Here's Everything We Know About The 'Secret Serum' Used To Treat An American With Ebola

Both of the Ebola-infected U.S. citizens in Liberia received a rare dose of an experimental serum to treat the virus before being transported to Emory University Hospital in Atlanta, according to a CNN report. And while some people do fight off the disease on their own, in the case of the two Americans, that experimental serum may have saved their lives.

As Dr. Kent Brantly and missionary Nancy Writebol waited in a Liberian hospital, someone from the National Institutes of Health reached out to Samaritan's Purse, one of the two North Carolina-based Christian relief groups the two were working with, and offered to have vials of an experimental drug called ZMapp sent to Liberia, according to CNN's unnamed source.

Although the Food and Drug Administration does allow experimental drugs to occasionally be distributed in life-threatening circumstances without approval under the expanded access or "compassionate use" conditions, it's not yet clear whether that approval was granted in this case or not.

A spokesperson for the FDA told Business Insider that federal law and FDA regulations prohibit them from commenting on specific products, as that information is considered confidential.

An Emergency Treatment

However it was approved, three frozen vials of ZMapp, a drug being developed by Mapp Biopharmaceutical, were flown to Liberia and arrived the morning of Thursday July 31.

The serum needed eight to 10 hours to thaw.

Brantly, who had been sick for nine days already, reportedly had asked that Writebol receive the first dose, as he was younger and thought he had a better chance of surviving. (It's unclear from the CNN story why the doses apparently were not all ready at the same time.)

But his condition worsened as the first dose thawed, and CNN reports that he told his doctors, "I am going to die."

He asked for the first dose and had it given to him through an IV. According to CNN's source, within an hour, he was able to breathe better and a rash on his body started to fade. The next day he was able to shower without help before boarding the air ambulance that flew him to Atlanta.

Writebol reportedly didn't respond as well to the first treatment she received, and had to be given the third vial of serum. Her second treatment seemed to improve her condition, according to CNN, and stabilized her enough that she's expected to fly to the U.S. on Tuesday, August 5.

Could Drugs Stop The Epidemic?

This Ebola outbreak - the worst in history - has already killed 887 people. But promising news of an experimental serum doesn't mean that a treatment is close.

Developing a cure for a virus is complicated, and developing a treatment for Ebola has proven particularly difficult.

In this case, since health officials can't comment on a specific treatment or on the patients involved for privacy reasons, we don't know the exact status of Brantly and Writebol or how that status has been affected by the serum that they reportedly received.

Before this emergency use, ZMapp had only been tested in a small number of monkeys. The company reported that all four monkeys who received the treatment within 24 hours of being infected survived. Half of the four monkeys who were treated within 48 hours survived.

Brantly and Writebol had been sick much longer than that before being treated, and treatments that work in animals - especially such a small number of animals - routinely fail to work in human trials.

Standard "treatment" for Ebola usually involves trying to keep patients hydrated and alive long enough to give the immune system a chance to battle the virus. And while that approach may sound unpromising, this outbreak has had a fatality rate of about 60% so far, not close to the 90% that's often reported.

That 60% number could still rise, but survival cannot necessarily be attributed to an experimental treatment. While Ebola is highly fatal, some people do survive without any extraordinary interventions.

A Tale Of Two Drugs: Mapp Vs. Tekmira

ZMapp is not even far enough along to have entered the clinical trial phase, but it may have been chosen in this case instead of the promising experimental drug Tekmira because an ongoing Tekmira trial was just halted by the FDA.

That doesn't mean that all research on Tekmira is over, however. The ongoing trial was halted because healthy patients showed a problematic immune response. But the FDA could still approve a new trial of the drug in sick patients, as the risk-benefit equation would be changed. A potential benefit of surviving a disease that kills 60-90% of patients could outweigh the risks of many potentially problematic side effects.

CNN also reported that on July 30, the military approved additional funding for Mapp Biopharmaceutical because of their promising results so far.

If either ZMapp or Tekmira proves to be effective; testing, approving, and then producing a drug will still take time, even if the process is fast-tracked.

At this point, the best hope for stopping this outbreak is not curing it, but containing it.

Even though the virus can only be transmitted by close contact, and thus it can be contained, health officials have been completely unable to do so in West Africa due to a combination of factors including poor healthcare infrastructure, distrust of authorities, traditional burial practices, and fear of healthcare providers.

At the present rate, World Health Organization chief Margaret Chan describes the consequences of not being able to stop the disease's spread as "catastrophic."