DNA vaccination against hepatitis E virus infection in cynomolgus macaques.
BACKGROUND
: The feasibility of DNA vaccination against hepatitis E in non-human primates has not been evaluated. In the present study a full-length hepatitis E virus (HEV) open reading frame (ORF)2 (Burmese strain) was assembled, cloned, and used for genetic immunization of cynomolgus macaques (cynos), which were subsequently challenged with a heterologous HEV strain (Mexico).


METHODS
: Four cynos were vaccinated intramuscularly with the HEV ORF2 DNA cassette and one animal was vaccinated with a mock DNA construct.


RESULTS
: Following vaccination anti-HEV antibodies were detected in the four HEV-DNA-vaccinated cynos, but not in the control animal. When challenged, two of the four HEV-DNA-vaccinated cynos were protected against HEV infection and had no elevated alanine aminotransferase activity, viremia, or fecal shedding. The two other DNA-vaccinated animals developed HEV infection and disease.


CONCLUSIONS
: These findings demonstrate the feasibility of DNA vaccination for the protection of HEV infection and warrant further studies to explore routes other than intramuscular for induction of a stronger and efficacious immune response.
Kamili
Saleem
S
Division of Viral Hepatitis, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. skamili@cdc.gov
Spelbring
John
J
Krawczynski
Krzysztof
K
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016751:Hepatitis E / Q000517:prevention & control*; D016752:Hepatitis E virus / Q000276:immunology; D008252:Macaca fascicularis; D019444:Vaccines, DNA; D014761:Viral Hepatitis Vaccines; D019562:Viral Load; D014764:Viral Proteins
D000914:Antibodies, Viral; C400971:ORF2 protein, Hepatitis E virus; D019444:Vaccines, DNA; D014761:Viral Hepatitis Vaccines; D014764:Viral Proteins