CAdVax-EBO7 protects cynomolgus macaques against both ZEBOV and SEBOV challenge

GroupaVaccineInitial challengebBack-challengebClinical findingscOutcome
VirusS/T (%)VirusS/T (%)
Group 1EBO7/M8ZEBOV5/5 (100)No clinical signsAll survived
Control AMockZEBOV0/1 (0)F, D, A, moderate P, V (d3, 4.3; d5, 6.8), T, LE↑↑↑Succumbed on day 6
Group 2EBO7/M8SEBOV5/5 (100)No clinical signsAll survived
Control BMockSEBOV0/1 (0)D, A, mild P, V (d7, 6.1; d10, 6.7), T, LE↑↑Succumbed on day 10
Group 2EBO7/M8ZEBOV5/5 (100)No clinical signsAll survived
Control CMockZEBOV0/1 (0)F, D, A, mild P, V (d5, 3.7; d7, 5.4), T, LE↑↑↑Succumbed on day 9
  • a Group 1 macaques were vaccinated on days 0 and 65 with 1 × 1010 PFU each of EBO7 and M8 and then challenged on day 106 with ZEBOV. Group 2 macaques were vaccinated on days 0 and 120 with 1 × 1010 PFU each of EBO7 and M8 and then challenged on day 162 with SEBOV. Control macaques (A, B, and C) were vaccinated with 2 × 1010 PFU of HC4.

  • b Based on back-titration, group 1 and control A were challenged with 500 PFU of ZEBOV, group 2 and control B were challenged with 800 PFU of SEBOV, and group 2 was back-challenged with 1,100 PFU of ZEBOV along with control C. In addition to these controls, historical control macaques (n = 20 for ZEBOV, and n = 10 for SEBOV) were used to limit the number of controls. S/T, number of survivors/total number challenged.

  • c Clinical findings: fever (F) was defined as a rectal temperature increase of more than 2°C over baseline; depression (D) and anorexia (A) were assessed subjectively; petechia (P) was defined as mild (barely visible), moderate (visible over focal areas) or widespread; viremia (V) was defined as detectable virus in the serum, with the day (d) of detection and log10 value in PFU/ml shown in parentheses; thrombocytopenia (T) was defined as a ≥35% decrease in platelets; and elevated levels of liver-associated enzymes (LE) were defined as a 2- to 3-fold increase (↑), a 4- to 5-fold increase (↑↑), or a more-than-5-fold increase (↑↑↑) in serum aspartate aminotransferase and alanine aminotransferase over baseline.