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| Scanning Electron Micrograph of Ebola Virus (NIAID, NIH) |
It was less than
a year ago that the world seemed to be on the brink of catastrophe. There were predictions
that hundreds of thousands around the globe would die from Ebola which, at the
time, was raging in West Africa. Ebola, named after the river in the former
Zaire near which the first recognized outbreak occurred in the 1970’s had, and
still has no known cure. In an outbreak of the magnitude that was developing in
West Africa, experts from all around the world were floundering as to how to stem
its menace: Anyone that came into contact with body fluids of an infected
individual was at considerable risk of becoming a patient too and became primed,
thereby, themselves, to spread the disease in ever expanding ripples of
contagion. That kind of infectivity, coupled with the ways in which the disease
manifests itself - the fever, the diarrhoea, the vomiting, bleeding and
bloodshot eyes, collapse in the streets- induced a state of terror that was almost
medieval in scale.
Things were not
helped by how some sectors of the press stoked up fear by publishing irresponsible
statements and wild speculation. As the epidemic progressed, it appeared once in
America, that sanctum of wellness and purity: If the walls of citadel America had
been breached, where else was safe? Civilization was at the brink. It seemed
that the world would regress back to the Dark Ages in the short space of a few
months.
But
nothing like that happened, we are relieved to say. Instead, cool scientific
heads systematically considered options. The real challenge was in the
outbreak’s epicentre, West Africa, where serious obstacles stood in the way of
coping with an epidemic of the scope that was this outbreak. Nevertheless, with
public health and acute medicine specialists hanging heads, and with generous
support from world governments and medical charities, it was hoped that the
disease would remain largely confined to the three countries where it raged, even
in the absence of specific treatment or preventive measures.
Options
for managing the epidemic that were considered include administering
combinations of so-called monoclonal antibodies engineered in plants (ZMAPP), serum
from patients convalescing from the infection, or direct anti-viral agents such
as Avigan, an experimental anti-influenza virus agent. These treatments, although conceptually sound,
had the handicap of not having been widely tested in humans before, even though
studies had shown that they were effective in animals. Another confounding
factor was that none of these treatments was available in any quantity at all. Only
a few patients, lucky enough to be carrying the right passport had the
opportunity to get access.
It would be idle
to consider the ethical issues involved in deciding who got the treatment,
where, how and when. The more important consideration was how to make the
treatments available for all in need by scaling up production to hundreds of
thousands and perhaps even millions of doses. No one wanted to put up the money
for such massive emergency production without reasonable expectation that the
products would be effective and safe when used on a community scale. But first,
it was how to get round an even greater problem namely, the idea of treating
sick patients with medicines that have not gone through the usually mandatory
phases of pre-clinical efficacy and safety trials. It was argued back and
forth about where the ethical balance laid between trialing treatments that had
not gone through the preliminary stages of evaluating safety in sick patients and
thereby putting them to unknown hazards on the one hand, while on the other, worrying about the
ethical soundness of not treating people who were dying just because we were too
timid to try 'newly-hatched and un-fledged
remedies'.
However, in the
confusion, the well-founded principle that viral diseases are better prevented than
treated was not forgotten. But here again, it was not such an open and shut
case either because, although candidate vaccines were available, they too, had
not undergone the rigorous pre-clinical trials to confirm their safety. So, you’re
damned if you do and damned if you don’t.
As
it has turned out, we escaped damnation alright: the ordinary barrier
procedures surrounding nursing, and burial of the dead, gradually ensured that
disease transmission was interrupted among those caring for the sick and the
dead whilst quarantine, an always inconvenient imposition, ensured that community
transmission was curbed. Thus, by time of this writing, the incidence of new
cases in West Africa has sunk to zero. And at this time too, the CDC reports a
total of 27,988 cases worldwide, with11, 299 dead (CDC Ebola Update 3rdWeek August 2015).
The figures are horrible enough, but considerably less dire than the holocaust predicted
a few short months ago.
The
rapid fall in the numbers of affected individuals and people at risk had meant
that testing other therapeutic measures would prove difficult, not to mention
the ethical difficulties that I referred to earlier. But researchers from the WHO,
United States, South Africa, Switzerland and Mali, crafted a field trial in
Guinea of such elegance (dubbed with the slogan Ebola ça Suffit by the investigators)
that issues of ethics and falling numbers could not stand in the way of
demonstrating a 100% effectiveness of the trial vaccine, rVSV-ZEBOV (Ebola ça suffit).
There
has been much jubilation, rightly, at this breakthrough, achieved so quickly and
against such odds. But perhaps there should be a note of caution. This is because
there have been reports of a “post-Ebola” syndrome, consisting of arthritis,
hearing loss and visual problems. And we should note that preliminary studies to determine
the rVSV-ZEBOV best dose for the Ebola ça Suffit
trial showed that at a certain level, some recipients developed arthritis,
requiring scaling down of the dose.
The question that arises then is, if rVSV-ZEBOV is approved for general use, could there be a risk, in the long term, of similar complications developing in those receiving the
vaccine?
Tell Fren
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