Primary Induction of Human CD8⁺Cytotoxic T Lymphocytes and Interferon‐γ–Producing T Cells after Smallpox Vaccination

Abstract

This study measured the ability of a standard smallpox vaccine, given by scarification (by bifurcated needle), to induce primary human vaccinia virus-specific cytotoxic and interferon (IFN)-gamma-producing T lymphocyte responses. Because protection against smallpox may be mediated in part by T cell memory responses induced by vaccination, an analysis of the induction of primary human cytotoxic T lymphocytes (CTL) and IFN-gamma-producing T cell responses was performed. Although smallpox is no longer an epidemic threat under natural conditions, vaccination is still recommended for persons working with vaccinia viruses in the laboratory and for those who may be at risk from the potential use of smallpox virus as a bioterrorism agent. The results demonstrate that smallpox vaccine given by bifurcated needle induces strong vaccinia virus-specific CD8(+) CTL and IFN-gamma-producing T cell responses and provide baseline information useful for planning the immunologic assessment of future smallpox vaccines.

Differential efficacy of vaccinia virus envelope proteins administered by DNA immunisation in protection of BALB/c mice from a lethal intranasal poxvirus challenge

“…The fact that poxviruses specifically modulate this cytokine suggests that IFN␥ might have an important role in developing a protective immune response. Recent studies with the live smallpox vaccine indicate that IFN␥ producing human T cell responses are a consistent marker after vaccination [21]. Our data suggest that IFN␥ production post-vaccination may prove to be an important correlate of immunity for any eventual subunit or DNA vaccine against OPV infection.…”

Recombinant modified vaccinia Ankara primes functionally activated CTL specific for a melanoma tumor antigen epitope in melanoma patients with a high risk of disease recurrence

“…16,42 Neither this study nor others employing recombinant poxviral vectors have achieved epitope-specific CTL, of the levels that are associated with acute viral infections. [43][44][45] . The likely mechanism for these 2 observations is the generation of poxviral-specific antibody and/or cellular immune responses during the vaccination schedule, either by neutralization of infection or by the generation of immunodominant CTL specific for epitopes encoded within the viral vector itself.…”

Clinical and immunologic responses to multiple doses of IMVAMUNE® (Modified Vaccinia Ankara) followed by Dryvax® challenge

“…The IFN-γ ELISPOT assays were performed, with modifications, as previously described [12,13]. Briefly, cryopreserved PBMCs were thawed, washed, plated (250,000 cells per well), and stimulated in triplicate using two levels of vaccinia virus at multiplicity of infection (MOI) of 1 and 2, for comparative purposes.…”