Antigenic breadth: a missing ingredient in HSV-2 subunit vaccines?

[severe combined immunodeficiency]

The successful human papillomavirus and hepatitis B virus subunit vaccines contain single viral proteins that represent 22 and 12 %, respectively , of the antigens encoded by these tiny viruses . The herpes simplex virus 2 (HSV-2 ) genome is >20 times larger . Thus , a single protein subunit represents 1 % of HSV-2 's total antigenic breadth . Antigenic breadth may explain why HSV-2 glycoprotein subunit vaccines have failed in clinical trials , and why live HSV-2 vaccines that express 99 % of HSV-2 's proteome may be more effective . I review the mounting evidence that live HSV-2 vaccines offer a greater opportunity to stop the spread of genital herpes , and I consider the unfounded 'safety concerns ' that have kept live HSV-2 vaccines out of U .S . clinical trials for 25 years .