SummaryBackgroundIn March, 2016, a flare-up of Ebola virus disease was reported in Guinea, and in response ring vaccination with the unlicensed rVSV-ZEBOV vaccine was introduced under expanded access, the first time that an Ebola vaccine has been used in an outbreak setting outside a clinical trial. Here we describe the safety of rVSV-ZEBOV candidate vaccine and operational feasibility of ring vaccination as a reactive strategy in a resource-limited rural setting.MethodsApproval for expanded access and compassionate use was rapidly sought and obtained from relevant authorities. Vaccination teams and frozen vaccine were flown to the outbreak settings. Rings of contacts and contacts of contacts were defined and eligible individuals, who had given informed consent, were vaccinated and followed up for 21 days under good clinical practice conditions.FindingsBetween March 17 and April 21, 2016, 1510 individuals were vaccinated in four rings in Guinea, including 303 individuals aged between 6 years and 17 years and 307 front-line workers. It took 10 days to vaccinate the first participant following the confirmation of the first case of Ebola virus disease. No secondary cases of Ebola virus disease occurred among the vaccinees. Adverse events following vaccination were reported in 47 (17%) 6–17 year olds (all mild) and 412 (36%) adults (individuals older than 18 years; 98% were mild). Children reported fewer arthralgia events than adults (one [<1%] of 303 children vs 81 [7%] of 1207 adults). No severe vaccine-related adverse events were reported.InterpretationThe results show that a ring vaccination strategy can be rapidly and safely implemented at scale in response to Ebola virus disease outbreaks in rural settings.FundingWHO, Gavi, and the World Food Programme.

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Understanding risk factors for Ebola transmission is key for effective prediction and design of interventions. We used data on 860 cases in 129 chains of transmission from the latter half of the 2013–2016 Ebola epidemic in Guinea. Using negative binomial regression, we determined characteristics associated with the number of secondary cases resulting from each infected individual. We found that attending an Ebola treatment unit was associated with a 38% decrease in secondary cases (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI): 0.38, 0.99) among individuals that did not survive. Unsafe burial was associated with a higher number of secondary cases (IRR = 1.82, 95% CI: 1.10, 3.02). The average number of secondary cases was higher for the first generation of a transmission chain (mean = 1.77) compared with subsequent generations (mean = 0.70). Children were least likely to transmit (IRR = 0.35, 95% CI: 0.21, 0.57) compared with adults, whereas older adults were associated with higher numbers of secondary cases. Men were less likely to transmit than women (IRR = 0.71, 95% CI: 0.55, 0.93). This detailed surveillance data set provided an invaluable insight into transmission routes and risks. Our analysis highlights the key role that age, receiving treatment, and safe burial played in the spread of EVD.

Introduction : Cette étude avait pour objectif d’identifier les facteurs ayant influencé la faible performance du projet d’Observatoire communautaire sur l’accès aux services de santé (Ocass) pendant sa mise en œuvre, de 2014 à 2017 en Guinée et de formuler des recommandations pour la suite du projet. Méthodes : Il s’agissait d’une étude qualitative utilisant le cadre de performance multipolaire de B. Marchal et al. , adapté du Modèle d’évaluation globale et intégrale de la performance des systèmes de santé (Egipss), du cadre de Sicotte. Les données ont été collectées à l’aide d’une feuille de calcul Excel ® développée conformément aux quatre fonctions du cadre d’analyse : prestation des services, atteinte des buts, interaction avec l’environnement et sauvegarde des valeurs et la culture organisationnelle. Résultats : L’absence d’une évaluation initiale des capacités techniques, opérationnelles et organisationnelles de l’organe de mise en œuvre et la non-prise en compte des besoins spécifiques du projet en termes de ressources (financières, matérielles et humaines) ont été déterminantes dans la faible performance de l’Ocass. La faible implication des acteurs nationaux, l’épidémie d’Ebola et la multiplicité des acteurs autour de l’Observatoire ont également joué un grand rôle dans la non-atteinte de l’objectif du projet. Conclusion : Notre étude a révélé que la prise en compte du contexte national dans la mise en place de projet de responsabilité sociale est essentielle. La réalisation d’une évaluation de base demeure quant à elle demeure une étape fondamentale pour garantir son succès.