Ebola outbreaks in Guinea and DRC draw rapid response

The WHO has announced the rapid deployment of staff, medical equipment and vaccines following the emergence of new Ebola cases in Guinea and the Democratic Republic of Congo (DRC).

The outbreak in Guinea marks the first time the disease has been reported there since the last major West Africa outbreak, which had started in that country and ended in 2016.

The re-emergence of Ebola comes just as countries in Africa prepare to receive first major consignments of COVID-19 vaccines through the Gavi and WHO-led COVAX Facility. The swift response highlights concerns that transmission of Ebola across borders could unleash a dangerous clash of infectious disease outbreaks and overwhelm weak and under-staffed healthcare systems across the region.

Yet despite the alarm, rapid actions to reinforce surveillance, contact tracing, testing, and treatment, which were already well underway last week, show that national authorities and WHO teams now have considerable expertise and experience to draw on. This is due to the significant capacity building and preparedness planning that took place during the previous major outbreak in 2014-2016.

The consignment of 11,000 doses of Ebola vaccine from the WHO arrived in Guinea on 23 February, and immunisations are expected to begin imminently. The WHO separately announced that a further 8,500 doses would soon be shipped from the US and 8,000 vaccine doses already stocked in DRC were being used to immunise people at high risk in that country. The prompt response is indicative of a beefed-up arsenal of new healthcare products now available to fight the disease.

The WHO has released USD1.25 million to support the response in Guinea and to strengthen surveillance and preparedness in neighbouring Cote d'Ivoire, Guinea-Bissau, Liberia, Mali, Senegal and Sierra Leone. The United Nations Central Emergency Response Fund has also disbursed USD15 million to support the response.

The epicentre of this latest outbreak in Guinea is in a border area of the country, as was the situation at the start of the last major outbreak in 2014, when infections moved across land borders to Sierra Leone and Liberia. Consequently, authorities in those neighbouring countries were quick to announce increased vigilance and the WHO is also co-ordinating with officials in Cote d'Ivoire, Mali, Senegal and other countries at risk in the sub-region.

Although the WHO has not confirmed the name of the Ebola vaccine deployed, IHS Markit believes that Ervebo (rVSV-ZEBOV-GP), an injectable single-dose vaccine manufactured by Merck Sharp & Dohme (MSD, US), will play the lead role, since the WHO has recently announced the establishment of a global Ebola vaccine stockpile to ensure swift outbreak responses, starting with supplies of the MSD vaccine. Ervebo was initially approved by the European Medicines Agency (EMA) in November 2019. Since then, the product has also been approved by the US Food and Drug Administration (FDA), as well as in eight African countries. It has also secured pre-qualification by the WHO, allowing it to be fast-tracked by national regulatory agencies for urgent deployment.

Other new products could also potentially be at the disposal of national and international teams tasked with preventing a repeat of the 2014-2016 outbreak. In July 2020, Janssen Pharmaceuticals (subsidiary of Johnson & Johnson [J&J], US) became the second pharmaceutical company to be granted marketing authorisation by the EMA for an Ebola vaccine - its regimen of Zabdeno (Ad26. ZEBOV) and Mvabea (MVA-BN-Filo) administered eight weeks apart. Prior to its European authorisation, the two-dose vaccine was used in DRC to complement the use of Ervebo as part of a major clinical trial to generate data in a real-world setting.

On the therapies front, Regeneron Pharmaceuticals (US) received US FDA approval in October 2020 for Inmazeb (atoltivimab, maftivimab, and odesivimab-ebgn), comprising a cocktail of three monoclonal neutralising antibodies, for the treatment of infections caused by Zaire ebolavirus after clinical trials demonstrated its superiority compared with other investigational agents - ZMapp (Mapp Biopharmaceutical, US) and remdesivir (Gilead Sciences, US) - in terms of mortality. Inmazeb was provided under a compassionate use protocol during a 2018 Ebola outbreak in DRC. Regeneron stated at the time of final approval by the FDA that it would continue to provide Inmazeb on a not-for-profit basis for outbreaks in the DRC and that it was working with non-governmental organizations and public health agencies to ensure continued access in low- and middle-income countries.

Although reported numbers of confirmed novel coronavirus infections in the Africa region are proportionately low, accounting for only 3% of the cumulative number of confirmed cases globally, the pandemic has already placed significant pressure on under-staffed and ill-equipped health facilities in many locations. Failure to interrupt transmission of Ebola could unleash a dangerous clash of infectious disease outbreaks and overwhelm weak healthcare systems in West Africa. However, the swift response is testament to how much better prepared authorities are to deal with Ebola this time round. The capacity for surveillance, testing, and contact tracing is far more robust, and newly available vaccines, along with an approved new cocktail of monoclonal neutralising antibodies from Regeneron, have dramatically enhanced the tools at hand to fight the virus.

Posted 23 February 2021 by Sacha Baggili, Research Analyst, Life Sciences