Vaccine approaches with complete and partial efficacy in nonhuman primate models. Successful single platforms in a prime or prime-boost approach are pictured on the left, whereas combined platforms in a prime-boost approach are depicted on the right. Abbreviations: Ad, adenovirus; CMV, cytomegalovirus; EBOVΔVP30, Ebola virus lacking the gene for VP30; HPIV3, human parainfluenza virus type 3; MVA, modified vaccinia virus Ankara; RABV, rabies virus; VEEV, Venezuelan equine encephalitis virus; VLP, Ebola virus–like particles; VSV, vesicular stomatitis virus.