Immunization with the immediate-early tegument protein (open reading frame 62) of varicella-zoster virus protects guinea pigs against virus challenge

The IE62 protein, the primary regulatory protein of varicella-zoster virus (VZV) and the major component of the virion tegument, was an effective immunogen in the guinea pig model of VZV infection, whereas the ORF 29 gene product, a nonstructural DNA replication protein, did not elicit protection. All animals immunized with the ORF 29 protein had cell-associated viremia compared with 2 of 11 guinea pigs given the IE62 protein (P = 0.005). VZV was detected in ganglia from 38% of the animals given the ORF 29 protein and 44% of the control animals compared with 9% of the animals immunized with the IE62 protein (P = 0.04). In contrast to the IE62 protein, immunization with the ORF 29 protein did not prime the animals for an enhanced T-cell response upon challenge with infectious virus. The VZV IE62 protein has potential value as a vaccine component.