It remains to be determined whether pre-existing immunity to HSV-1 will impact the immunogenicity of the HSV-2 ΔgD−/+gD−1 vaccine as was shown with the gD subunit vaccine (Stanberry et al., 2002) This may be less of a problem with HSV-2 ΔgD−/+gD−1 as it elicits a polyantigenic response whereas infection primarily elicits Abs to gD as evidenced by the immunoblots. The gene discussed is PAEP; the disease is infection.