A Modern Approach to Live Vaccines: Recombinant Poxviruses

A technique for preparing live recombinant vaccines is described. The technique is a blend of old and new technologies. Vaccinia virus, used for almost two hundred years in the immunoprophylaxis of smallpox, has been engineered by recombinant DNA technologies to express foreign genetic information derived from heterologous pathogens. This recombinant live vaccine virus has been shown to elicit important immunological responses to these foreign antigens on inoculation of the recombinant virus into animals. Significantly, a number of studies have shown that vaccination of laboratory animals with these recombinant viruses results in protecting these animals against disease on subsequent challenge with the heterologous infectious agent. Vaccinia virus recombinants expressing the influenza virus hemagglutinin, the herpes simplex virus glycoprotein D, the hepatitis B virus surface antigen, the rabies virus glycoprotein, and a malarial parasite antigen are described and the biological properties of these recombinant viruses as live immunogens are detailed. A brief description of the problems and future prospects is included.