Three vials containing an experimental drug stored at subzero
temperatures were flown into Liberia last week in a last-ditch effort to
save two American missionary workers who had contracted Ebola,
according to a source familiar with details of the treatment.
The drug appears to have
worked, sources say. Dr. Kent Brantly's and Nancy Writebol's conditions
significantly improved after receiving the medication, sources say.
Brantly was able to walk into Emory University Hospital in Atlanta after
being evacuated to the United States last week, and Writebol is
expected to arrive in Atlanta on Tuesday.
On July 22, Brantly woke up feeling feverish. Fearing the worst, Brantly immediately isolated himself. Writebol's
symptoms started three days later. A rapid field blood test confirmed
the infection in both of them after they had become ill with fever,
vomiting and diarrhea.
It's believed both
Brantly and Writebol, who worked with the aid organization Samaritan's
Purse, contracted Ebola from another health care worker at their
hospital in Liberia, although the official Centers for Disease Control
and Prevention case investigation has yet to be released.
A representative from the
National Institutes of Health contacted Samaritan's Purse in Liberia
and offered the experimental treatment, known as ZMapp, for the two
patients, according to the source.
The drug was developed by
the biotech firm Mapp Biopharmaceutical Inc., which is based in San
Diego. The patients were told that this treatment had never been tried
before in a human being but had shown promise in small experiments with
monkeys.
According to company documents, four monkeys infected with Ebola survived
after being given the therapy within 24 hours after infection. Two of
four other monkeys that started therapy within 48 hours after infection
also survived. One monkey that was not treated died within five days of
exposure to the virus.
Brantly and Writebol were
aware of the risk of taking a new, little understood treatment and gave
informed consent, according to two sources familiar with the care of
the missionary workers. In the monkeys, the experimental serum had been
given within 48 hours of infection. Brantly didn't receive it until he'd
been sick for nine days.
The medicine is a
three-mouse monoclonal antibody, meaning that mice were exposed to
fragments of the Ebola virus and then the antibodies generated within
the mice's blood were harvested to create the medicine. It works by
preventing the virus from entering and infecting new cells.
The Ebola virus causes
viral hemorrhagic fever, which refers to a group of viruses that affect
multiple organ systems in the body and are often accompanied by
bleeding.
Early symptoms include
sudden onset of fever, weakness, muscle pain, headaches and a sore
throat. They later progress to vomiting, diarrhea, impaired kidney and
liver function -- and sometimes internal and external bleeding.
The ZMapp vials reached
the hospital in Liberia where Brantly and Writebol were being treated
Thursday morning. Doctors were instructed to allow the serum to thaw
naturally without any additional heat. It was expected that it would be
eight to 10 hours before the medicine could be given, according to a
source familiar with the process.
Brantly asked that
Writebol be given the first dose because he was younger and he thought
he had a better chance of fighting it, and she agreed. However, as the
first vial was still thawing, Brantly's condition took a sudden turn for
the worse.
Brantly began to
deteriorate and developed labored breathing. He told his doctors he
thought he was dying, according to a source with firsthand knowledge of
the situation.
Knowing his dose was
still frozen, Brantly asked if he could have Writebol's now-thawed
medication. It was brought to his room and administered through an IV.
Within an hour of receiving the medication, Brantly's condition
dramatically improved. He began breathing easier; the rash over his
trunk faded away. One of his doctors described the events as
"miraculous."
By the next morning,
Brantly was able to take a shower on his own before getting on a
specially designed Gulfstream air ambulance jet to be evacuated to the
United States.
Writebol also received a
vial of the medication. Her response was not as remarkable, according
to sources familiar with the treatment. However, doctors on Sunday
administered Writebol a second dose of the medication, which resulted in
significant improvement.
She was stable enough to be evacuated back to the United States and is expected to arrive before noon Tuesday.
The process by which the
medication was made available to Brantly and Writebol is highly
unusual. ZMapp has not been approved for human use, and has not even
gone through the clinical trial process, which is standard to prove the
safety and efficacy of a medication. It may have been given under the
U.S. Food and Drug Administration's "compassionate use" regulation, which allows access to investigational drugs outside clinical trials.
Getting approval for
compassionate use is often long and laborious, but in the case of
Brantly and Writebol, they received the medication within seven to 10
days of their exposure to the Ebola virus.
On July 30, the Defense Threat Reduction Agency, an arm of the military responsible for any chemical, biological, radiological, nuclear and high-yield explosive threats, allotted additional funding to MAPP Biopharmaceutical due to "promising results."
American Ebola patient 'seems to be improving'
-CNN
