Chimeric alphavirus vaccine candidates protect mice from intranasal challenge with western equine encephalitis virus

Academic Article


  • We developed two types of chimeric Sindbis virus (SINV)/western equine encephalitis virus (WEEV) alphaviruses to investigate their potential use as live virus vaccines against WEE. The first-generation vaccine candidate, SIN/CO92, was derived from structural protein genes of WEEV strain CO92-1356, and two second-generation candidates were derived from WEEV strain McMillan. For both first- and second-generation vaccine candidates, the nonstructural protein genes were derived from SINV strain AR339. Second-generation vaccine candidates SIN/SIN/McM and SIN/EEE/McM included the envelope glycoprotein genes from WEEV strain McMillan; however, the amino-terminal half of the capsid, which encodes the RNA-binding domain, was derived from either SINV or eastern equine encephalitis virus (EEEV) strain FL93-939. All chimeric viruses replicated efficiently in mammalian and mosquito cell cultures and were highly attenuated in 6-week-old mice. Vaccinated mice developed little or no detectable disease and showed little or no evidence of challenge virus replication; however, all developed high titers of neutralizing antibodies. Upon intranasal challenge with high doses of virulent WEEV strains, mice vaccinated with ≥105 PFU of SIN/CO92 or ≥104 PFU of SIN/SIN/McM or SIN/EEE/McM were completely protected from disease. These findings support the potential use of these live-attenuated vaccine candidates as safe and effective vaccines against WEE. © 2009 Elsevier Ltd. All rights reserved.
  • Published In

  • Vaccine  Journal
  • Digital Object Identifier (doi)

    Author List

  • Atasheva S; Wang E; Adams AP; Plante KS; Ni S; Taylor K; Miller ME; Frolov I; Weaver SC
  • Start Page

  • 4309
  • End Page

  • 4319
  • Volume

  • 27
  • Issue

  • 32