Immunization with Varicella-zoster virus glycoprotein E expressing vectors: Comparison of antibody response to DNA vaccine and recombinant vaccinia virus.

Immunization with DNA vaccines expressing Varicella-zoster virus (VZV) glycoprotein E (gE) induced formation of specific antibodies in mice. The antibody response correlated with the level of in vitro gE expression if the plasmid was inoculated intradermally (i.d.) with a gene gun but not if intramuscular (i.m.) injection was used. The i.d. vaccination produced a higher antibody level than the i.m. one even though a 100-fold amount of DNA was administered. A plasmid expressing a truncated form of gE was less immunogenic. The magnitude of antibody response induced by immunization with recombinant vaccinia viruses (rVVs) was equivalent to the gene gun vaccination. Administration of DNA by i.m. route or Vaccinia virus (VV) gE by i.d. mute resulted in predominance of IgG2a in the response while the gene gun plasmid inoculation usually elicited similar levels of IgG1 and IgG2a. The antibody response elicited by DNA vaccine was boosted by a secondary immunization with rVV. The boosting effect was highest if the virus was administered intraperitoneal (i.p.).