DNA vaccines for prophylactic or therapeutic immunization against hepatitis B.

DNA-based or genetic vaccination is an efficient new technique to stimulate specific immune responses after in vivo delivery of bacterial plasmids encoding antigens. In mice and in various other animal models for hepadnavirus infection, DNA vaccines specific for hepatitis B virus (HBV) antigens induce a strong humoral and cell-mediated immunity that confers protection in some models. Although there are effective prophylactic vaccines already available for HBV, there is currently no effective treatment for chronic HBV infection. Patients with HBV-associated liver disease are at increased risk of developing hepatocellular carcinoma and would greatly benefit from the availability of a therapeutic vaccine against HBV. By inducing immune responses closely related to those involved in clearing virus from the host, DNA vaccines may represent an alternative therapeutic approach for chronic HBV infection.