What the world is today battling is COVID-19, caused by a notorious virus strain, belonging to the Coronavirus family, which is called SARS-Cov-2. It is one-thousandth of the width of an eyelash, and a mere non-living package of distinct genetic material. Yet, it is proving to be immortal and has brought the whole world to its knees.
Viruses that are desperate for a human host have always been a major threat to us. SARS-Cov-2, however, is a virus strain which is not only causing deaths around the world, but is also seriously challenging humanly notions of science and technology. While we as a race might think of ourselves as the repository of all worldly knowledge, when it comes to viruses, and their corresponding outbreaks, humans have always been made to bite the dust.
Does that mean that we are incompetent, and will never overcome COVID-19? No. We will. However, what damage the strain would cost us before our victory over it is something which nobody can take a bet on.
Virologists will be in love with the COVID-19 causing SARS-Cov-2 virus strain. Simply because it is proving to be a magnificent one. Unlike SARS-Cov-1, today’s strain is patient. It has mutated for the human body perfectly. It is sly and does not even make its presence known over a prolonged period of time. It has learnt the art of evading the human immune system to the extent that the incubation period ranges from 5 to 28 days! All this, while in many cases the host continues to remain asymptomatic, while also being an active transmitter.
SARS-Cov-2 is poking fun at us. It has befuddled humanity, and is continuing to belittle what we thought was our “scientific knowledge”. It has driven humans behind doors, and is causing the social animals that we are to be isolated. This piece aims at explaining how this virus strain is a force to reckon with, a force which is causing devastation of the human race.
The cases of ‘false negatives’ pose an immense threat to all countries, and can cause derailment of one’s fight against the virus strain. In science, there is always some degree of expected error. However, when the test shows completely opposite results with a sense of confidence, that becomes something to be worried about. False negative is a term used, in the present context, to indicate that the virus strain somehow was not detected during the test, maybe due to faulty apparatus, absence of the strain in the particular sample being tested, or some other unwanted mishap which might have crept in.
Such a false negative can, effectively, make everyone believe that a positive patient is in fact negative. Owing to the overloading of healthcare sector, this individual might be discharged. All this, while he/she is positive. The patient therefore sets many more transmission chains into motion. It therefore becomes important to have recurring tests conducted within a given time frame, so that the actual result may be ascertained.
Here is how SARC-Cov-2 is challenging all that we know, both about virology, as well as epidemiology. It is also showing all those over enthusiastic people a mirror, who for so long have been taking the disease for granted.
COVID-19 is highly contagious. R-naught of COVID-19 is being told to be a minimum of 3, which can also crawl up to 4. This means that one infected individual can pass on the disease to as many as three to four people. This, of course, might vary with population densities. Therefore, India needs to be all the more wary, considering the clustered populations that we have in urban pockets.
The R-naught of viral flu is 1.3 or 1.4. This means that COVID-19 is two to three times more infectious than common flu which causes cough and cold.
Professor Hugh Montgomery, director of the Institute for Human Health and Performance at University College, London, has shared some worrying insights. He has stated that since this particular Coronavirus is so infectious, almost three times more than flu, the spread of the disease which occurs due to the three patients over ten layers can end up infecting as many as 59,000 people compared to the common cold which in 10 layers infects only about 28 people!
Another cause of worry arising due to SARS-Cov-2 is its extremely flexible, and some would say, even peculiar variation of longevity on different surfaces, which can be from hours to days. Another cause of worry is also the lack of information surrounding the virus’ ability to be transmitted as an aerosol. The virus can definitely be contracted by others when an infected individual coughs or sneezes. However, to what extent the virus can spread as an aerosol released during normal breathing is simply not known yet, which makes things all the more complicated.
Studies have suggested that the virus can remain viable for a minimum of three hours in air. Therefore, contrary to popular opinion that the virus can spread only through direct or indirect contact with a patient, it now turns out that the virus strain can very much survive in air for hours, and infect numerous people while at it.
Incubation period and stealth
Any virus is not technically ‘alive’ without a host. Humans is what the SARS-Cov-2 strain requires in order to proliferate. The proliferation can take from anywhere between 5 to 28 days to complete, and consequently begin showing symptoms. Therefore, it is wrong to conclude that at the most, the strain takes 14 days for incubation.
