New approach to fight the Ebola virus and other deadly infections

Medical Research Council scientists have isolated therapeutic antibodies from healthy volunteers exposed to the Ebola vaccine, but not the Ebola virus itself, suggesting that protective therapies could be developed in people who are free of the disease.

Researchers from the MRC Human Immunology Unit at the University of Oxford said their findings could apply to other infectious diseases, from MERS to SARS. , via the avian influenza virus, thus paving the way for a rapid and cost-effective approach to the development of new antibody therapies. Their study was published in the journal Cell reports.

The Ebola outbreak, which is currently raging in the Democratic Republic of Congo, resurfaced in West Africa in March 2014 and has quickly become the largest since its discovery in 1976. A global effort aimed at developing treatments has allowed a handful of promising candidates, including therapies to help treat people already infected.

MRC scientists have examined whether blood samples taken from volunteers in vaccine trials could produce protective antibodies against Ebola. These samples are readily available in vaccine trial studies, although they have not yet been considered as they may not have the same potential as antibodies taken from the blood of survivors.

Conventionally, antibodies intended for therapy are collected from individuals who have survived the infection because the antibodies present in their blood are considered more potent by prolonged exposure. However, survivors' blood samples may be difficult to obtain and may carry risks, such as persistent viruses or other pathogens, that are linked to them.

The researchers isolated 82 antibodies from 11 healthy volunteers participating in an Ebola vaccine trial at the Jenner Institute in Oxford. Despite a reduced maturation time, the team found that one-third of all isolated antibodies were effective in neutralizing the Ebola species of Zaire, which is the basis of the vaccine. The scientists generated a "badtail" of four antibodies, resulting in a therapy that successfully cured six guinea pigs when administered on the third day of infection.

Lead author Professor Alain Townsend of the MRC Human Immunology Unit at Oxford University said, "We miss a valuable opportunity to discover the antibodies of healthy volunteers in vaccine trials. Currently, there are many experimental vaccines against which both H5N1 and H7N9 viruses infected with SARS and MERS are starting clinical trials, and we strongly recommend that these include antibody isolation. a small extra step that could lead to new antibody-based treatments from an increased number of donors.

Martin Broadstock, head of the Immunology Program at CRM, said: "This new way of using existing vaccine trials could allow for a rapid response to serious infections worldwide, requiring only a single dose of vaccine. small extra step in the design of the test, rather than relying on the survivors of deadly infectious diseases. "

The researchers sent their badtail to scientists at the Public Health Agency of Canada, where it will be tested on two other Ebola species (Bundibugyo and Sudan) that cause epidemics in humans. Depending on the results, antibodies may be available for clinical trials in humans. The researchers said that they would also make their antibodies available to other developers to determine if a combination therapy could be more effective.