Prevention of Ebola virus disease through vaccination: where we are in 2018

The Lancet
Sep 01, 2018 Volume 392 Number 10149 p711-794
https://www.thelancet.com/journals/lancet/issue/current

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Prevention of Ebola virus disease through vaccination: where we are in 2018
Yves Lévy, Clifford Lane, Peter Piot, Abdul Habib Beavogui, Mark Kieh, Bailah Leigh, Seydou Doumbia, Eric D’Ortenzio, Claire Lévy-Marchal, Jerome Pierson, Deborah Watson-Jones, Vinh-Kim Nguyen, Heidi Larson, Julia Lysander, Christine Lacabaratz, Rodolphe Thiebaut, Augustin Augier, David Ishola, Stephen Kennedy, Geneviève Chêne, Brian Greenwood, James Neaton, Yazdan Yazdanpanah
[Excerpts]
In 2016, Guinea, Liberia, and Sierra Leone succeeded in interrupting the longest epidemic of Ebola virus disease in global history.

Control of the epidemic was primarily achieved by implementation of effective and coordinated public health measures that involved rapid identification, isolation of cases, contact tracing, and isolation of contacts. However, the risk of re-emergence of Ebola virus disease is real, as shown by the 2017 and 2018 outbreaks in the Democratic Republic of the Congo. Consequently, along with other public health measures, efforts to develop an effective vaccine against Ebola virus disease must continue.

As of June 18, 2018, 36 completed trials, seven active and not recruiting, and seven recruiting Ebola vaccine studies are registered on ClinicalTrials.gov. The only study that has been able to provide data on clinical efficacy is the Ebola Ça Suffit vaccination trial in Guinea…o build on the vaccine research studies that have been done thus far, the outstanding questions on the rapidity and durability of the immune response in adults, safety and immunogenicity in children, and the nature of the responses in immunocompromised and pregnant individuals using different vaccine strategies must be addressed. Improved understanding of humoral and cellular immune responses to Ebola vaccines is needed to identify correlates of protection. Answering these questions will require improvement of global capacity to continue research on Ebola vaccines, and collaborative partnerships are needed to optimise the chances of success. Several Ebola vaccine clinical trials in Africa, North America, and Europe have been done using such partnerships, including the EBOVAC projects, the Ebola Ça Suffit vaccination trial consortium, STRIVE, and PREVAIL…

…Against this backdrop, the Partnership for Research on Ebola Vaccinations (PREVAC) was established as an international consortium, including research and academic institutions (the French Institute for Health and Medical Research [Inserm], London School of Hygiene & Tropical Medicine, the US National Institutes of Health, and the Universities of Bordeaux and Minnesota), health authorities and scientists from four Ebola-affected countries (Guinea, Liberia, Sierra Leone, and Mali), non-governmental organisations (the Alliance for International Medical Action and Leidos) and pharmaceutical companies (MSD, Johnson & Johnson, and Bavarian Nordic). This partnership was built to focus on Ebola research activities to prevent or respond effectively to the next potential Ebola outbreak. This consortium is currently conducting a randomised, double-blind, placebo-controlled trial of three Ebola vaccine strategies in adults and children (aged ≥1 year): (1) rVSV-ZEBOV prime without boost; (2) rVSV-ZEBOV prime followed by a rVSV-ZEBOV boost; and (3) Ad26.ZEBOV prime followed by MVA-BN-Filo boost. As of June, 2018, more than 2350 adults and children have been recruited, and an additional 2500 enrolments are planned to achieve the target enrolment.

In summary, it is important to investigate different scenarios for vaccination strategies and different vaccines to respond more effectively to future outbreaks. These strategies include contact and post-exposure vaccination, targeted preventive vaccination, and widespread preventive vaccination of at-risk populations such as health-care workers and those residing in areas of recurrent outbreaks.