SUCCESSFUL NUCLEIC-ACID BASED IMMUNIZATION OF NEWBORN CHIMPANZEES AGAINST HEPATITIS-B VIRUS

To determine whether DNA based immunization could protect newborn chim panzees against a challenge infection with hepatitis B virus, two chim panzees were immunized on the day of birth with a plasmid coding for h epatitis B surface antigen, and boosted at 6 and 24 weeks. Both animal s produced transient antibody to the hepatitis B surface antigen. Foll owing challenge with hepatitis B virus at 33 weeks the two immunized a nimals developed anamnestic antibody responses, however, neither devel oped detectable hepatitis B surface antigen or antibody to the core pr otein, the conventional markers of hepatitis B infection. Both of thes e markers appeared in an unimmunized control animal. We conclude that DNA based immunization can induce protective immunity in newborn chimp anzees. (C) 1997 Elsevier Science Ltd.