Unlike SARS-Cov-1, the present strand does not infect the lungs directly, as that would cause immediate symptoms, hence alerting people to stay away from potentially infected patients. SARS-Cov-2 attaches itself, via its external spike present on the membrane, to a protein called ACE2, present on the surface membrane of our cells. The current strand houses itself in the throat cells first, which is the reason why many patients remain asymptomatic for a prolonged period of time, while they continue to transmit the disease unknowingly.
While not technically alive, there's an evil genius to viruses that never ceases to amaze me. It's one reason I became a virologist. A recent Nature paper reveal a remarkable trick SARS-Cov-2 learned that makes it nastier than the first SARS. Both viruses…
— Peter Kolchinsky (@PeterKolchinsky) April 6, 2020
Relapse among patients
South Korea, in the past one week, reported 116 recovered COVID-19 patients relapsing, and testing positive again. Officials are still investigating the cause of the apparent relapses. But Jeong Eun-kyeong, director of the Korea Centers for Disease Control and Prevention, has said the virus may have been reactivated rather than the patients being re-infected, reported
Infected individuals, who were previously thought to have overcome the disease testing positive after their apparent recovery is a massive cause of worry. It indicates that the treatment methods being employed are not fully eradicating the virus, but perhaps, only temporarily suspending its activity. This also means that until a vaccine is developed, the world might just continue to remain under lockdown, since only a vaccine would do enough to tame the virus and prompt the human immune system to fight it.
Now that we have brought the immune system into the picture, it is only befitting to break another piece of distressing news. Some people have been of the opinion that a large segment of people from a population being infected by the virus would ultimately develop herd immunity against the strain. As a matter of fact, the same was the UK’s policy until the realities of COVID-19 hit them hard. The foundation of such a policy was the belief that any individual once infected with the disease, who then recovers from it, develops immunity against future exposure to the virus strain. However, the relapsing of several patients is now debunking this theory. While it is possible that virus reactivated itself again within the host, there is also a chance that the people were exposed to the virus again, after initial recovery.
Moreover, herd immunity, even if developed, would be for the specific virus strain, i.e., SARS-Cov-2.
Rising chances of Mutation
If, in the foreseeable future, the present strain mutates itself into another form, such herd immunity would be rendered useless.
Speaking of mutation (the virus’ ability to bring about changes in its genetic material sequence), there are over 19 lakh positive cases around the world. Which effectively translates into the virus strain having over 19 lakh hosts. The strain therefore has the ability to mutate itself from among 19 lakh hosts.
Obviously, this presumption depends upon the time period required for SARS-Cov-2 to mutate. If the tine required for mutation is long enough, we need not worry. However, if it mutates at a rapid rate, we have a lot to worry about.
This is what we need to be scared of. Multiple reports are indicative of the fact that SARS-Cov-2, much like human retroviruses (which cause HIV-1 and 2) attacks the immune system itself.
The surprise discovery, made by a team of researchers from Shanghai and New York, coincided with frontline doctors’ observation that COVID-19 could act like a lethal auto-immune disease and cause damage similar to that found in HIV patients, South China Morning Post reported.
SARS-Cov-2 was seen to prey upon the T-lymphocytes, which form the most important component of the human immune system and trigger varied responses to foreign pathogens. The spike present on the viral envelope was found to trigger a fusion between itself and the cell membrane, following which the virus’ genes entered the T cell and rendered it useless.
SARS-Cov-2 exhibiting traits similar to retroviruses could spell a disaster for the human race. It would mean COVID-19 would cause a seemingly irreversible damage to the immune system of millions exposed to the virus. In such a scenario, humans would be prone to an enhanced rate of infectious diseases like viral flu and the likes, since the body would not be able to fight the pathogens causing the same.
Interestingly, the same experiment was carried on SARS-Cov-1, and that particular strain did not destroy T cells, which could be a possible explanation as to why the SARS outbreak in early 2000’s only claimed about 700 lives worldwide.
A simple conclusion that is derived from the points above is that humans, contrary to their beliefs, know almost nothing about the virus and COVID-19 with absolute surety. As of now, Coronavirus is an untamable horse. The only major breakthrough that can be expected is the development of a vaccine, without which, there really is nothing which we can do about the strain. Also, if SARS-Cov-2 is indeed similar in nature to human retroviruses, the development of suitable vaccines also becomes a far fetched dream. As of now, we do not know what the future holds. HIV spreads through exchange of body fluids physically. COVID-19 is spreading like common cold, at an infection rate three times more than viral flu. Only time will tell what becomes of the human race.
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