Even though we know more about the virus – and recently
developed newfangled cures – when we first discovered it back in the 1970s, but
will we be able to control the spread of the Ebola virus?
By: Ringo Bones
The Ebola virus’ co-discoverer David Heymann was quite
optimistic in a recent press interview that it is not yet too late to stop the
spread of Ebola. The medical community even managed to just recently develop a
novel cure against the virus that saved the lives of two American doctors that
volunteered in the area where the recent Ebola outbreak – as in the 2014 Ebola
outbreak - flared up. And even though we have a lot more to be optimistic about
compared to 19 years ago when the last major epidemic of the virus occurred,
can the Ebola epidemic ever be stopped?
Part of the problem of developing an effective and / or
practical cure against Ebola is due to the fact that it is a relatively
recently discovered virus. Filoviruses – a family of viruses where Ebola belongs
– were utterly unknown before 1967, where the first member of the family,
Marburg virus, arrived in Germany in a shipment of African green monkeys. While
the Marburg virus appears less dangerous to humans than the worst forms of
Ebola, it shares a number of peculiarities with its more lethal cousin,
including a puzzling mode of interaction with the human immune system. For
reasons not yet clear, animals – and this include laboratory animals – infected
with a filovirus typically seem not to become immune to it for long, which make
it hard to imagine and effective vaccine or other forms of cure.
The first ever documented major outbreak of Ebola happened
back in 1976 in Zaire where the pathology of the virus was first discovered. It
was the 1995 Ebola outbreak in Zaire that first raised global concern and
concerted research for the cure of the disease. The fatality rate of the
disease approached 90-percent, though horrendous to the infected, it’s the very
characteristic of Ebola that limits its spread – i.e. infected individuals die
before they can pass on the disease. The only consolation is that the Ebola
virus is relatively hard to transmit, apparently requiring either exposure to
infected blood products or very close contact with a sick individual.
ZMapp drug has just recently proving its effectiveness in
curing the early stages of Ebola after an American health worker working in
Liberia named Kent Brantly received the first dose of the drug nine days after
falling ill. ZMapp drug is being developed by Mapp Biopharmaceutical, Inc.
ZMapp is composed of three humanized monoclonal antibodies (mAbs) that combine
the best components of MB-033 (Mapp) and ZMab (Defyrus /PHAC) each of which
were combinations of mAbs.
Even though the latest monoclonal antibody based Ebola cure
called ZMapp proved to be very effective in curing Ebola, it is quite expensive
and slow to manufacture because its production involves farming / as in
“pharming” its active components from a genetically modified tobacco plant and
is still largely untested. Not surprising since the company who developed it is
so small it is only composed of nine individuals. Given our current lack of
knowledge on the nature of filoviruses, it might be awhile before medical
science can develop an Ebola vaccine that is as inexpensive and as effective as
the polio vaccine currently in widespread use.
