Boosting immune response with a candidate varicella-zoster virus glycoprotein subunit vaccine

A varicella-zoster virus (VZV) seropositive individual was immunized with 100 micrograms of purified VZV TgpI-511 glycoprotein subunit antigen formulated with monophosphoryl lipid A. Serum samples were obtained during a 40-day period post-immunization (PI) and analysed by immunoprecipitation and virus neutralization tests. The results from immunoprecipitation studies revealed an increase in VZV anti-gpI antibody titer as early as 6 days PI which continued to rise during 40 days PI. In addition, virus neutralization tests showed a 21.0% VZV neutralization 6 days PI with an increase to a 96.7% VZV neutralization 40 days PI. These results suggested that the candidate VZV glycoprotein subunit vaccine (TgpI-511) was capable of boosting the production of neutralizing antibodies in the immunized VZV seropositive human subject.