Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial

摘要: Summary Background A recombinant, replication-competent vesicular stomatitis virus-based vaccine expressing a surface glycoprotein of Zaire Ebolavirus (rVSV-ZEBOV) is promising Ebola candidate. We report the results an interim analysis trial rVSV-ZEBOV in Guinea, west Africa. Methods For this open-label, cluster-randomised ring vaccination trial, suspected cases virus disease Basse-Guinee (Guinea, Africa) were independently ascertained by response teams as part national surveillance system. After laboratory confirmation new case, clusters all contacts and defined randomly allocated 1:1 to immediate or delayed (21 days later) with (one dose 2 × 10 7 plaque-forming units, administered intramuscularly deltoid muscle). Adults (age ≥18 years) who not pregnant breastfeeding eligible for vaccination. Block randomisation was used, varying blocks, stratified location (urban vs rural) size rings (≤20 >20 individuals). The study open label masking participants field time possible, but workers unaware allocation Taking into account incubation period about 10 days, prespecified primary outcome laboratory-confirmed onset symptoms at least after randomisation. per protocol compared incidence vaccinated individuals clusters. This registered Pan African Clinical Trials Registry, number PACTR201503001057193. Findings Between April 1, 2015, July 20, 90 clusters, total population 7651 people included planned analysis. 48 these (4123 people) assigned rVSV-ZEBOV, 42 (3528 rVSV-ZEBOV. In group, there no symptom randomisation, whereas group 16 from seven showing efficacy 100% (95% CI 74·7–100·0; p=0·0036). No diagnosed vaccinees groups 6 post-vaccination. At cluster level, inclusion adults, effectiveness 75·1% −7·1 94·2; p=0·1791), 76·3% −15·5 95·1; p=0·3351) everyone (eligible vaccination). 43 serious adverse events reported; one event judged be causally related (a febrile episode participant, which resolved without sequelae). Assessment ongoing. Interpretation indicate that might highly efficacious safe preventing disease, most likely effective level when delivered during outbreak via strategy. Funding WHO, support Wellcome Trust (UK); Medecins Sans Frontieres; Norwegian Ministry Foreign Affairs through Research Council Norway; Canadian Government Public Health Agency Canada, Institutes Research, International Development Centre, Department Affairs, Trade Development.