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Why the Ebola vaccine is still years away

The Ebola virus.
The Ebola virus.

With this Ebola epidemic burning on in West Africa — and with no vaccine or cure yet on the market — there has been a lot of discussion about speeding up the drug testing and approval process to get therapies to patients faster.

Just this week, the drug company GlaxoSmithKline announced it will take the unprecedented step of starting mass production on a vaccine that has only just begun being tested in humans. That news followed the WHO's groundbreaking decision that it's ethical to try unproven and experimental treatments on people in this public health emergency.

Some have said that this focus and push to discover Ebola therapies might be the silver lining of this epidemic. The companies who make Ebola drugs have said they will do all they can to bring their therapies — if effective — to those who need them. But the reality is that the road to market is a long, tedious, and lined with failure.

What it takes to bring a drug to market

Getting a drug or vaccine to market in the US generally follows this pathway:


So the intervention needs to go through three phases of clinical trials in people. But before testing it humans, researchers backing the drug or treatment first need to hand over really promising data from animal studies to the FDA and get the regulator's approval to start recruiting patients. That's called the "pre-clinical" phase of drug development. It can take a few years, and for every 5,000 compounds discovered at this stage, only about five are allowed to be tried in humans.

If that happens, the researchers need to find hundreds and then thousands of volunteers to participate in clinical trials: in the first phase, they check for safety in a small group of healthy people to make sure the drug isn't immediately making anyone sick or worse, and to figure out how much of the drug people can tolerate.

Then, in a larger group of participants, they test to make sure the treatment actually delivers on its promise and monitor how well it works against the best-available therapies or a placebo. The third phase involves an even bigger group — up to 3,000 people — and, again, researchers compare how the drug works against other treatments on the market and carefully analyze safety data.

This entire drug development process takes an average of 12 years,  and it costs between $100 million and $1 billion.

If the drug makes it through phase three, the data are submitted to the FDA for approval. Only one in five therapies make it this far, and it usually takes the FDA a couple of years to consider the data and bring the drug to market, if it so chooses.

The US has some of the most stringent standards in the world when it comes to getting new medicines to people, and for this reason, the overwhelming majority of promising drugs in animal studies never even make it to phase one trials, let alone past all the regulatory hurdles.

This entire drug development process takes an average of 12 years, and costs between $100 million and $1 billion.

This Ebola crisis may speed up the process

For its part, GSK is already starting to manufacture an Ebola vaccine that only has promising animal studies behind it, but hasn't even been fully tested in humans. The company has said it'll have 10,000 doses stockpiled should the science for the vaccine check out. But it's only in phase one, which you know by now, is a long way away from the end of the development road.

When Vox spoke to company representatives, they explained that the normal pathway for bringing a vaccine to market takes 10 years, and that they were already three years into the process with the Ebola vaccine. While this crisis has focused attention on Ebola drug development and helped to galvanize resources, they were not yet clear on what would happen after a successful phase one trial and how much longer it would take to scale-up manufacturing and get the vaccine approved for use in people.

There's a chance that the usual process might be condensed or phases of clinical testing skipped, since Ebola is an unusually deadly pathogen and will be treated differently by regulators. But even in dire situations, developing safe, new therapies takes time, and unfortunately, mostly ends in failure.

We're only in phase one with the Ebola vaccine. If data look promising, hopefully regulators will find ways to make sure it's not seven more years until we can prevent another Ebola epidemic.

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