Large-scale Ebola vaccine trial to start in Liberia | Science| In-depth reporting on science and technology | DW | 23.01.2015
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Large-scale Ebola vaccine trial to start in Liberia

GlaxoSmithKline (GSK) has announced that it's shipped the first doses of its Ebola vaccine to Liberia. The experimental vaccine will be administered along with another vaccine candidate in the first large-scale trials.

Pharmaceutical giant GlaxoSmithKline (GSK) expects to deliver the first batch of its experimental Ebola vaccine to Liberia today. Comprising 300 vials, the vaccine shipment will be the first to arrive to a country seriously affected by Ebola, GSK said in a statement.

The US National Institutes of Health, or NIH, hopes to administer the vaccine as one of two in a double-blind trial in Liberia. Of 27,000 hoped-for subjects, one-third would receive the GSK vaccine, one-third would receive a different vaccine candidate, and one-third would be injected with a placebo.

Neither those administering nor receiving the injection will know what they are getting. "It's the gold standard of determining whether a vaccine works," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), an NIH sub-agency that co-developed the vaccine candidate with Okairos, a GSK biotech subsidiary.

The Liberia study, which Fauci said combines phases II and III of standard trials, could last from nine months to a year. It will especially target those at high risk, including frontline healthcare workers and "contact tracers," who attempt to track down the source of the virus.

The first participant receives a dose of the NIAID/GSK Ebola vaccine in Bethesda, Maryland, on September 2 (Photo: NIAID)

Phase III trials will use the higher dosage to assure the most predictive protection

The NIAID-Okairos vaccine uses a chimpanzee cold virus to introduce inert Ebola genetic material into the human immune system. Humans don't catch the chimp cold virus, and the Ebola material delivered in the vaccine cannot cause Ebola.

"It's a modern style of vaccine, using recombinant DNA technology - you use only the particular protein," Fauci told DW.

NIAID at the end of last November had announced positive results from phase I trials of the vaccine. In a peer-reviewed study, each half of a group of 20 volunteers who had received differing doses of the vaccine were shown to have developed an immune response, without any serious adverse side effects.

"The size and quality of the CD8 T-cell response we saw in this trial are similar to that observed in non-human primates vaccinated with the candidate vaccine," said Julie E. Ledgerwood, the principal investigator in the trial.

GSK stated that it intends to follow up Friday's delivery with further shipments of the vaccine to Liberia.

"Shipping the vaccine today is a major achievement and shows that we remain on track with the accelerated development of our candidate Ebola vaccine," said GSK Global Vaccines Chairman Moncef Slaoui.

Scientists at the National Microbiology Lab in Winnipeg, Manitoba, prepare an experimental Ebola vaccine (Photo: REUTERS/Public Health Agency of Canada)

Scientists at the National Microbiology Lab in Winnipeg, Manitoba, worked on the other experimental Ebola vaccine

Of the 8,626 Ebola deaths recorded by the World Health Organization (WHO) since the outbreak began last year, 3,605 of them have been in Liberia. In the past three weeks, WHO data has indicated 25 new cases in Liberia.

Generally, however, the organization has said that case incidences continue to decline in all of the three heavily affected countries: Guinea, Liberia and Sierra Leone.

Sierra Leone, with 10,340 total cases and 3,145 deaths in the ongoing outbreak, will also see a clinical trial, which the US Centers for Disease Control will begin in February.

Mali was declared Ebola-free as of January 18.

The other Ebola vaccine candidate to be tested in Liberia was developed by the Public Health Agency of Canada with support from the US Department of Defense, and is undergoing further development by NewLink Genetics and drug maker Merck. It should be delivered to Liberia within the next week, Fauci said.

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