The Ebola virus is spreading rapidly and to an unexpected extent. The outbreak does not follow the patterns experienced in the past and the virus shows a new disease dynamic in regions, where it has never been recorded before. For this reason, the German National Academy of Sciences Leopoldina, acatech - the German Academy of Science and Engineering, and the Union of the German Academies of Sciences and Humanities have presented a statement on the Ebola epidemic today.
(Ebola hemorrhagic fever - EHF) is the human disease caused by ebola viruses. Symptoms start 2 days to 3 weeks after contacting the virus with a fever, throat and muscle pains, and headaches. There is then nausea, vomiting and diarrhea along with decreased functioning of the liver and kidneys. At this point some people begin to have problems with bleeding. Ebola first appeared in 1976 in 2 simultaneous outbreaks, in Nzara, Sudan, and in Yambuku, Democratic Republic of Congo. Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals - Ebola Information from the CDC.
In the statement the academies call for the following consequences to be taken:
To combat the Ebola epidemic vaccines and antivirals are urgently needed. To meet this need, the further development of experimental vaccines and medicines for clinical application needs to be accelerated. Even if the pathogen should temporarily disappear again, research must continue as a precautionary measure because another outbreak is highly probable. Such precautionary measures must also include ensuring that sufficient quantities of available vaccines and antivirals are stockpiled in case of a new outbreak. Increasing medical and social science research in this area is also vitally important for future preparedness.
On 8 August, the World Health Organization (WHO) declared the Ebola outbreak in West Africa to be an international public health emergency. In particular, the WHO advised that:
The United Nations Security Council agreed with this assessment in its declaration of 18 September 2014 which stated that the epidemic constitutes a threat to international peace and security.
The current Ebola outbreak
Since its discovery in 1976, there have been repeated outbreaks of the Ebola virus, which were generally contained to remote regions of Central Africa and never amounted to more than 500 cases.
The current outbreak of the virus is entirely different to past outbreaks. After the first cases were recorded in early 2014 in South-West Guinea, the disease has spread rapidly. Alongside Guinea, Sierra Leone and Liberia, with its million-plus capital Monrovia, have been hit especially hard. The spread of the virus has been accelerated by multiple factors including disastrous hygiene conditions, the collapse of the medical infrastructure and a lack of public awareness. Over 8000 cases were registered by 5 October 2014. About half of the people infected have died. The death toll includes many doctors and nursing staff and an end to the outbreak is not in sight. From the beginning, the local healthcare systems have been supported by international aid organizations: Doctors Without Borders and the European Mobile Laboratory Project were the first to come to the region in March 2014. From very early on, these organizations have repeatedly said that the outbreak will not be contained without a massive increase in medical and epidemiological aid.
The Ebola virus and its progression
The Ebola virus and the Marburg virus are filoviruses, research on which started with discovery of the Marburg virus in 1967. Research in this area that has been carried out in Germany has significantly contributed to understanding the nature of the Ebola virus. This research furthermore delivered important approaches to control and fight the virus, such as the procedures to identify the virus which are being applied by the European Mobile Laboratory in the current outbreak. In addition, one of the two vaccines to be tested in the clinic is based on research originally carried out in Germany.
Ebola viruses are transmitted from animals to humans. Fruit bats are presumed to be the natural reservoir of the virus. The Zaire species of Ebola virus, responsible for the current outbreak in West Africa, causes a particularly severe form of haemorrhagic fever. The disease progresses primarily with massive virus proliferation and immune dysfunction. The main symptoms are fever, diarrhea, vomiting and impaired coagulation, leading to multiple organ failure and shock. Initial examinations of the genetic material have shown that the virus is different to past strains with numerous genetic changes (mutations), but the significance of this is not known.
Experimental medicines and vaccines
There are as yet no vaccines or antiviral drugs that have been registered for human use. Interventions that are still in an experimental phase, some of which were developed over 10 years ago, have now taken on a special importance. These include antiviral drugs based on nucleic acid molecules (siRNA) and therapeutic antibodies, and vaccines based on recombinant viruses. Under pressure of current events, the vaccines and therapeutics that have shown good results in animal experiments are now being tested in initial clinical studies. The process of moving from the experimental phase to clinical application will certainly be cost-intensive and time-consuming. The thought that numerous lives could have been saved, had this process been started earlier, is depressing.
