The last few weeks have not only seen a significant rise in the number of people in India infected by novel coronavirus (SARS-CoV-2) but also fear and misconception about the ways the virus could spread. While it is indeed true that the virus is highly infectious, scientifically unsubstantiated beliefs about the routes of transmission have only made it worse. As a result, doctors and healthcare workers have been harassed, sick people deserted at a time when they needed care, and even funerals of victims have been violently disrupted. Yet, this phobia and stigmatisation would probably not have happened if only we would have recalled some of our high-school biology.
The virus is like a pen drive. Within itself, a pen drive contains a memory storage chip, a USB controller, some more ‘tiny nuts and bolts’ and sometimes a mini LED light . All this is encased within a metal or plastic case. It is a compact device and the only part that juts out of the case is the USB connector which can fit into the port of a desktop or laptop.
Functionally, the pen drive may contain huge data for storage, transport, copying and visualisation. But none of that can be done unless the USB connector docks onto the port of a computer. It is only then that the pen drive ‘comes to life’ and the data inside can be viewed, edited and copied.
The SARS-CoV-2 virus is very similar to the pen drive. They carry genetic material inside them (a long RNA molecule in case of SARS-CoV-2 – the viral genome) which is the blueprint for making multiple copies of themselves. However, copying this viral genome and making daughter viral particles is possible only when the spike protein (the equivalent of the USB connector) of the virus successfully binds to the ACE2 receptor protein (the equivalent of the USB port) of a host cell. Much has already been published about how the molecular interaction between the spike protein and ACE2 initiates infection of the cell and is beyond the scope of this article. Suffice to say that the docking of spike ‘connector’ on to the ACE2 ‘port’ allows the virus to kick off a series of cellular processes that finally produce plenty of viruses.
How it works
As is well known from our school textbooks, a virus hijacks the cell’s internal systems and commands it to produce only biomolecules needed for making more viruses. Finally, the infected cell bursts open and numerous viral particles are released, which, in turn, infect neighbouring cells or be carried out as part of droplets in human breath.
The organelles in a cell that are essential to produce multiple new viruses need energy; the main source of biochemical energy is adenosine triphosphate (ATP) — the universal energy currency of cells. Virus production needs ATP, but once a person is dead, the cells stop making ATP. To go back to the analogy, ever heard of a pen drive that works on a computer that is switched off and has no battery? No, that is not possible.
But why would cells would stop making ATP almost immediately after death? ATP production in our cells happens in the mitochondria, and the two main raw materials needed are glucose and fats (from our digested food) and oxygen (from our lungs). The oxygen is delivered to the tissues by haemoglobin, the oxygen-transporting protein of blood. Life, as we know it, is heavily based on mitochondrial ATP production and without oxygen, the mitochondrial ATP production comes to a halt. Whatever is already there will supply for a very short time, but that is it. That is the equivalent of ‘power off’. Hence it is a biochemical reality that a dead body cannot produce new viruses.
By Anirban Mitra.
Rooted the news desk of The Times of India (online platform), Anirban has an experience in handling the social media platform. He also covers the automobile section for the organisation.