Guinea pigs cured of Ebola virus with antibodies give rise to hope of treatment in humans

The 2014 Ebola outbreak in West Africa has caused more than 11,000 deaths. At the time, scientists were working on several vaccines and experimental treatments, but none was allowed to be used in humans.

Antibodies, which are special defense proteins made by our body in response to infection or vaccination, are one of the treatments studied. Once the best antibodies to fight a disease have been identified, they can be made in bulk and used as a treatment.

Our latest research, published in Cell reports, shows that antibodies isolated from volunteers who had been given an experimental Ebola vaccine were effective in overcoming the virus in six guinea pigs.

A total of 82 antibodies were derived from the blood cells of 11 vaccinated individuals. These were combined into three distinct groups, each group containing three or four antibodies with different properties. A combination of antibodies successfully cured the six animals infected with the Ebola virus during its administration three days after the start of the infection.

Perfect combination of antibodies

Vaccines can have side effects. Thus, antibodies are a safer form of treatment for people with immune system disorders, the elderly and pregnant women. Antibodies can be isolated from human blood by selecting individual B cells – the specialized immune cells that secrete antibodies. The genetic code for the production of an antibody is found inside B cells, extracted using advanced molecular techniques. Once this code is known, huge amounts of antibodies can be made in the laboratory.

Antibodies attach to viruses and prevent them from entering the cells. Each antibody has different properties, such as how and where it binds to the virus and whether it can prevent the virus from infecting cells. These properties were examined for the 82 antibodies.

The antibodies isolated in this study from vaccinated donors had the same characteristics as antibodies isolated from immunized animals and from people who survived Ebola. These anti-Ebola antibodies are already well studied and available for clinical trials in humans.

The development of antibody therapies for vaccinated healthy persons has the advantage that it solves the difficult problem of treating unscanned blood samples from survivors living in remote areas where donors may potentially harbor the Ebola virus. or other infectious viruses such as hepatitis B or HIV.

The antibody mix of this study is also under study for protection against the other two species of Ebola virus – Sudan and Bundibugyo. These have caused major epidemics in the past.

Even if the combination of antibodies fails to treat these viruses, all is not lost. The antibodies in this study, combined with antibodies from other research groups reacting against all species, could provide better treatment. Antibodies are also useful tools for studying Ebola virus and human immune responses to it. By following how the antibodies attack the cells, it is possible to identify the vulnerable parts of the virus.

This study shows that a human vaccine trial is a golden opportunity to isolate antibodies that can be used effectively as a treatment. This can be important for fighting emerging infections such as bird flu, MERS, SARS and Chikungunya, for which we have no established drugs or therapeutic antibodies.

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