"Over the past decade, research efforts have been invested into developing drugs and vaccines for Ebola virus disease. Some of these have shown promising results in the laboratory, but they have not yet been evaluated for safety and efficacy in human beings. The large number of people affected by the 2014 west Africa outbreak, and the high case-fatality rate, have prompted calls to use investigational medical interventions to try to save the lives of patients and to curb the epidemic.
"Therefore, on 11 August 2014, WHO convened a consultation to consider and assess the ethical implications for clinical decision-making of the potential use of unregistered interventions. In the particular circumstances of this outbreak, and provided certain conditions are met, the panel reached consensus that it is ethical to offer unproven interventions with as yet unknown efficacy and adverse effects, as potential treatment or prevention.
"Ethical criteria must guide the provision of such interventions. These include transparency about all aspects of care, informed consent, freedom of choice, confidentiality, respect for the person, preservation of dignity and involvement of the community. In order to understand the safety and efficacy of these interventions, the group advised that, if and when they are used to treat patients, there is a moral obligation to collect and share all data generated, including from treatments provided for 'compassionate use' (access to an unapproved drug outside of a clinical trial).
"The group explored how the use of these interventions can be evaluated scientifically to ensure timely and accurate information about the safety and efficacy of these investigational interventions. There was unanimous agreement that there is a moral duty to also evaluate these interventions (for treatment or prevention) in the best possible clinical trials under the circumstances in order to definitively prove their safety and efficacy or provide evidence to stop their utilization. Ongoing evaluation should guide future interventions."
What Drugs Exist Currently ?
There a handful of drugs that have been shown to work well in animals.
One is Zmapp – the drug requested by the Liberian government. This contains a cocktail of antibodies that attack proteins on the surface of the virus.
Only one drug has moved onto early safety testing in humans. Known as TKM-Ebola this interrupts the genetic code of the virus and prevents it from making disease causing proteins.
The drug was trialled in healthy volunteers at the beginning of 2014 but the American medicines regulator asked for further safety information. The manufacturer says human studies may soon resume.
Another option would be to use serum from individuals who have survived the virus – this is a part of the blood that may contain particles able to neutralise the virus.
Vaccines to protect against acquiring the disease have also been shown to work in primates. American authorities are considering fast-tracking their development and say they could be in use in 2016. Trials are likely to start soon according to the WHO.
But experts warn ultimately the only way to be sure a drug or vaccine is effective is to see if it works in countries affected by Ebola.