April 20, 2024
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By Suhotro Gorai June 2, 2020

Life originated from microorganisms and evolved into giant ubiquitous beings. Many theories surround the origin of life but it is known that microorganisms were already in attendance before anything else. Humans rose slowly down the years from ancestral monkeys and developed intelligence scarcely observed in other living beings. Human civilisation grew to protect themselves from daily body infections. Then came technological advancements resulting into abundance of diagnosis tests, treatments with different medications and therapies.

"Severe acute respiratory syndrome coronavirus 2"
SARS-CoV-2, a member of the family Coronaviridae

Despite such development, humanity momentarily is at feet of a crippling viral pandemic. Let us delve further and understand why that maybe the case. A virus is considered an infectious agent consisting of nucleic acid (genetic material) protected by a protein coat. It is very miniscule in size but can infect any large bodied organism enough to cause mortality. Though it itself can do no harm, it needs to enter or penetrate a host cell to carry out its function.

Cross-sectional model of a coronavirus
Cross-sectional model of a coronavirus

This mechanism of entry is possible by binding of viral proteins with cell surface receptors. This can be imagined as lock and key. Once the right key is inserted in the lock that is when specific proteins (key) interact with the surface receptor (lock), the cell will allow the entry of the virus. It is facilitated by fusion of the viral particles on the cell surface. The viral particles get degraded and the genetic material is now inside the host cell.

The life cycle of a coronavirus

Next process is the multiplication of viruses which begins with replication of genetic material. Following that, viral proteins are synthesized which is then assembled with genetic material for packaging. This entire process can be imagined in the form of factory. Raw materials are collected, processed and packaged to make products ready for delivery. Once viral particles are prepared, they are ready to be released from the cell outside for them to infect new cells.

Schematic representation of the genome organization and functional domains of S protein for SARS-CoV and MERS-CoV

Having understood the story of viral propagation, there is one crucial step which is a determining factor for the virus. It is nothing other than replication of genetic material. This is done using different enzymes also found in viruses. Now, these enzymes which are supposed to perform this function are error prone. That means the virus genetic material will change frequently (mutation as we say). There is no quality control present. Almost all of it is packaged as new virus particle. Once they are released and new cells are infected, viral propagation becomes subjective. If the viral mutation is detrimental for its survival, there will be no new viral particle formation. On the other hand, if the viral mutation changes it to make it better, it will attack far better and propagate faster. It comes from the Darwin’s theory of “Survival of the fittest”. That is why this new/novel coronavirus is causing havoc around the world.

The virus is fit enough to bring everyone at mercy. On the other hand, medical advancements have gradually encompassed in human life since its beginning. Diseases and humans have been together since dawn of civilization. Previous times lacked disease knowledge and was myth based. Slowly experimental science crept in and revolutionized disease acquaintance.

File:Symptoms of coronavirus disease 2019 2.0.svg
Symptoms of coronavirus disease 2019

Doctors based them on signs or symptoms with accompaniment of medical tests. Technology became advanced with tools being in use for rapid detection of infections. Scientists gradually could observe micro-organisms through lens or microscope. Edward Jenner popularised vaccination amounting to numerous vaccines for most known diseases caused by microorganisms. Patient data is now available as resource for study of disease and modelling. Epidemiologists enter into in-depth study of disease outbreaks and factorise possible strategies countering spread. Even though such humongous developments, most
epidemics are unpredictable happening uncalculated, comes unanticipated.
Similar is the devastation currently in phase with the coronavirus pandemic.

No one could predict this war of viruses on humans though we possess medical weapons but not enough to neutralise the viral enemy. This is suggestive of human lack of precautionary strategic weapons enough to nullify this current looming world gloom. Therefore, humankind left with no option but to wage an overpowering war to combat this menace, overcome the situation, learn from this crisis and fortify itself with
next-generation medical weapon to handle similar war better next time.

Let’s meet the author, Suhotro Gorai

Suhotro Gorai is a Masters student of Biomedical Sciences at the University of Amsterdam, Netherlands. He has experience in Cell Biology, Molecular Biology, Immunology and Microbiology in terms of project work and curriculum. He is actively interested in research on infectious diseases and the immune system.

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