Blood transfusion called priority Ebola therapy

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Treating Ebola patients with blood or purified serum of disease survivors should be a priority in the fight against the outbreak in West Africa, an expert panel organized by the World Health Organization (WHO) said on 5 September. The recommendation came at the end of a two-day meeting to determine which experimental Ebola therapies and vaccines should be prioritised for accelerated clinical development. The WHO estimates that roughly 3,700 people have been infected in West Africa, and about 1,850 have died. Marie-Paule Kieny, WHO assistant director-general for health systems and innovation, told reporters that the transfusion of whole blood or purified serum from Ebola survivors was the therapy with the greatest potential to be implemented immediately on a large scale in West Africa — in part because the outbreak’s size means there are many potential donors available. The idea is to transfer antibodies against Ebola from survivors to sufferers, but there is little information on the efficacy of such transfusions. The priority, said Kieny, will be to ensure that collected blood is free of other pathogens and that health-care workers remain safe during transfusions, when they are exposed to Ebola patients’ blood. Efforts to institute proper infrastructure and training are in place are already beginning, she added. No Ebola therapies or vaccines have been approved for human use, but a WHO expert panel said on 11 August that testing and using experimental drugs and vaccines in the outbreak is ethically acceptable provided that every effort is made to gather scientific data on safety and efficacy. That panel said that such actions are justified because of the exceptional nature of this outbreak; for example, it has proven difficult to implement public health measures that have ended past Ebola outbreaks. At the WHO meeting that concluded today, experts also recommended prioritising tests of two candidate vaccines: a chimpanzee adenovirus vaccine (ChAd3) developed by the US National Institute of Allergy and Infectious Diseases (NIAID) and Glaxo SmithKline, and a recombinant vesicular stomatitis virus (rVSV) vaccine developed by the Public Health Agency of Canada and licensed to NewLink Genetics and Profectus Biosciences. Phase I trials of ChAd3 will start this month in the United States, the United Kingdom, Gambia and Mali. The first tests will be on healthy volunteers because areas stricken by Ebola lack infrastructure to do proper trials.

Both the ChAd3 and rVSV vaccines have conferred 100% protection against Ebola in animal studies. The WHO estimates that 800 doses of rVSV are currently available, and some 15,000 doses of ChAd3 should be ready by the end of the year. The WHO has also selected drugs for priority use and testing, basing its decision on those that have shown good efficacy and safety in non-human primates. The chosen treatments include ZMapp, a cocktail of monoclonal antibodies which last week was shown to confer 100% protection in rhesus macaques. On 2 September, the US Department of Health and Human Services announced up to US$42.3 million in funding over 18 months for the drug’s development and manufacturing. Oyewale Tomori, a virologist at Redeemer’s University in Redemption City, Nigeria, says that efforts to test and distribute new therapies and vaccines must not detract from the need to institute basic public health measures in Ebola-stricken areas or to provide supportive care for patients. Few patients in outbreak areas have access to quality care, such as intravenous rehydration, that can greatly reduce mortality. But WHO said on 28 August that it was seeking $490 million to bolster basic public health measures and quality of care in Ebola treatment centres.

Nature doi:10.1038/nature.2014.15854 Nature Original web page at Nature

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