The Ebola virus epidemic on this scale presents completely new challenges, both to the countries that are directly affected and the international community. Germany, together with other industrialized countries, has an important role to play here. Some of the key consequences that need to be taken are:
Strengthen international collaboration and capacities
Expand medical and social science research
Rapidly apply existing developments for vaccines and drugs
Prof Hans-Dieter Klenk, Philipps-Universitat Marburg, Institute of Virology (head of the working group)
Prof Stephan Becker, Philipps-Universitat Marburg, Institute of Virology
Prof Bernhard Fleischer, Bernhard-Nocht-Institut for Tropical Medicine , Hamburg
Prof Detlev Ganten, Charite Universitatsmedizin Berlin
Prof Jarg Hacker, President of the German National Academy of Sciences Leopoldina
Prof Reinhard F. Huttl, President of acatech - German National Academy of Science and Engineering
Prof Thomas C. Mettenleiter, Friedrich-Loeffler-Institute, Federal Research Institut for Animal Health, Insel Riems
Prof Alfred Puhler, Bielefeld University, Center for Biotechnology - CeBiTec
Prof Gunter Stock, President of the Union of the German Academies of Sciences and Humanities
Prof Volker ter Meulen, Julius-Maximilians-Universitat Wurzburg, Insitute of Virology
The Ebola epidemic: Is there a way out
(The following is an excerpt from a recent press release by the International Union of Immunological Societies)
Not everyone who contracts the Ebola virus dies, the survival rate is around 30% suggesting that some kind of immunity to the disease is possible. Experimental treatments and vaccines against Ebola exist but have not yet been tested in large groups for safety and efficacy (phase 2 trials).
"The current Ebola outbreak, is an unprecedented disaster for humans. This virus cunningly hijacks the human immune system with devastating effects. Without blocking transmission, Ebola may become endemic," says Prof Clive Gray, author of the paper and member of the Clinical Immunology Committee of the IUIS, from the Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, South Africa. "Efforts are being made on health communication in order to prevent the spread of this virus from person to person. This is essential but not enough. Stakeholders need to work together to accelerate the roll out of vaccines and therapies," Gray stated.
Authors explain that although no licensed vaccines exist on the market, "significant progress" has been made in recent years and especially in the last few months. Among the promising vaccines being tried today, the paper mentions the Cad3 Ebola vaccine developed using chimpanzee adenovirus. This vaccine was found to protect animals with a single dose and is currently undergoing phase 1 trials (where researchers test the vaccine candidate in a small group of people to evaluate safety, determine safe dosage and identify side effects). Another promising vaccine candidate is rVSV-ΔG-ZEBOV that has proven safe and efficient in non-human primates with no major toxicities. Phase 1 trials for this vaccine started in October.
Commenting on the need for a vaccination strategy, Prof Marylyn Addo, Department of Medicine, Division of Emerging Infections and Tropical Medicine, University Medical Center, Hamburg, Germany explained: "the fact that the current outbreak of Ebola is through a single strain with low mutability, suggests that vaccine strategies could be easily achievable. Understanding how immunity works in survivors of Ebola may further contribute to strategic vaccine design and optimization. Addo concluded that: we need to speed up the development process in order to advance clinical testing and, ultimately, the deployment of effective vaccines. However, despite the urgency of the situation, the safety of the vaccines for recipients needs to be ensured and cannot be compromised."
Alongside vaccination (to prevent infection), the IUIS paper says that experimental therapies are also available to treat people who are already infected with the virus. ZMapp, for example, combines antibodies that cling to the virus and allow the immune system to clear it. The drug has been tried on animals and humans with different outcomes. Currently the drug is not available, so it cannot be tested further.
Other therapeutic approaches are siRNA (also known as TKM-Ebola) and Favipiravir (T705). "These drugs need to be tried for efficacy and safety, but currently we do not have time to conduct traditional studies," explained Prof Reinhold Schmidt, Director of the Center of Internal Medicine, Division of Immunology and Rheumatology, University of Hannover, Germany.
The IUIS paper calls for a speedy roll-out of a human vaccine to Ebola. Prof Schmidt continues, "Of course we do not overrule the need for trials to ensure safety, but IUIS is calling on authorities to speed up the process by a) performing parallel animal safety and immunogenicity studies alongside human phase 1 clinical trials with small sets of volunteers to assess safety and optimal dosage and b) rapidly designing and implementing phase 2 clinical trials." Prof Schmidt concluded: "Time is not on our side. Funding is urgently needed, as well as a more flexible and speedy process to make vaccines available to populations at greatest risk, in order to halt this devastating Ebola outbreak."