Study design

We conducted a sub study nested in clinicals trials. A subset of participants in the EBL2001, EBL2002 and EBL3001 trials in which HIV-negative participants received an active Ebola vaccine regimen consisting of Ad26.ZEBOV as dose 1 followed by MVA-BN-Filo as dose 2 [5–12]. All participants were HIV-negative. EBL2001 and EBL2002 were both phase 2 randomised, observer-blind, placebo-controlled studies in which participants received intramuscular injections of Ad26.ZEBOV, followed 28, 56 or 84 days later by MVA-BN-Filo. In the EBL2001 study (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT02416453","term_id":"NCT02416453"}}NCT02416453 and EudraCT 2015-000596-27), 18 to 65 years old healthy adults were included in the United Kingdom and France. The EBL2002 study (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT02564523","term_id":"NCT02564523"}}NCT02564523) was conducted in Burkina Faso, Cote d’Ivoire, Kenya and Uganda and enrolled three cohorts; 18 to 70 years old healthy adults, HIV infected adults, 12 to 17 years old adolescents and 6 to 11 years old children. The EBL3001 (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT02509494","term_id":"NCT02509494"}}NCT02509494) was a phase 3 double-blinded study which evaluated the safety and immunogenicity of the Ad26.ZEBOV (at day 0) and MVA-BN-Filo (at day 56) vaccine regimen in healthy adults, adolescents, children and toddlers in Sierra Leone.