Ebola Vaccine Trials Forcing Tough Choices

An anonymous reader writes: Medical researchers hope an experimental vaccine for Ebola can help protect against infection and slow the spread of the disease. Efficacy trials for the vaccine begin in a few months, and it's forcing some difficult decisions for health care officials. The first test will involve front line health care workers, who, as a group, are at the gravest risk of infection. But every trial needs a control group, and scientists are bitterly divided over whether the vaccine should be withheld from a portion of those putting their lives on the line to protect the rest of us. Development of the vaccine has been vastly accelerated already, due to the virus's spread and its mortality rate.

"The leading alternative is a design known as step-wedge, which essentially uses time to create a control group. In this design, researchers take advantage of the inescapable reality that large-scale trials can't give everyone the vaccine on the exact same date; they compare the rates of infection in people already vaccinated with those who have yet to receive the shots. Barney Graham, a virologist ... says "people are more comfortable" with the step-wedge design, because everyone in such a study would get the Ebola vaccine. But statistically speaking, this design makes it more difficult to determine the vaccine's worth, and it takes longer." NY Mag has a related story summarizing the treatments currently being used to fight Ebola.

Comments

The risk in rushing drugs

[sjbe]

One problem with rushing a treatment to market (aside from the obvious side effects and toxicity risks) is that you sometimes end up with a treatment that works but you have no idea why it works. This has happened with some drugs in the past. We've started testing them and found that they worked really well. So we stopped the clinical trials early in order to rush the drug to market quickly for perfectly appropriate humanitarian reasons. After all if you have a drug that you know works then it's pretty cruel to withhold it from someone who would benefit. The problem is that sometimes we know a drug works before we know why or how it works.

Part of clinical trials is figuring out if a treatment will work. The other part which is sometimes even more important is figuring out why a treatment works so that we can build off that information in the future. If you skip or stop clinical trials early you sometimes end up losing this critical information. If we don't know why something works it's pretty hard to make further progress in developing even better treatments.