Already, the experimental drug ZMapp, developed by Mapp, a small biopharmaceutical firm in the US, has been used to treat at least seven patients – four of them Westerners – and has shown promising results in trials on primates. Stocks have now run out, but Mapp has been handed $25m (£15m) by the US government to scale up production.
On Friday, the WHO met in Geneva to assess the options but concluded that despite the extraordinary measures, "new treatments or vaccines are not expected for widespread use before the end of 2014".
As well as the GSK/NIH vaccine, to be tested in healthy volunteers in Oxford within two weeks, a Canadian vaccine has also shown promise and is being tested in the US.
Professor Hill explained that the GSK/NIH vaccine, which is based on a strain of chimpanzee cold virus and known as ChAd3, was originally developed in the US for potential use against a bio-terror attack – and only existed because of high levels of funding allocated to vaccines designated for defence.
Asked why a fully tested and licensed vaccine had not been developed, Professor Hill said: "Well, who makes vaccines? Today, commercial vaccine supply is monopolised by four or five mega- companies – GSK, Sanofi, Merck, Pfizer – some of the biggest companies in the world.
"The problem with that is, even if you've got a way of making a vaccine, unless there's a big market, it's not worth the while of a mega-company …. There was no business case to make an Ebola vaccine for the people who needed it most: first because of the nature of the outbreak; second, the number of people likely to be affected was, until now, thought to be very small; and third, the fact that the people affected are in some of the poorest countries in the world and can't afford to pay for a new vaccine. It's a market failure."
He said that producing a vaccine for Ebola was "technically more doable" than making one for other challenging and more widespread diseases such as TB, HIV and malaria, which receive more funding. "There's a lesson here," he said. "If we had invested in an Ebola vaccine, had it sitting there as the outbreak comes, you could have nipped it in the bud, been able to vaccinate the region where it started. What happened in Guinea was that it got out of control and spread. If you invest in having a relatively small amount of vaccine, available in the right place, as soon as anything happens, you could save huge amounts of money, not to mention lives."
In the wake of the outbreak, governments should now work with the pharmaceutical industry to push through development of vaccines against "outbreak diseases" such as Ebola, as well as Sars, Marburg and Chikungunya, Professor Hill said, with the goal of establishing stockpiles in vulnerable countries.
In a trial in primates infected with Ebola, a single dose of ChAd3 protected all 16 animals. The human trials involve 60 healthy Britons and 80 healthy people in Mali and the Gambia. GSK is already fast-tracking development of the vaccine and hopes to have 10,000 doses available by the end of the year. If proved safe and effective, it would be given to health workers in the Ebola-hit countries. Hundreds have died in the current outbreak, and many are now refusing to come to work.
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