclinical study is to investigate the feasibility of reducing the number of doses of hepatitis B (HB) vaccine.


RESULTS
Eight groups of guinea pigs immunized with two doses of HP-HB vaccines at either 0 and 4 weeks or 0 and 8 weeks elicited geometric titers (GMT) of anti-HBs similar to that of four groups immunized with three doses of controls. The overall GMT of anti-HBs were not significantly different between the E- and C-groups (p>0.05) of monkeys. Specifically, the anti-HBs titers in the C-group reached the peak of 24857 (938.3-104585) mIU/mL one week after the 3rd dose, which were statistically higher than those of the E-group. However, they were reduced to comparable levels of anti-HBs in the E-group during weeks 9-12, suggesting comparable immune response of both vaccination regimens.


METHODS
Twelve groups of guinea pigs (four animals in each group) were immunized with 2 experimental recombinant yeast Hansenula Polymorpha derived HB vaccines (HP-HB vaccine) and 2 commercial recombinant yeast Saccharomyces Cerevisiae vaccines (Temrevac-HB) as controls at 0, 4 and 8 weeks, 0 and 4 weeks, and 0 and 8 weeks respectively. Each guinea pig received 2 µg vaccine. Twelve Cynomolgus monkeys were randomly divided into two groups (six animals in each group). Animals in the experimental group (E-group) were injected with two doses of pilot produced 20 µg HP-HB vaccine. Animals in the control group (C-Group) were immunized with three doses of 10 µg Temrevac-HB. Both vaccines were administered at an interval of 3 weeks for monkeys.


CONCLUSIONS
The 2-dose regimen of the HP-HB vaccine has comparable HBV immune responses as the 3-dose regimen of Temrevac-HB vaccine in Cynomolgus monkeys.
Microbiology Department and Infectious Disease Center; School of Basic Medical Sciences; Peking University Health Science Center; Beijing, P.R. China; Vaccine Research Department II; Beijing Tiantan Biological Products Co., Ltd.; Beijing, P.R. China.
Jin
J
Li
Deyou
D
Zhang
Rui
R
Ma
Xuqin
X
Yang
Xi
X
Wang
Caimei
C
Li
Sucai
S
Zhang
Hesheng
H
Xue
Kai
K
Zhao
Hui
H
Zhuang
D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D008252:Macaca fascicularis; D008297:Male; D023421:Models, Animal; D010843:Pichia / Q000235:genetics; D014611:Vaccination / Q000379:methods*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic
2-dose regimen; Cynomolgus monkey; Hansenula Polymorpha-derived vaccine; Vaccine; hepatitis B