Buying time
for magic bullets against ebola
Gusti Ngurah Mahardika ;
A professor of medicine at Udayana University, Bali
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JAKARTA
POST, 21 Agustus 2014
It should be the right time to make a difference now that the
Ebola outbreak in West Africa reminds us that there is indifference in the
world. Various scientific efforts have come up with ways to combat this
deadly virus, which may not be 100 percent perfect, but could help to
minimize fatalities.
Ebola is an example of a neglected infectious disease. It mostly
occurs in poor countries in Africa that do not have resources to develop
their own vaccine or drugs. If a remedy can be made available, the countries
would not have the money to buy it. This holds true for various third-world
diseases, such as dengue fever, malaria, tuberculosis and so on.
Money really matters. The possibilities stretch from vaccines to
anti-Ebola drugs, hyper-immune sera and small interfering ribonucleic acid
(siRNA). The products have never entered the market as there is no major
interest among pharmaceutical companies to fund human trials. The cost-return
is seen to be long as it is a problem affecting the poor, while conducting
human trials would cost millions of dollars in funding.
The major interest of developed countries, such as the United
States, Canada and European states, is that the Ebola virus has the huge
potential to be deployed as a bioterrorism agent. It is plausible to think
that these countries may have surreptitiously developed and stockpiled
anti-Ebola drugs and vaccines for their own use. Their interest, therefore,
would primarily be aimed at troops or embassy staff assigned to high-risk
areas.
The major impediment in developing vaccines and drugs is Ebola’s
very high fatality rate, which can reach 90 percent. Working with such an
agent requires the highest level of biosafety, known as BSL-4, in which a
facility must have negative pressure and the operator must wear the
most-secure lab coat with an oxygen-producing machine. This kind of lab
facility does not exist in most developing countries, including Indonesia.
The first line of defense that needs to be sought for viral
diseases is a vaccine. The most promising candidates are DNA vaccines or
recombinant adenovirus and vesicular stomatitis viruses.
A DNA vaccine is a recombinant plasmid that contains the
fragment of an Ebola gene. When injected into a muscle, our cells will adopt
it and create an Ebola protein that triggers immune response.
The recombinant virus vaccine is a non-pathogenic adenovirus or
vesicular stomatitis virus that carries an Ebola gene, so as the virus
multiplies in the human body, it produces an Ebola protein that ultimately
triggers immunity to the virus itself as well as to the Ebola.
These candidates have been verified efficacious in nonhuman
primates. Published in 2003-2005, these forms of Ebola vaccine have just
undergone clinical trials.
An anti-Ebola drug is also an option. Favipiravir, a universal
anti-RNA-virus drug, may somewhat reduce the incidence of Ebola infection.
Another approach is what is called drug repurposing; that is, using approved
drugs for other illnesses to be used to create a new medication. Clomiphene and
toremifene, which have been approved to treat infertility and breast cancer
respectively, have been found to reduce Ebola in animal experiments.
Sera that contain an antibody to the Ebola protein can be
utilized as a form of therapy as well as prophylaxis after exposure. Doctors
have been treating patients with sera from people who have recovered from the
illness for millennia. Animal sera can replace human sera following
immunization with the pathogen.
Moreover, we can produce a monoclonal antibody to the Ebola
virus.
An experimental drug based on a monoclonal antibody, containing
a homogenous antibody against Ebola only and developed by
Mapp-Biopharmaceutical in San Diego, California, was first tested on two
Americans who had been infected with Ebola. Both have reportedly recovered.
We understand very well that developing and testing Ebola
vaccines and drugs is not easy. It needs modern, secure facilities and vast
amounts of money.
Nonetheless, we should strive to ensure that this Ebola crisis
does not spread beyond Africa and threaten everybody worldwide. In this
modern world, ignorance could cost the entire planet.
Clinical trials can take up to eight years or even longer before
any vaccine or drug becomes available. The ethical issue is whether we can
distribute a vaccine or drug that has not been fully tested. Can we shorten
the process? Considering the extreme threat of pathogenic Ebola, the simple
answer is we need to do our best.
Everybody will comprehend that our best is sometimes not good
enough. For a lot of people, providing evidence that the remedies are not
toxic to the human body and have no long-term side effects, to be able to
cure a small part of the victim is priceless. We are not permitting Africans
to be used as experimental guinea pigs. We lessen the sadness. We reduce the
global risk.
The best thing for Indonesia is to support African governments
to prevent and control the spread of the virus, so we should send resources
to support them.
The cost would be incalculable if the virus arrived here. At
home, the public should be vigilant and a protocol to control an Ebola
epicenter should be established. Certain hospitals at the possible entry
point may have to be prepared, and special areas within them must be fully
isolated and separated from other patients.
In terms of generating ammunition against Ebola, we should
produce preparedness remedies for prophylaxis and therapy. We don’t require a
pathogenic Ebola virus to do it. With synthetic DNA and protein technology, a
vaccine and hyper-immune inventions are doable.
In testing a vaccine’s efficacy, we should collaborate with
foreign countries and conduct lab experiments there.
Being actively engaged in a global health issue, this nation
would gain valuable experience in reducing the potentially disastrous impact
and pandemic of Ebola and other diseases. ●
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