Ebola Update: CDC answers questions about ZMapp, the 'secret' experimental serum given to two American doctors

Saturday, August 9, 2014, 12:20 PM - As the Ebola epidemic in Africa continues to claim more lives, and concerns are being raised that it is now 'out of control' two doctors from the United States appear to be on the mend after receiving an experimental serum known as ZMapp. This week, the Center for Disease Control and Prevention (CDC) answered questions about this new drug.

What is ZMapp?

ZMapp is a new serum, made up of three different kinds of antibodies, that is in development specifically to combat the Ebola virus. It is still in the experimental phase and has not yet reached the point where it has been tested for safety in humans.

Is ZMapp a cure for Ebola?

No. Without having gone through human clinical trials, there's no way to be sure if the treatment is actually effective in humans. The fact that both doctors are now seeing signs of improvement after receiving the treatment is a good sign. However, it's possible that they were going to improve on their own, regardless of receiving this serum. There have already been examples during this outbreak of patients getting better on their own, and this may simply be two more cases of this kind of recovery.

Is this a vaccine against Ebola?

No. There is no vaccine for Ebola yet. ZMapp is simply a treatment for someone who has become infected by the virus. Even if it does prove effective against the virus, it is not designed to prevent someone from becoming infected.

Why did these American doctors receive ZMapp if it hasn't been through human clinical trials?

Samaritan's Purse, an evangelical Christian missionary group that one of the two doctors (Dr. Kent Brantly) works for, followed a chain of contacts from the CDC to the National Institutes of Health (NIH) to the company developing the serum, Mapp Biopharmaceutical Inc. Presumably, Samaritan's Purse and Mapp Biopharmaceutical Inc. were able to come to some kind of agreement to provide the experimental treatment to the two doctors, who are being cared for at Emery University Hospital, in Atlanta, GA.

It's worth noting that this deal apparently circumvented the required Food and Drug Administration approval, that's needed in the U.S. to administer an experimental drug, as the serum was given to the doctors while they were still in Liberia.

Will this treatment now make its way to the people in Africa?

The short answer is 'no'. The full answer is a bit more complicated. The two doses given to the doctors were apparently from a very limited supply, and the company is unable to manufacture large quantities of the serum at this time. Also, since it's too early in the serum's development to tell how effective it actually is for humans, offering it up for wide-spread use may actually do more harm than good. It's possible that it may turn out to be the cure we've been waiting for, to save those infected. However, if it turns out to be ineffective, temporary, or simply a mask for the symptoms of the infection, using it right now could actually help the epidemic to spread further. Without testing it first, it is a roll of the dice that could end in disaster.

This whole situation is drawing flak from the authorities in Africa. This action by Samaritan's Purse shows an extreme level of favoritism, given that this humanitarian organization (presumably) spent significant resources to secure this serum for two of its own, while hundreds of people in West Africa are currently suffering and dying from the infection. It has also drawn the ire of officials in Liberia, since Samaritan's Purse apparently also avoided getting the necessary approvals to administer the experimental drug in their country. Their decision may have involved the reasoning that saving these two doctors will ultimately help more people in the end, but their reputation may have been damaged in the process.

Are there other treatments or vaccines in development?

Yes. There are two other companies currently working on treatments, and one vaccine candidate is in development by a third company. However, of these three, only one of the treatments (from Biocryst Pharmaceuticals) has advanced to the point where they're ready to start Phase 1 trials. Phase 1 trials are where a drug or treatment is tested solely for its safety, its safe dosage levels and any side effects. The effectiveness of a drug or treatment doesn't start until Phase 2, when it's tested against a placebo.

The full Q & A can be found on the CDC website (click here), and more information and updates on the Ebola virus and its spread are available on both the CDC and World Health Organization (WHO) websites.

As it stands now, the situation in West Africa is growing worse. As of Wednesday, August 6, the WHO reported a total of 1,711 cases across Guinea, Liberia, Nigeria, and Sierra Leone (over 60 per cent of which have been confirmed). 932 of those infected have died. It is feared by some doctors that the infection is spreading out of control, since those numbers include over 100 new cases reported and 45 deaths over just the past weekend (August 2-4). According to BBC News, a Saudi Arabian man who was recently in West Africa has died in a suspected case of Ebola (although that has not yet been confirmed). Although there have been some scares in other countries, including the United States and the UK, the only cases currently outside Africa (and Saudi Arabia if that case is confirmed) are the two doctors in Emery University Hospital, and a priest who has now been flown home to Madrid, Spain for treatment. All other potential cases have been ruled out.

(Correction: The previous version of this article said that Samaritan's Purse and Mapp Biopharmaceutical Inc. obtained the necessary approval from the FDA. The article has been updated to reflect the fact that no such approvals were given, due to the serum being administered before the doctors arrived in the United States.)