Getting Technical
by human bodies. The answer to the question as to how long
are we going to have to live in this new "coronaworld"? would
therefore seem to be – probably for the foreseeable future.
Looking for up-to-date information on coronaviruses, one
is confronted by articles, analyses and opinions containing a
mass of technical terms familiar only to people who have at
least a basic knowledge and understanding of this particular
area of microbiology. This is also evidenced in general print and
electronic media which cover news of effects and consequences
of infected people but present virtually no information on
characteristics and properties of the virus itself. One of the
frequently used technical terms is ‘genome’ which is not only
used in microbiology but widely used throughout the whole
subject of biology as the detailed listing of the complete set of
genetic information of any biological organism.
A high-quality, easy-to-read article entitled "Genomic Study
Points to Natural Origin of Covid-19" was recently posted by
Francis S. Collins, M.D., Ph, D. who was appointed as the 16 th
Director of NIH (National Institutes for Health research in the
USA) by President Barack Obama in 2009 and continues to
serve in this capacity under the administration of President
Donald Trump. The opening two paragraphs are as follows.
"No matter where you go online these days, there’s bound
to be discussion of coronavirus disease 2019 (COVID-19).
Some folks are even making outrageous claims that the new
coronavirus causing the pandemic was engineered in a lab
and deliberately released to make people sick. A new study
debunks such claims by providing scientific evidence that this
novel coronavirus arose naturally.
The reassuring findings are the result of genomic analyses
conducted by an international research team, partly supported
by NIH. In their study in the journal Nature Medicine, Kristian
Andersen, Scripps Research Institute, La Jolla, CA; Robert Garry,
Tulane University School of Medicine, New Orleans; and their
colleagues used sophisticated bioinformatic tools to compare
publicly available genomic data from several coronaviruses,
including the new COVID-19."
The international research team began by studying the sections
of the coronavirus genomes which cause the spikes that
give these viruses their distinctive appearance resembling
crowns – the word ‘corona’ being the Latin word for ‘crow’. All
coronaviruses use spike -type proteins to penetrate and infect
cells of organisms and over time, the various coronaviruses have
constructed their own spike proteins so that they are different
from each other. These differences can be seen as defined in
their genomes.
The genomic data of the new coronavirus responsible
for Covid-19 demonstrates that its spike protein enables
this coronavirus to bind to a specific protein on human cells
called angiotensin converting enzyme (ACE2). This is a similar
activity that another coronavirus has that causes severe acute
respiratory syndrome (SARS) in humans.
Previous computer models had predicted that this new type
of coronavirus would not bind to ACE2 as well as the SARS virus.
However, the researchers found that the spike protein of the
new coronavirus actually bound far better than the computer
predictions providing strong evidence that the new virus was
not the result of any deliberate manipulations in a laboratory. In
fact, the research team concluded that any bioengineers trying
to design a coronavirus that threatened human health would
be very unlikely to have chosen this type of conformation for a
spike protein.
“In common with almost
all diseases caused by viruses,
there is not yet a cure,
as such, for AIDS.”
The researchers went on to analyse genomic data related to the
overall molecular structure, or what is called the ‘backbone’ of
the new coronavirus. Their analysis showed that the backbone
of the new coronavirus’s genome most closely resembled one
of a coronavirus discovered in a bat after the Covid-19 pandemic
began. However, the region that binds ACE2 indicated a novel
virus found in pangolins, also called scaly anteaters. These
findings are strong evidence that the coronavirus that causes
Covid-19 originated in nature. In the event that the new
coronavirus had been deliberately manufactured in a laboratory
it is far more likely that the backbones of coronaviruses already
known to cause serious diseases in humans would have been
used for this purpose.
The researchers were not able to provide a direct answer as to
what the natural origin of the novel coronavirus COVID-19 is but
proposed two possibilities.
The first is that as the new coronavirus evolved in natural hosts
such as bats or pangolins in which the spike proteins mutated to
be able to bind to molecules similar in structure to the human
ACE2 protein. This proposal would fit in with the more recent
outbreaks of coronavirus-caused disease in humans, such as
SARS, which arose from civet cats and Middle East respiratory
syndrome (MERS), which had proliferated in camels.
The other proposal is that the new coronavirus was
transmitted from animals into humans before it had become
capable of causing human disease. Then, as a result of gradual
www.hvacronline.co.za RACA Journal I September 2020 41