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countries and will be outdated by the time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
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
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
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.
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
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
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
of upload: 14th Nov 2014