Recombinant vaccine against hepatitis E: dose response and protection against heterologous challenge.
Thirty-two rhesus monkeys were used to evaluate the dose response of a recombinant HEV vaccine, and the efficacy of the vaccine based on the ORF2 protein of the Pakistani strain for pre- and post-exposure vaccination against intravenous challenge with homologous or heterologous virus was examined. Post-exposure vaccination did not protect animals against hepatitis. Although primates vaccinated twice with 50-microgram, 10-microgram, 2-microgram, or 0.4-microgram doses of the recombinant 55 kDa ORF-2 protein were infected, they were protected from hepatitis when they were challenged with very high doses of the homologous strain of HEV. Primates vaccinated twice with a 50 micrograms dose of the recombinant protein were protected from hepatitis after heterologous challenge with the Mexican strain, the strain of HEV most genetically distant from the Pakistani strain.
Tsarev
S A
SA
Hepatitis Viruses Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Tsareva
T S
TS
Emerson
S U
SU
Govindarajan
S
S
Shapiro
M
M
Gerin
J L
JL
Purcell
R H
RH
D000818:Animals; D004305:Dose-Response Relationship, Drug; D016751:Hepatitis E / Q000517:prevention & control*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D008252:Macaca fascicularis; D008253:Macaca mulatta; D016366:Open Reading Frames; D014614:Vaccines, Synthetic / Q000627:therapeutic use*; D014761:Viral Hepatitis Vaccines / Q000627:therapeutic use*; D014764:Viral Proteins / Q000276:immunology
D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines; D014764:Viral Proteins