Trending science: The quest for effective Ebola drugs and vaccines
The number of suspected, probable and confirmed cases of Ebola in Liberia, Guinea and Sierra Leone is now over 23 000 and the number of deaths over 9 200. As of yet, there are no proven treatments or vaccines. While new Ebola cases have declined from about 800 a week at the height of the outbreak to about 100 a week now there is no room for complacency. The quest to find a drug or vaccine to treat the virus remains a huge focus of the research community and unprecedented progress has been made. As the BBC reports, trials, which would normally take years and decades, are being fast-tracked on a timescale of weeks and months. Just last week, a team of French researchers testing a new Ebola drug called Favipiravir revealed that it could improve survival in patients in the early stages of the disease. Speaking at the Conference on Retroviruses and Opportunistic Infections (CROI), principal investigator Denis Malvy from the University of Bordeaux, noted however that trials are ongoing so caution should be exercised when interpreting findings. He dubbed the trial a ‘proof of concept’ that will hopefully inform future trials. The research is being led by the French National Institute of Health and Medical Research (Inserm). Science magazine reports that the first trial for Favipiravir ran from mid-December to mid-January. During this time, a total of 69 adults and adolescents received the drug for up to 10 days. Their outcomes were compared with patients receiving standard care at the same clinics for the three months prior to the trial. Sadly, almost half of the participants in the trial died, which is similar to the mortality rate in the control group. However when the researchers did a subset analysis of patients who entered the clinic with lower levels of Ebola virus in their blood, they found an increase in survival. Of the patients who were in early stages of the disease, only 15 % died compared with a 30 % mortality in the historical control group. However, Science reports that Malvy stressed at the conference that the improved mortality in the group may have not been related to Favipiravir. The drug Zmapp has also attracted attention during the outbreak and a clinical trial on it began in Liberia just last week. Led by the National Institute of Allergy and Infectious Diseases in the US in partnership with the Liberian government, the trial will enrol Ebola patients at Liberian treatment units, as well as infected aid workers returning to the United States or anyone who acquires an infection there through secondary transmission, according to Medical Xpress. Zmapp is a combination of monoclonal antibodies that bind to surface ‘spikes’ on the Ebola virus and, ideally, can inactivate the pathogen. The antibodies are grown in tobacco plants, which has made it difficult to produce the drug quickly. A number of vaccines are also in development. According to the BBC, three potential immunisations are ‘frontrunners’. One is produced by GlaxoSmithKline (GSK) and the National Institutes of Health in the US, another is being developed by the Public Health Agency of Canada and Merck. Meanwhile, a third is produced by Johnson and Johnson together with the company Bavarian Nordic. Trials for the Johnson and Johnson vaccine began in January 2015 while a trial involving 30 000 people is due to begin in Liberia to test the GSK and Merck vaccines side by side. Cases of Ebola may be in decline but West Africa still finds itself in the midst of the largest and most complex Ebola epidemic on record. The race to reduce the number of new cases from 100 a week to zero, and to ensure those who are infected can recover to full health, continues.
Countries
Canada, France, Guinea, Liberia, Sierra Leone, United States
