Ebola Update

Vaccines, convalescent blood plasma in fast-track trials


Keeping pace with the rapid spread of Ebola Virus Disease since its outbreak in West Africa in March this year is difficult in the context of this magazine which is published only every two months. Rather than provide figures of infections and deaths which are growing exponentially in affected countries and will be outdated by the time the magazine reaches readers – we look instead at progress being made to develop vaccines and treatments for the disease.

Nonetheless – as we go to press – Ebola cases have been recorded in Liberia, Sierra Leone, Guinea, Mali, Spain and the United States. Nigeria and Senegal, which had earlier recorded a number of Ebola cases, are now considered Ebolafree, following a period of 42 days with no new infections.


On 23 October WHO convened a meeting with high-ranking government representatives from Ebola-affected countries and development partners, civil society, regulatory agencies, vaccine manufacturers and funding agencies to discuss and agree on how to fast track testing and deployment of vaccines in sufficient numbers to impact the Ebola epidemic. Key consensus commitments

- Results from phase 1 clinical trials of most advanced vaccines are expected to be available in December 2014 and efficacy trials in affected countries also will begin in this timeframe, with protocols adapted to take into consideration safety and immunogenicity results as they become available.

- Pharmaceutical companies developing the vaccines committed to ramp up production capacity for millions of doses to be available in 2015, with several hundred thousand ready before the end of the first half of the year. Regulatory authorities in countries where the vaccines are manufactured and in Africa committed to supporting this goal by working under extremely short deadlines. Trials of vaccines have already begun in the US, UK, and Mali, and are beginning in Gabon, Germany, Kenya and Switzerland to determine safety and dose level.

“As we accelerate in a matter of weeks a process that typically takes years, we are ensuring that safety remains the top priority, with production speed and capacity a close second,” said Marie-Paule Kieny, WHO Assistant Director-General of Health Systems and Innovation.

Swissmedic, the Swiss regulatory authority for therapeutic products, has given approval for a trial with an experimental Ebola vaccine at the Lausanne University Hospital (CHUV). The vaccine is based on a genetically modified chimpanzee adenovirus (“ChAd- Ebola”; Chimpanzee-Adenovirus chAD3- ZEBOV). The trial will test the safety of the vaccine and its capacity to induce an immune response.

Results from the CHUV trial will – together with the results of other centres involved – provide the basis for planning subsequent trials involving several thousand participants, and for choosing vaccine dose-level for efficacy trials.

Developed by the US National Institute of Allergy and Infectious Diseases (NIAID) and pharmaceutical company GlaxoSmithKline, the vaccine consists of a virus that is rendered harmless and used as genetic carrier for one Ebola protein. The application, submitted at the end of September 2014, was handled as a priority, given the dimensions of the Ebola epidemic in West Africa.

The trial is one of two in Switzerland coordinated by WHO. A second vaccine, rVSV-ZEBOV, is to be tested at the Geneva University Hospitals, concurrent to the Lausanne trial. Results are expected in December this year. “These are dosing and safety trials being held in advance of to Phase II and III trials currently scheduled for late 2014-early 2015,” said Kieny.

Blood plasma

Another potential treatment that is being given considerable attention is the assessment of whether the blood or plasma of Ebola survivors can be used to treat Ebola patients in West Africa.

Blood and plasma from recovered Ebola patients has been used in a limited number of patients previously. For example, during the 1995 Ebola outbreak in Kikwit, in the Democratic Republic of the Congo (DRC), seven out of eight patients receiving convalescent whole blood survived.

However, whether this was due to the transfusions or to other factors is unclear. To study this, an international team of researchers has received £2million from the European Union (EU) to evaluate the safety and efficacy of blood and plasma donated by people who have recovered from Ebola.

The use of convalescent blood and plasma will be trialled in Guinea in November by the research consortium led by Dr Calum Semple from the University of Liverpool’s Institute of Child Health based at Alder Hey Children’s Hospital and Dr Johan van Griensven of the Prince Leopold Institute of Tropical Medicine Antwerp. Commenting on the research, Dr Semple said: “Convalescent plasma therapy is a medical intervention which has been used for a long time to treat other diseases safely.

We want to find out whether the Ebola plasma will work, is safe and can be used to reduce the number of deaths in the present outbreak.”

Ebola Tracking www.ebolatracking.org

 Date of upload: 14th Nov 2014


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