Ebola: What hope for a cure?

There is no cure for Ebola, which has killed nearly 2,000 people in west Africa, but several drugs are under development

More than 1,900 people have been killed by Ebola since the outbreak began last December [EPA]

With health experts saying about 60 percent of patients die from Ebola, efforts to develop a cure for the disease are being fast-tracked.

In a bid to stem the epidemic in west Africa, the World Health Organisation has condoned the use of experimental drugs, and experts in Geneva have been discussing which treatments are in the pipeline and how quickly they could be made available to the public. 

Here is a list of the drugs currently in development.

TREATMENT DRUGS

ZMAPP is made from three antibodies which inhibit the Ebola virus’ reproduction. Its development – which began more than 10 years ago – was partially funded by the US department of defence. The drug is extracted from infected tobacco plants, then purified. These plants need to be especially grown and harvested, making mass production of the drug a slow and difficult process. ZMapp has been found to be effective in monkeys, but has never been properly tested in humans. Several human subjects treated with the drug have recovered from Ebola, but scientists do not know if it cured them. The US government is putting up $42.3m to help accelerate testing.

TKM-EBOLA is a drug which interferes with the Ebola virus’ genes, effectively killing infected cells. It is being developed by Canadian company Tekmira Pharmaceuticals under a contract with the US department of defence worth $140m. It appears to be effective in monkeys. Human trials were put on hold in July because the drug caused a flu-like response at higher doses. Though unproven, TKM-Ebola has been cleared for use on compassionate grounds during the current outbreak.

GENERAL ANTIVIRALS

AVIGAN, also known as Favipiravir, has been developed by Japan’s Fujifilm corporation. It is currently only approved as a treatment for influenza, but tests on mice suggest it could help reduce levels of the virus in those affected. The company has offered to provide enough for 20,000 people and says it can produce more.

BCX-4430 is a broad-spectrum antiviral, developed by US-based BioCryst Pharmaceuticals. It is designed to interfere with the replication of viruses. The drug is not specifically designed to target Ebola but the US government is spent $2.4m to see if it is effective in primates.

VACCINES

VRC207 has been developed by drug giant GlaxoSmithKline (GSK). The vaccine is based on a chimpanzee cold virus which delivers a protein from the Ebola virus into the body. This prompts an immune response, without infecting the individual with Ebola. It is being tested on humans in the US by the National Institutes of Health. Testing is also planned for the UK. GSK says it will donate up to 10,000 doses of the vaccine to protect those at highest risk if testing proves its safety.

J&J COMBINATION vaccine will be tested on humans early next year. Developed by Johnson & Johnson, the vaccine combines two ingredients, one which primes and the other which boosts the body’s immune response. It has proved effective in monkeys and the company says if found to be effective in humans it can be quickly manufactured, as each component can be separately produced.

VSV-EBOV was developed by scientists at Canada’s National Microbiology Lab. It is not clear exactly how or even if VSV-EBOV protects humans from catching Ebola, but tests on animal show it is effective, even if taken after exposure to the virus. Human trials are expected to begin in October and partner company NewLink Genetics says it could produce as many as 10,000 more doses by the end of this year. In August, Canada offered to send between 800 and 1,000 doses of the vaccine to be used on compassionate grounds in West Africa, but these doses have not yet been sent.

Source: Al Jazeera