Protection provided by a recombinant ALVAC®-WNV vaccine expressing the prM/E genes of a lineage 1 strain of WNV against a virulent challenge with a lineage 2 strain

J. M. Minke, L. Siger, L. Cupillard, B. Powers, T. Bakonyi, S. Boyum, N. Nowotny, R. Bowen

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30 Citations (Scopus)


The emergence of lineage 2 strains of WNV in Europe as a cause of clinical disease and mortality in horses raised the question whether the existing WNV vaccines, all based on lineage 1 strains, protect against circulating lineage 2 strains of WNV. In the present paper we have determined the level of cross protection provided by the recombinant ALVAC®-WNV vaccine in a severe challenge model that produces clinical signs of WNV type 2 disease. Ten horses were vaccinated twice at 4 weeks interval with one dose of the ALVAC-WNV vaccine formulated at the minimum protective dose. A further 10 horses served as controls. Two weeks after the second vaccination, all horses were challenged intrathecally with a recent neurovirulent lineage 2 strain of WNV. The challenge produced viraemia in 10 out of 10 and encephalitis in 9 out of 10 control horses. Three horses had to be euthanized for humane reasons. In contrast, none of the vaccinated horses developed WNV disease and only 1 vaccinated horse became viraemic at a single time point at low titre. The prevalence of WNV disease and viraemia were significantly lower in the vaccinated horses than in the control horses (P

Original languageEnglish
Pages (from-to)4608-4612
Number of pages5
Issue number28
Publication statusPublished - Jun 20 2011



  • Cross protection
  • Horse
  • Intrathecal challenge
  • Recombinant ALVAC®-WNV vaccine
  • WNV lineage 1 and 2

ASJC Scopus subject areas

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

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