Two Ebola treatments being used to tackle the ongoing outbreak in the eastern Democratic Republic of the Congo have been proven to block the virus from replicating itself in a laboratory setting, according to new research this week.
The Centers for Disease Control and Prevention said it found that the treatments, the antiviral drug remdesivir and single-cell antibodies from ZMapp (an “antibody cocktail”), both block the growth of the viral strain causing the Ebola outbreak in cultured human cells.
The current Ebola outbreak, the second worst in history, began last summer and has already caused some 1,600 deaths, officials say. As of June, there were also three travel-associated Ebola deaths confirmed in Uganda, raising fears the epidemic has spread.
CDC microbiologist Laura McMullan said the 2014 Ebola outbreak in West Africa spurred scientists to develop many new therapies and detection tests. But she noted the current Ituri Ebola virus in the DRC is different from the Makona Ebola virus that hit West Africa due to alterations in the viral genome.
“We wanted to make sure that these therapies and tests that were developed using the 2014 Ebola viral strain would work and detect the current Ebola outbreak virus strain,” she told The Washington Times.
The current Ebola virus outbreak in Ituri and North Kivu provinces of the DRC follows the 2014 outbreak in West Africa, which saw 28,610 cases in Guinea, Liberia and Sierra Leone alone, as reported by the CDC.
This current outbreak is the 10th Ebola outbreak in the DRC since it first emerged in the 1970s.
William Schaffner, an infectious disease specialist and medical director of the National Foundation for Infectious Diseases, said response teams usually go into affected areas and recover the agent of the disease. However, it was not possible to do that in this case due to the political turmoil and violence in the DRC, he said.
Instead, Ms. McMullan and the other study’s researchers created an “authentic Ebola virus” from the ongoing outbreak using a reverse genetics system and virus sequences provided by organizations in the DRC.
Many investigational therapies are being tested in the current outbreak, although there is a lack of evidence of their effectiveness in combating the circulating virus, the study notes. With this manufactured virus, the research team tested experimental therapies being used in clinical trials, including remdesivir and ZMapp single-cell antibodies.
“Especially in these large outbreaks that continue for a long time, there can be changes that could occur in the virus,” Ms. McMullan said. “So we need to be vigilant and monitor those changes and just make sure that our capabilities of detecting the virus and our investigational therapeutics will indeed continue to be as effective as we hope to control the current outbreak as it continues.”
The research team concluded that remdesivir and the antibodies from ZMapp were as effective in fighting against the current outbreak as they were in the 2014 outbreak. However, researchers still need to test the treatments’ effectiveness outside of a lab and in the additional clinical human trials.
Dr. Schaffner said if both treatments worked in a laboratory, there is “pretty good assurance” they will work for patients if treatments can reach them. He added research by Ms. McMullan and her team will help public health responders curtail the virus and end the outbreak sooner.
Ebola most commonly affects people and nonhuman primates such as monkeys and chimpanzees. The virus spreads to people through direct contact with bodily fluids of an infected person or from someone who has died from the disease.
Although the majority of cases and outbreaks have occurred in Africa, there have been rare instances of the virus in the U.S., including 11 cases in 2014.