Some antibodies from 1995 have proven useful in the current fight against the Ebola virus.
Researchers say they have harvested two antibodies from the survivor of a 1995 Ebola outbreak that appear to be effective against the deadly disease.
They said the treatment protects against the disease whether it’s administered immediately after infection or well after symptoms appear.
Their findings were published today in the journal Science.
Dr. Lee Norman, chief medical officer at the University of Kansas Hospital, told Healthline he was excited by the study.
“It’s a very positive development,” said Norman, who has been studying Ebola since 1976. “There is every reason for optimism.”
Old Antibodies Effective
The researchers were led by Davide Corti, a senior scientist at the Institute for Research in Biomedicine.
They studied the monoclonal antibodies taken in 2006 from an Ebola survivor 11 years after he was infected.
The researchers said the antibodies showed potent neutralizing activity against the virus. That indicated the survivor’s immune system had maintained its memory of the virus for more than a decade.
Corti’s team focused on two of the most potent antibodies, mAb100 and mAb114. They used them to treat macaques who’d been infected with Ebola.
The primates were treated twice every 24 hours, beginning one day after infection with Ebola. After five days, the macaques showed no signs of symptoms.
The researchers said the experiment showed the antibodies could be effective even if administered in the latter stages of Ebola infection.
Reasons for Optimism
Norman said the antibodies show great promise for patients already infected with Ebola.
“For post-exposure, it could be a Godsend,” he said.
The Kansas chief medical officer said there are number of positive developments from the experiment.
One is that the antibodies appear to be long lasting.
Another is since the antibodies were effective in primates as opposed to rodents, there is a good chance they’ll be useful in people, too.
“Since it works in primate models, I expect it to work in humans,” Norman said.
The antibodies are also naturally occurring, so there’s a good chance they’ll be safe.
Finally, the experiments help scientists learn more about the structure and mechanisms of the Ebola virus.
Treatment Has Limitations
Norman did say there are limitations to the usefulness of the antibody-based treatment.
For starters, it’s not a vaccine, so it might not provide lifelong immunity, especially if it’s given to someone who has never been infected with Ebola.
In addition, since the antibodies are harvested from humans, it may not be practical to distribute in mass amounts.
“There is the concern about if you can get sufficient quantities,” Norman said.
There’s also the question on when to use it. Do you give to anybody who has been exposed to Ebola? Or do you wait for symptoms to show up?
Norman said the antibodies would probably be used much like rabies treatment and given to people once they’ve been exposed.
“The antibodies are a good stopgap measure until we have a vaccine or medication,” he said.
Concerns About the Brain
The antibody treatment announcement comes one day after other scientists revealed that most of 82 survivors from last year’s Ebola outbreak in Africa have brain symptoms more than six months after infection.
The survivors were all from Liberia and had an average age of 35.
The researchers said almost all of them had some neurological abnormalities, including headaches, memory loss, and depression.
Furthur studies are being done on the survivors.
"While an end to the outbreak has been declared, these survivors are still struggling with long-term problems," said study author Dr. Lauren Bowen of the National Institute of Neurological Disorders and Stroke (NINDS) in Maryland and a member of the American Academy of Neurology (AAN) in a statement. "It is important for us to know how this virus may continue to affect the brain long term.”
Their findings will be presented in April at the AAN meeting in Canada.
The research was released just one day after it was announced that British nurse Pauline Cafferkey had been admitted to a London hospital for treatment of post-Ebola symptoms.
It’s the third time Cafferkey has been treated for Ebola since being infected in 2014 in Sierra Leone. She was reported in stable condition on Friday.
Norman said long-term health problems from Ebola infection aren’t a surprise for him, but they are a concern.
He said it’s known that Ebola is a complex disease that can attack different parts of the body. He added it would be “disturbing” to discover the ailment is immunological or chronic.
That’s why it’s important that research continues, he added.
“I don’t think we’ve scratched the surface on what we know about Ebola,” Norman said.