Gates Foundation pledges $5.7 million for Ebola research

The Bill & Melinda Gates Foundation has pledged $5.7 million to test treatments for Ebola in Guinea and other countries in West Africa.

The research will test the usefulness of blood donations from Ebola survivors — known as convalescent plasma -- as well as an experimental antiviral drug called brincidofovir. Doctors have used blood donations from Ebola survivors for four decades, but no one really knows if the procedures work.

That's because they've never been studied in a scientific way, said Amesh Adalja, senior associate at the Center for Health Security at the University of Pittsburgh Medical Center.

To try to resolve these questions, Doctors Without Borders also will begin clinical trials of experimental Ebola therapies in West Africa in December.

"We are committed to working with Ebola-affected countries to rapidly identify and scale up potential lifesaving treatments for Ebola," said Papa Salif Sow, a senior program officer and infectious diseases expert with the Gates Foundation's global health program. The foundation is focusing on "treatments, diagnostics and vaccines that we believe could be quickly produced and delivered to those who need them if they demonstrate efficacy in stopping the disease."

Blood will be collected by mobile donation units, the foundation says.

Ebola survivors who are potential donors will be tested to ensure that they are cured of Ebola and are not infected with other blood-borne diseases, such as HIV or hepatitis. Blood also will be treated to kill dangerous germs.

In the past, doctors mainly transfused "whole blood" from a survivor into a patient. In more developed countries, doctors can separate blood so that they transfer only the plasma, or liquid part, which contains antibodies. Antibodies are proteins made by the immune system that shut down viruses such as Ebola. Scientists hope that these antibodies will give patients' immune systems a head start in fighting the virus.

Because the process transfers only part of the blood, donors don't become anemic or weakened. That means they can donate every two weeks, according to the Gates Foundation. In comparison, people who donate whole blood must wait three months before giving blood again.

Beyond new treatments and vaccines, West Africa urgently needs better tests to diagnose Ebola, according to the World Health Organization.

Although these tests are regarded as highly accurate, they often can't detect the Ebola virus until a patient has had symptoms for two to three days, said infectious disease expert Peter Hotez. That's because the level of virus in the blood is very low in the early stages of infection.

The limitations of the current DNA tests for Ebola were revealed by the case of surgeon Martin Salia of Sierra Leone, who tested negative for the virus twice before being diagnosed. By the time he was airlifted from Sierra Leone to the Nebraska Medical Center in Omaha, he was in kidney failure and unreponsive. He died Monday.

According to the WHO, current Ebola tests -- known as RT-PCR tests -- cost about $100, require a full tube of blood and take two to six hours to perform. Delays in getting test results from labs can be fatal for patients. In West Africa, people suspected of having Ebola are kept in transit centers, where uninfected patients may pick up the virus from infected patients in the next bed.

The WHO is leading an effort to encourage researchers and companies to develop faster, easier Ebola tests, such as one that could be done with a finger prick's worth of blood. An ideal test could be performed at a patient's bedside and be as quick and easy as a pregnancy test, said Hotez, director of the National School of Tropical Medicine in Houston.

Several Americans infected with Ebola have received blood donations.

American Ebola patient Kent Brantly, a physician, received a blood donation from a teenage survivor before he left Liberia for treatment at Atlanta's Emory University Hospital. He later donated blood to several other Ebola patients: journalist Ashoka Mukpo, physician Richard Sacra and nurses Nina Pham and Amber Vinson. Missionary Nancy Writebol, also treated at Emory, donated blood to Vinson and Spencer.

Salia received a blood donation from an anonymous donor, along with the experimental drug ZMapp, but died less than 36 hours later.

Brincidofovir, made by Chimerix of North Carolina, was given to Mukpo, Liberian national Thomas Eric Duncan and physician Craig Spencer. Mukpo and Spencer survived. Duncan received the drug just a couple of days before he died.

Hotez said doctors should expand the use of plasma donations to fight Ebola.

"The problem is whether there is sufficient infrastructure in the affected areas of West Africa to ensure that survivors can be registered and their blood banked appropriately and then screened for adventitious agents to avoid blood-borne transmissible agents such as HIV, hepatitis C and hepatitis B," Hotez said. "So any technology that facilitates this, especially in a resource-poor setting, is welcome."

Hotez said researchers also should look into isolating just the antibodies from donors. These preparations, called immune globulins, can be given to anyone, regardless of blood type.

At least15,145 people have been infected with Ebola in Sierra Leone, Guinea and Liberia, and 5,420 have died, according to the World Health Organization. About 90% of all Ebola cases ever reported have occured during this outbreak, said Jennifer Kates, vice president and director of global health and HIV policy at the Kaiser Family Foundation.

Among health care workers, 584 have been infected and 329 have died.

The outbreak has caused West African health systems to collapse and has devastated their economies. The three hardest hit countries — Guinea, Liberia and Sierra Leone — are among the poorest in the world. A report released today from the World Bank finds that nearly half of Liberia's workforce is unemployed.