Ottawa researcher Dr. Heather L. Davis has become a pioneer in the development of DNA-based vaccines. With her collaborators in France and Germany Davis found that introducing the DNA code for the envelope protein of the hepatitis B virus into the muscle tissue of mice prompted a strong and sustained immune response. She believes that DNA-based vaccines could prove to offer many advantages over conventional vaccines, not least of which are greater safety and effectiveness and reduced cost. She has also begun to explore the potential of DNA-based vaccines for use in the treatment of disease. In recent experiments Davis and colleagues in France have successfully used DNA vaccination to cure transgenic mice of a chronic hepatitis B carrier state.