Vaccination Wth Virus-Like Particles Protects Mice From Ebola

NEW YORK (Reuters Health) - Vaccination with Ebola virus-like particles (eVLPs) can completely protect mice from a subsequent challenge with the virus, according to a report published in the December 8th early edition of the Proceedings of the National Academy of Sciences.

"Our data suggest that eVLPs may represent a promising vaccine candidate for protection against Ebola virus infections and a much needed tool to examine the genesis and nature of immune responses to Ebola virus," note senior author Dr. Sina Bavari, from the US Army Medical Research Institute of Infectious Disease in Frederick, Maryland, and colleagues.

Infection with Ebola virus carries a mortality rate of up to 80%. Although only natural outbreaks have occurred thus far, it is conceivable that the virus could be used as a biological warfare agent. Despite the obvious need for protection, efforts to generate an Ebola vaccine have met with limited success.

Ebola VLPs are spontaneously produced when Ebola virus glycoprotein and matrix protein are expressed together in mammalian cells. In previous studies, vaccination with similar particles has proven effective in protecting against HIV, papillomavirus, parvovirus, and rotavirus.

In the current study, Dr. Bavari's team tested the immunogenicity of eVLPs in vitro and in mice. Treatment with eVLPs caused the maturation and activation of dendritic cells, as indicated by changes in cell-surface markers and cytokine secretion, the authors report.

In mice, eVLP vaccination produced CD4+ and CD8+ T cell activation and induced neutralizing antibodies against Ebola virus. Most importantly, vaccinated animals were protected against subsequent lethal challenge with the virus.

"This article provides the groundwork for future studies to evaluate the efficacy of VLPs for both Marburg virus and Ebola virus," the investigators conclude.

Source: Proc Natl Acad Sci USA 2003. [ Google search on this article ]

MeSH Headings: Viral Vaccines