Will the COVAXIN or ZyCov-D will mark the beginning of the end of COVID pandemic?
The Ministry of Science and Technology thinks so, which explained in details how the human trial of the Indian vaccine would make a great change
An article written by the Ministry says that the vaccine under trial would inactivate a
whole virus with heat but would keep the antigen molecular structures intact. However,
the inactivated virus will not be able to infect or cause disease, as it is no
longer functional. The Vaccine used a virus isolated from an Indian patient by
the National Institute of Virology to develop the inactivated virus vaccine.
After much criticism in the media, which
questioned how Indian Covid-19 Vaccine would come so early, the Ministry of
Science and Technology, Government of India, has come up in support of the Indian Vaccine under trial and write an article
explaining how India vaccine may make the beginning of the end of COVID 19.
In India two vaccine have been under trial,
one COVAXIN developed by Bharat Biotech and second ZyCov-D Vaccine developed by Zydus Cadila.
The Ministry in its article written by Dr TV Venkateswaran has claimed that the human trial (nod for which has already been given by the Drug
Controller General of India CDSCO--The Central Drugs Standard Control
Organisation) has marked the beginning of the end.
The
article in detail explains, the vaccine race world over, how our Immune system
works, Immune System memory and vaccine, and ultimately How these
vaccines work.
The article said the vaccine for COVID 19 might be developed anywhere in the
world, but without Indian manufacturers involved the production of required
quantity is not going to be feasible.
Here are the details given by Dr TV
Venkateswaran .
Vaccine
race
More than 140 candidate vaccines
are under various stages of development. One of the leading candidates is
AZD1222 developed Jenner Institute of University of Oxford and licenced to
AstraZeneca British-Swedish multinational pharmaceutical and biopharmaceutical
company headquartered in Cambridge, England. The MRNA-1273 vaccine developed by
Kaiser Permanente Washington Health Research Institute, Washington and taken up
for production by the US-based Moderna pharmaceutical is just a step behind.
Both these firms have already inked an agreement with Indian manufacturers for
production of the COVID vaccines.
Parallelly Indian institutions have also engaged in
R&D for the development of vaccines in India. With the primary scientific
inputs coming from institutions like Pune based ICMR institution National
Institute of Virology and Hyderabad based CSIR institution Center for Cellular
and Molecular Biology, six Indian companies are working on a vaccine for
COVID-19. Along with the two Indian vaccines, COVAXIN and ZyCov-D, the world
over, 11 out of 140 vaccine candidates have entered the human trials.
Immune
system
Antigen from the pathogen and antibodies produced by the
human immune cells can be thought of as matching the compatible pair. Every
pathogen has specific molecular structures called as antigen. They are like the
surface with a particular hue and design. Once infected by the germ, the human
immune system develops antibodies that match the antigen.
Just as the retailer of design matching material
stockpile hundreds of design pieces of riots of colours and hues, our immune
system has ten thousand types of antibodies. If the pathogen is a known enemy,
the immune system can pull the matching design piece from the stock. Once the
match is made the pathogen is inactivated. No longer it can infect.
However, if the microorganism is unfamiliar, and mainly when it has evolved for
the first time, there is no matching colour and hue in the repertoire.
Nonetheless, unlike the textile, the antibody can evolve. At first, near
matches are tried. After various cycles of antibody development, the best fit
matures. The time lag between the identification of the main surface colour
that is an antigen, and finding a pairing design piece, that is antibodies, is
what makes the infection mild or severe. If only the immune system can
neutralise the germ instantly, the infection can be prevented.
Immune
System memory and vaccine
Like a new hue of design piece once acquired is stocked
for future, once the new antibody matching the antigen evolves, it is retained
in the immunological memory. Next time the same pathogen invades, immunological
memory gets activated, and twinned antibody is released. The infection is nipped
in the bud. We acquire immunity.
A vaccine is a method to artificially inducing the
immunological memory. Once the antigens of the nasty pathogen are introduced,
the immune system is triggered into developing pairing antibodies and
immunological memory.
There are many ways in which one can artificially stroke
the immune system to develop antibodies and memory. The bottom line is
presenting the antigens of the novel coronavirus to the human immune system.
From adenovirus-based live-attenuated virus to recombinant genetic technology
is used to develop several types of vaccines. Two among the various
possibilities produced in India are inactivated virus vaccine and DNA plasmid
vaccine.
How these vaccines work
We can inactivate a whole virus with heat or formaldehyde
(that is 'killed'), yet keep the antigen molecular structures still intact.
However, the inactivated virus will not be able to infect or cause disease, as
it is no longer functional. The Bharat Biotech's COVAXIN uses the virus
isolated from an Indian patient by the National Institute of Virology to
develop the inactivated virus vaccine.
Novel coronavirus infects the human cells with the help
of its spike proteins. The spike protein of the virus binds with the ACE2
receptors on the surface of the human respiratory tract cells. Once the virus
fuse, the viral genome is slipped into the human cell where around a thousand
copies of the virus are made in just ten hours. These baby viruses emigrate to
nearby cells. Infection can be arrested if only we can deactivate the spike
protein of the novel coronavirus. Thus the antigen on the spike protein
is a crucial vaccine target. If the antibody blocks the spike protein, then the
virus cannot bind the cell and multiply.
The genomic code of the spike protein is spliced into a harmless DNA plasmid.
This modified plasmid DNA with the genetic code of viral spike protein is
introduced into the host cells. The cellular machinery translates the DNA and
produces the viral protein encoded in the genome. The human immune system
recognises the alien protein and develops a matching antibody. After this
vaccination, if at any time, we are infected by the novel coronavirus, then
sensing the spike protein antibodies are released instantly. The immune killer
cells seize deactivated viruses. Contagion is arrested even before infection
sets in.
the article is based on the information given by the Ministry of Science and Technology, Indian Government.
BY Vijay Thakur, Special Representative, The Statesman, vijaythakurx@gmail.com
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