Coronavirus is proving to be something like the demon
Raktbeej of Hindu mythology. Each time its one variant is mortally wounded, the
virus mutates and multiplies at a terrifying speed. So, there is any number of
variants. The latest to catch attention is C.1.2 variant which is changing and
mutating at an alarmingly rapid rate. It was first detected in China, South
Africa and England in June 2021. However, there is no evidence yet of it
turning into a pandemic. Some experts feel that this variant may not travel far
and may die soon.
Pandemic, Epidemic and Endemic
A contagious disease tends to spread far and wide. But
not all contagions have identical reach. It is a pandemic when an infection
spreads across several countries and continents, as COVID-19 has done. However,
certain diseases, which may or may not be contagious, do not go beyond a
community or a region. These are called epidemics. Smallpox,
plague, measles and polio are prime examples of epidemics. However, an
endemic is a disease that becomes a constant feature in a particular community
or region. For example, dengue and encephalitis in certain parts of India
during or immediately after the monsoons. So, an endemic disease may appear and
disappear seasonally in the same population. Unlike pandemics and epidemics, an
endemic is predictable.
What is Coronavirus?
We all know that coronavirus first appeared in China’s
Wuhan province during the second half of 2019. Thereafter, it spread across the
globe at a mindboggling pace, destroying lives and economies all over the world.
Coronavirus is essentially of three types: SARS, MERS and COVID-19. They belong
to the family of RNA viruses that attack a person’s respiratory system. These
can prove fatal too. RNA viruses have ribonucleic acid as their genetic
material.
SARS or Severe Acute Respiratory Syndrome spreads
through talking, sneezing and coughing. Right now, its fatality rate is about
9%.
MERS or Middle Eastern Respiratory Syndrome also
spreads through the respiratory droplets from the nose or mouth of an infected
person. People above 60 and suffering from diabetes or hypertension are more
vulnerable. Its mortality rate is 34%.
COVID-19
is the latest version of coronavirus. It is closely related to SARS and certain
types of common cold. CO' stands for corona, 'VI' for virus, and 'D' for
disease. Formerly, this disease was referred to as '2019 novel coronavirus' or
'2019-nCoV.' It spreads through the
respiratory droplets released from the mouth and nose of an infected person
just as in the case of SARS. Shortness of breath and dry cough are two major
symptoms of Covid-19. People above 65 years or suffering from any medical condition
or immunity deficit are at a higher risk of catching COVID-19. It has a
comparatively low fatality rate of 3.4%.
Recently, the World Health Organisation notified
the Mu as a variant of interest. It was first found in Colombia in January
2021, and has been found in about 39 countries so far. It might be able to
evade some of the protection provided by COVID vaccines. However, it doesn't
seem to be outcompeting Delta, the dominant variant across most of the world. A
variant of interest is the one that the WHO identifies as capable of harming
people’s health. Eta, Iota, Kappa and Lambda are the other variants of interest.
The Delta Variant
Right now, Delta is giving a tough time to
scientists and virologists. Viruses
evolve to become more infectious, but less virulent over time. This virus has
evolved to become more infectious and more virulent. The Delta is radically
different from the virus that appeared in Wuhan, China, in late 2019. This
variant has had so much time to mutate that it has become nearly impossible to
control it effectively. It has developed capabilities to merge with other strains
and thus avoid human immune systems – at least partially if not completely. But
this is enough for it to change the course of the pandemic.
Andrew Read, an evolutionary biologist at Pennsylvania
State University says, “We’re much better at explaining the past than
predicting the future. It’s very, very tricky to know what’s possible, until it
happens. It’s not physics. It doesn’t happen on a billiard table.” Evolution,
after all, is driven by random mutations, which are impossible to predict.
In the US, it has been discovered that the Delta
strain’s ability to mutate at a rapid pace has reduced the effectiveness of
most vaccines to 60%. During a press briefing at the White Houser, Dr Vivek
Murthy, the surgeon general, said, “We are concerned that this pattern of
decline we are seeing will continue in the months ahead, which could lead to
reduced protection against severe disease, hospitalisation and death,”
However, there is a silver lining. The current spikes
in cases and deaths are the result of a novel coronavirus meeting naïve immune
systems, which are not used to such a contagious invasion of the human body.
But when enough people have gained immunity through either vaccination or
infraction the coronavirus will transition to what epidemiologists call
“endemic”. It won’t be eliminated but it won’t disrupt our lives anymore.
There will be fewer hospitalisations and fewer deaths
from COVID-19. Cases may continue to rise and fall seasonally, but the worst
outcomes will be avoided. Assuming that the COVID-19’S ability to mutate is not
infinite.
How will the virus behave?
Dhruv Khullar, a physician and an assistant professor
at Weill Cornel Medical College, explained in the New Yorker that there are
three ways the coronavirus will continue to evolve.
·
First,
the virus simply fails to find a way to escape vaccine-generated immunity as
had happened with measles, mumps, polio and smallpox.
·
Second,
the virus manages to partly evade the vaccines’ protection, but at a price (a
decline in infectiousness or lethality, for example). This scenario occurred
with HIV in the 1990s when the virus developed a mutation that increased its
resistance to an antiviral drug but lowered its rate of replication inside the
body.
·
Third,
the most concerning, the virus manages to find a way around vaccine-generated
immunity while maintaining – or even gaining – transmissibility or lethality.
The Antibodies
No vaccine is perfect. A small number of people get
hospitalised with COVID-19 or even die after being vaccinated. These people
often have other health conditions. The variants could cause the vaccines to
lose some of their effectiveness and cause symptomatic disease at higher rates
and even increase the rate of severe disease or death. It would be nightmarish
if the virus changes in ways that completely escape immune response while
preserving its lethality and transmissibility. However, scientists dismiss such
a scenario as unlikely. They point out that future variants could dent some of
the defences, but the immune response should still generally be able to protect
us against severe disease.
Our first line of defenders is antibodies, some of
which are trained to recognise specific components of the virus and prevent it
from infecting cells. If mutations change those components then perhaps the
antibodies geared to identify the virus might be fooled. However, the search
for the perfect vaccine is going on at a feverish pace.
The Perfect Vaccine
A study
published in the scientific journal Molecules states that the molecule produced
by the jararacussu pit viper inhibited the virus's ability to multiply in
monkey cells by 75%. This snake is found in Brazil and measures up to two
metres. Rafael Guido, a University of Sao Paulo professor and an author of the
study, told Reuters, "We were able to show this component of snake venom
was able to inhibit a very important protein from the virus."
Then there is the llama – a beautiful animal found
mainly in Bolivia, Peru, Ecuador, Chile and Argentina. Along with soulful eyes,
long necks and fuzzy coats, llamas have a less known gift, they make an array
of immune system antibodies that can dismantle an invading virus. Researchers
have earlier held that the elusive universal flu vaccine can come from the
llama blood.
According to scientists, llama have antibodies called
nanobodies, which could be used to neutralise not just the original coronavirus
strains but also its emerging variants. Llama nanobodies are much more stable
than human antibodies, which can play a vital role in fighting COVID-19
globally. Researchers from the VIB-UGent Centre for Medical Biotechnology say
antibodies extracted from a llama have blunted the virulence of coronavirus
infections, including variants, in laboratory testing. The technology, which
would supplement rather than replace vaccines by protecting people with weaker
immune systems and treating infected people in hospitals is a potential
game-changer.
Well, let us hope this comes true, and this 21st-century
Raktbeej demon is finally slain, never to terrorise humanity again.
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