PRECLINICAL EFFICACY OF A PROTOTYPE DNA VACCINE - ENHANCED PROTECTIONAGAINST ANTIGENIC DRIFT IN INFLUENZA-VIRUS

Vaccination with plasmid DNA expression vectors encoding foreign prote ins elicits antibodies and cell-mediated immunity and protects against disease in animal models. We report a comparison of DNA vaccines, usi ng contemporary human strains of virus, and clinically licensed (inact ivated virus or subvirion) vaccines in preclinical animal models, to b etter predict their efficacy in humans. Influenza DNA vaccines elicite d antibodies in both non-human primates and ferrets and protected ferr ets against challenge with an antigenically distinct epidemic human in fluenza virus more effectively than the contemporary clinically licens ed vaccine. These studies demonstrate that DNA vaccines may be more ef fective, particularly against different strains of virus, than inactiv ated virus or subvirion vaccines.