BY DR SIVA KUMAR
Viruses are such tiny particles that tens of millions of viruses will fit on the head of a pin. Their size can range from 20 to 300 nanometres (one nanometre is equivalent to 1/1,000,000,000m).
Viruses, which means poisonous substances in Latin, were early on thought to be poisonous chemicals and therefore, in 1946 when Stanley and his colleagues successfully isolated a virus, they were given the Nobel Prize in chemistry and not in physiology or medicine.
Scientists have been puzzled for the past 100 years about whether to call viruses poisons or life-forms or molecular machines produced by nature’s own nanotechnology. Viruses behave as non-living things consisting of inert nucleic acids (DNA or RNA) enclosed in a coating, like seeds, but when they enter a living cell, called a host, they shed their coat and behave as if they are alive.
Although viruses live a kind of borrowed life, they affect cells’ replication machinery to sustain, reproduce and colonise. Viruses can infect any organism; from bacteria to elephants, plants to people. The common cold, warts, diarrhoea, and encephalitis are some of the infections caused by them.
Viruses are so smart they don’t leave any trace of their origins because they not only copy themselves within their host cells but also stitch their genes to those of the cells they have infected. Each targeted cell may become a virus factory and release new viruses to infect other cells. During this process, they can kill, damage or modify the infected cells and make us sick. Different viruses target different cells such as the liver, respiratory system or blood. For example, the Hepatitis B virus affects the liver, and the polio virus affects the nervous system. During an infection, our body may have several million viruses in every drop of blood.
An infected person, as a reservoir of viruses, can release them in bodily fluids – through coughing and sneezing – or by shedding skin or even by touching. These infections spread further and can be sporadic (less frequent), clusters, or endemic (a constant presence over a geographical area). They can become an epidemic (sudden increase), and when it affects a whole country or the world, it is called a pandemic.
There are no treatments for most viral infections; we simply need to wait for our immune system to act against the viruses. In fact, once infected, a war starts against the invaders as our body produces antibodies to fight them. There are around 30 million unique antibodies with different shapes in our immune system that are produced at a rate of 2000 molecules per second. Just two antibodies are enough to handle a virus. Once an antibody marks the virus, white blood cells engulf the virus and send it to the cell recycling system.
Coronavirus was first isolated in 1937. Doctors now recognise that several types of coronavirus can affect humans. Most strains of coronavirus cause the common cold, but some rarer strains cause
Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS) and Coronavirus disease (COVID-19).
Social distancing is considered to be an effective way to contain the transition when the disease is spread by droplet, as in the case of COVID-19. Even two or three weeks of strict social distancing can prevent a sharp peak of infection.
The human race has fought several pandemics over time and has become stronger in the process. During this crisis, too, there are many positive reports about recovery and rapid progress being made in the discovery of antigens and vaccines.
To overcome the global pandemic affecting the planet Earth, it is very important to adhere to the guidelines issued by officials and medical authorities and to strictly practise social distancing.
Someone posted the following on the social media:
This coronavirus has a big ego. He will not come to your house unless you go out and invite him.