Has the Time Come to Test Experimental Ebola Vaccines?

Written by on July 28, 2014 in Featured on App, News, Prophylactic Vaccines with 3 Comments

The Ebola Virus is Spreading Across West Africa in The Largest Outbreak To Date

The Ebola Virus is Spreading Across West Africa in The Largest Outbreak To Date

Mortality rates are currently at 60%, where normally up to 90% of affected people die. Unfortunately, there are no cures or vaccines for the disease, despite its emergence in 1976.

In March of this year, cases of Ebola were reported for the first time in Guinea, Western Africa. Notably, these outbreaks took place in Guinean districts that bordered Sierra Leone and Liberia. In the past, outbreaks have taken place in remote areas of Africa, but this outbreak has had the opportunity to cross border and spread throughout Western Africa, and it has done just that. Now fourth months since the March outbreak, 1,093 people have been infected and there have been a reported 660 deaths attributed to the deadly virus (source: CNN vital signs.)

David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine (LSHTM) who was on site in for the first Ebola outbreak in Zaire, DRC in 1976, has said that ‘this is clearly an outbreak across international borders and it has not been handled properly.’ Heymann says ‘it’s not rocket science to control these outbreaks but instead basic epidemiology: infection control, hygiene practices, contact-tracing and safe burial practices.’ Since the virus in transmitted through contact with infected bodily fluids, the virus is highly contagious and hygiene when dealing with patients is of the utmost importance.

There are no licensed drugs or vaccines for use against Ebola as its periodic and usually small-scale nature means there has not been a big enough market nor the opportunity to conduct large-scale trials in humans exposed to the disease.

The biology of the virus also makes it difficult to develop vaccines that create an adequate immune response as there are multiple strains of the virus, meaning an immune response is needed against all of them. To complicate matters, Ebola’s ability to replicate rapidly could mean the virus may rapidly evolve resistance against a vaccine.

Despite these challenges, there are vaccines that are currently being developed, with a vaccine program by the vaccine research center at the U.S. National Institute of Allergy and Infectious Diseases (NIAID) having progressed the furthest. ‘We are supporting a number of vaccines and they are all in a roughly similar position and getting ready for Phase I trials for safety,” says Dr Mike Kurilla, director of their Office of Biodefense Research Resources and Translational Research. ‘If these make it through testing what we’re likely to see in future outbreaks is healthcare workers and outbreak investigators taking the vaccine under informed consent,” Kurilla explains. “Working with those at the highest risk will enable you to see if the vaccine has an impact.’

Dr Jeremy Farrar, director of global charitable foundation the Wellcome Trust, says that ‘Any new intervention must have pre-clinical safety and efficacy data and Phase I safety data in healthy volunteers’ and that ‘ultimately there can be no Phase II (vaccine efficacy) data in Ebola other than that acquired during an epidemic.’

Peter Piot, Director of the LSHTM, warns that caution must be exercised if the safety of experimental drugs is to be assessed during an outbreak, then is must respect ethical standards, as there is a growing mistrust towards healthcare professionals amongs communities affected by the virus. Here, Piot refers to resentment towards healthcare professionals who enter these communities in fully protective suits and tell them to change their cultural practices, particularly their burial traditions (which involve cleaning the body), in order to prevent spread of the disease. As a result, healthcare officials are often threatened with weapons. Indeed, there is a fine balance that must be struck between safe disease prevention practices and understanding and respecting local traditions.

The WHO does not condone using experimental vaccines in these outbreaks, claiming this would be ‘unethical.’

It is too late in this outbreak for vaccines to have enough of a preventative impact, but Ebola will emerge again in the future. If safety can be proven, vaccines could improve help prevent future outbreaks.

Read more about it here: Ebola outbreak: Is it time to test experimental vaccines?

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About the Author

About the Author: As a 4th year student studying Biology with management at Imperial College London, I have a passion for health issues and the microscopic world of bacteria and viruses. I'll be around for a while writing about the cutting edge issues that are shaping the pharmaceutical industry and medical progress around the world. .

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  1. Anna Watson says:

    Indeed not rocket science to adopt good isolation and hygiene measures :)
    Just as Leicester did in the UK during the Smallpox outbreak resulting in the lowest mortality despite the lowest vaccination rate!

  2. Mohammad Azam Khan says:

    The under trial vaccines if safe seem promising to support in the context of, God forbid, future outbreaks. The societal situations of present day Africa and UK do not match to expect similar implementation of basic epidemiological control measures.

  3. Ed Rybicki says:

    Fairly prophetic – although it wasn’t vaccines that were first used, but a therapeutic agent. And made in plants, at that!

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