Therapeutics: Zaire ebolavirus glycoprotein

Studies in non-human primates suggest Ebola vaccines based on highly attenuated recombinant vesicular somatitis virus (rVSV) vectors could help prevent infection without the post-vaccination viremia of RVSV-EBOV. In viral kinetic and plaque formation assays, two vaccines based on highly attenuated versions of the rVSV vector used in RVSV-EBOV and encoding the same Zaire ebolavirus glycoprotein antigen as RVSV-EBOV decreased viral growth and plaque size compared with RVSV-EBOV. In an NHP model of lethal Ebola viral challenge, intramuscular inoculation with either of the highly attenuated vaccines prevented infection in all immunized animals and decreased post-vaccination viremia by about tenfold compared with RVSV-EBOV. Next steps could include testing the vaccine in NHPs challenged with additional strains of Ebola virus.

Merck & Co. Inc. and NewLink Genetics Corp. have RVSV-EBOV (rVSV-EBOV; rVSV-ZEBOV-GP; VSV-EBOV; VSV-ZEBOV; BPSC1001) in Phase II/III testing...