Two experimental Ebola drugs have been found to be effective in treating the strain of the deadly virus responsible for the deaths of more than 1,600 people in the Democratic Republic of Congo, according to new research published Tuesday.
Laura McMullan, a microbiologist at the US Centers for Disease Control and Prevention who lead the research, said the two treatments were developed based on strains from previous outbreaks and this study was the first to test them on the current one, which researchers are calling the Ituri strain.
“It’s vitally important to make sure existing treatments work against the virus that’s making people sick now,” she said.
An antiviral drug called remdesivir and another antibody treatment called ZMapp both inhibited the growth of the virus strain in human cells in laboratory studies, according to the paper published in the medical journal Lancet Infectious Diseases.
“They’re currently being tested in a clinical trial but we needed to verify and make sure that they were going to be as effective,” she told CNN.
“Information that we knew about how well they worked was based on a different Ebola virus variant so we needed to make sure that, indeed, these compounds were going to bind and block the virus and measure that, and see if it worked as well in order for the clinical trials to proceed,” she said.
According to the latest figures from the World Health Organization, the Ebola outbreak in Congo has killed 1,630 people, with 2,418 total cases of the deadly disease. It’s the second biggest outbreak of the disease in history; the largest recorded was in West Africa from that killed more 11,000 people starting in 2014.
ZMapp and remdesivir are among four promising experimental treatments that have been used in the Congo under what’s called a compassionate use framework, with doctors deciding the best treatment for each patient based, in part, on the complexity of administering and monitoring the drug, according to WHO.
In 2014, ZMapp became known when it was used to treat two American missionary workers, Dr. Kent Brantly and Nancy Writebol, who contracted Ebola in Liberia. Prior to that, the experimental drug had been tested only in monkeys.
However, a 2016 study that looked at 72 people who had had Ebola found that Zmapp might not have been a key factor in their survival. It found that although it was beneficial overall, ZMapp “did not meet the prespecified statistical threshold for efficacy.”
“This work has benefits beyond the current study,” said Inger Damon, chief strategy officer for the CDC’s 2018 Ebola response and director of CDC’s Division of High-Consequence Pathogens and Pathology. “Having access to this virus will allow us to explore whether other compounds or potential therapies affect the virus in the lab.”
Health authorities have also made successful use of an experimental vaccine that has been found to be 97% effective in the Congo Ebola outbreak.
Because the treatments are experimental, meaning they are still being studied, they are administered with strict protocols and require informed consent.
Despite the new drugs to fight the disease, Ebola is spreading to new parts of eastern Congo’s North Kivu and Ituri provinces and re-infecting areas thought rid of the virus.
Last month, it also made the long-feared jump across the border to neighboring Uganda, though those isolated cases appear to have been contained.
Deep mistrust of authorities, attacks on health care workers and simmering conflict in the region has meant that the outbreak has continued unabated 11 months after the first cases were confirmed.
In its latest update on July 4, WHO said that over the past four weeks a “general deterioration of the security situation and the persistence of pockets of community mistrust exacerbated by political tensions and insecurity” had led to delays and temporary suspensions in investigating suspected cases.