Smallpox vaccine with integrated IL-15 demonstrates enhanced in vivo viral clearance in immunodeficient mice and confers long term protection against a lethal monkeypox challenge in cynomolgus monkeys

Rafal J. Zielinski, Jeremy Smedley, Pin Yu Perera, Peter M. Silvera, Thomas A. Waldmann, Jacek Capala, Liyanage P. Perera

Research output: Contribution to journalArticle

13 Scopus citations


Despite the eradication of smallpox, there is heightened concern that it could be reintroduced as a result of intentional release of Variola major virus through an act of bioterrorism. The live vaccine that was pivotal in the eradication of smallpox though considered a gold standard for its efficacy still retains sufficient residual virulence that can cause life-threatening sequelae especially in immune deficient individuals. Therefore, a safer smallpox vaccine that can match the efficacy of first generation vaccines is urgently needed. We previously reported that the integration of human IL-15 cytokine into the genome of Wyeth strain of vaccinia (Wyeth/IL-15), the same strain as the licensed vaccine, generates a vaccine with superior immunogenicity and efficacy in a mouse model. We now demonstrate that Wyeth/IL-15 is non-lethal to athymic nude mice when administered intravenously at a dose of 107 plaque forming units and it undergoes enhanced in vivo clearance in these immune deficient mice. Furthermore, a majority of cynomolgus monkeys vaccinated with vaccinia viruses with integrated IL-15, when challenged 3 years later with a lethal dose of monkeypox virus displayed milder clinical manifestations with complete recovery supporting the utility of Wyeth/IL-15 for contemporary populations as a safer and efficacious smallpox vaccine.

Original languageEnglish (US)
Pages (from-to)7081-7091
Number of pages11
Issue number43
Publication statusPublished - Oct 8 2010
Externally publishedYes



  • IL-15
  • Monkeypox
  • Smallpox vaccine

ASJC Scopus subject areas

  • Molecular Medicine
  • Immunology and Microbiology(all)
  • veterinary(all)
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

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