Recombinant vesicular stomatitis virus vector vaccines for WHO blueprint priority pathogens

Fathi, Anahita; Dahlke, Christine; Addo, Marylyn M.

After being vaccinated with a multi-component vaccine consisting of rVSV-ΔG-EBOV-, -MARV-and -SUDV-GP, macaques survived challenge with either of the respective species or TAFV. Monkeys challenged with MARV, EBOV or TAFV did not show clinical signs of disease, while those challenged with SUDV did. The authors argued that this observation could be due to slower replication kinetics of rVSVΔG-SUDV or the differential affinity of GP to antigen-presenting cells. They, therefore, tested a twostage vaccination administering rVSVΔG-SUDV two weeks prior to vaccination with rVSVΔG-EBOV and -MARV, which resulted in complete protection from challenge with no clinical evidence of infection both when challenged with SUDV and subsequently back challenged with MARV. 97 In another study, the rVSV-N4CT1 vector expressing either EBOV, SUDV or MARV GP from the first position of the rVSV genome was administered to macaques as a trivalent vaccine and none of the animals succumbed to the disease after challenge with any of the pathogens. However, a subset of vaccinated macaques did develop mild signs of disease as well as low levels of filovirus viremia, especially after challenge with EBOV, when this attenuated vector was used. 98 The same vector is currently employed in efforts to develop a multivalent vaccine candidate against MARV, SUDV, EBOV and additionally Lassa virus. 99