Kinetics and viral protein specificity of the cytotoxic t lymphocyte response in healthy adults immunized with live attenuated varicella vaccine

The cytotoxic T lymphocyte (CTL) response was evaluated in adults given live attenuated varicella vaccine, using target cells expressing varicella-zoster virus (VZV) immediate-early protein (IE62) or VZV glycoproteins gpl, gplV, or gpV to determine viral protein specificity. The frequency of CTL that recognized IE62 was 1:171,000 ± 46,000 SE in subjects tested 10 days to 8 weeks after the initial vaccine dose; the induction of CTL specific for gpl was equivalent. CTL recognition of VZV proteins was mediated by CD4⁺or CD8⁺cells. CTL recognition of lE62 and gplV persisted in vaccinees (tested -4 years later) and was comparable to that in the naturally immune. The mean frequency of CTL specific for gpV was lower (but not significantly) in vaccinees than in naturally immune subjects. Assay of responder cell frequencies showed persistence of equivalent numbers of T lymphocytes that recognized IE62 and gpl in vaccinees and naturally immune subjects. Immunization with this vaccine elicited memory T lymphocyte responses to VZV comparable to those induced by natural infection.