LONDON (Reuters) – Scientists working on the development of Ebola vaccines have found they can "scoop" antibodies from vaccinated volunteers into research and use them to make treatments for deadly viral infection.
FILE PHOTO: A Congolese health worker administers the vaccine against Ebola to a boy who had contact with an Ebola carrier in the village of Mangina in North Kivu province of the Democratic Republic of Congo, August 18, 2018. REUTERS / Olivia Acland / File Photo
In a study published in the journal Cell Reports on Tuesday, the scientists said the approach could be used for Ebola and other new deadly diseases caused by viruses.
The technique, based on people exposed to the Ebola vaccine, but not to the Ebola virus itself, suggests that protective therapies can be developed from people who do not have diseases.
"It's a small extra step that can lead to new antibody therapies from an increased number of donors and at reduced risk," said Alain Townsend, a professor at the Human Immunology Unit at Oxford University in Britain.
He noted that in addition to Ebola, many experimental vaccines for other life-threatening infections, such as H5N1 and H7N9 avian influenza and the Middle Eastern Respiratory Syndrome (MERS), are entering clinical trials and may offer similar antibody collection opportunities .
Ebola is now spreading in the Democratic Republic of Congo, where data from the World Health Organization show that at least 676 people have been killed and more than 700 others have been infected in an outbreak that began eight months ago.
The largest Ebola epidemic in history swept Sierra Leone, Liberia and Guinea in 2013-2016, killing more than 11,000 people. This outbreak led to a global effort to develop vaccines and treatments – and some, including a protective shot developed by Merck and various antibody therapies for infected patients, were implanted in the Congo outbreak.
Antibodies intended for treatment are usually collected from the blood of people who have survived the infection. But they can also be difficult to obtain and carry greater risks, such as potentially persistent viruses or other pathogens.
The Oxford team decided to try to use blood from volunteers who received an experimental vaccine against Ebola and whose immune system responded to the vaccine by producing antibodies. They successfully isolated 82 antibodies from 11 volunteers on trial at the Jenner Institute in Oxford.
They found that, despite having less time to develop, one-third of the antibodies were effective in neutralizing an Ebola strain known as Zaire – the cause of the Congo outbreak.
The scientists then concocted four of the antibodies to create a treatment, which successfully cured six Ebola guinea pigs when it was given three days after infection.