The world has come to a standstill. A new strain of coronavirus called SARS CoV-2 that originated from the city of Wuhan, China has now spread across the globe and has caused a disease called “COVID19”. As I write this, WHO has officially declared it a pandemic. This has led to significant economic disruption across the world. As the fear of COVID19 is growing amongst common people, many questions are asked; What is coronavirus? What is a pandemic? Why is it spreading so much and so fast? Why is it so deadly? Why don’t we have a treatment? Can we not have a vaccine for this? How can we prevent this from happening again?
Well in order to understand the virus we have to do a bit of deep dive into biology and chemistry.
Our cells contain genes that are like computer programming commands. Those who know how computer programs work would understand that the language we use in computers is fundamentally very simple and made of either 0 or 1 and by designing various combinations like “01010101010” we generate various codes which are used to control various functions on the computer. Similarly, our cells contain genes that are made up of four chemical structures which we call “bases” A (Adenine), C (Cytosine), G (Guanine) and T (Thymine) in various combinations. All living organisms contain these codes. So if you are really clever and know how to write these codes you can practically create any organism as long as you have a supportive environment. The smallest living cell is a bacteria called carsenella ruddii, and that has 159,622 bases while the human cellular genome contains approximately 3 billion of these base pairs. Fundamentally, all the autonomous cells require minimal codes for replication and protein synthesis, which is required to construct the basic structures of that cell.
Viruses, in contrast to bacteria and human cells, contain similar base pairs in various numbers but they are not coded with programs and machinery (ribosomes) that are required for independent existence. This means they need support from their host 1) to survive 2) to replicate and as per stringent definition of life, they are nonliving particles. The other fundamental difference between living cells like bacteria and human cells and viruses is that living cells contain lipid or glycolipids in their cell wall, while viruses have proteins in their cell wall. Mathematical modeling of metagenomic data suggests that there are millions of different types of viruses in our ecosystem, but we only know the details of around 5000 viruses.
What is “coronavirus”?
So coming back to “Corona”. Coronaviruses are a family of different viruses, and they derive the name from the distinct crown-like appearance of their surface (corona is a Latin word for crown). Generally known to cause minor symptoms such as a cough or a cold, the first noticeable outbreak of Severe Acute Respiratory Syndrome (SARS) occurred in China back 2003, which gradually spread across the globe in about 37 countries, infecting at least 10000 people worldwide and killing about 1000 individuals. A second outbreak of severe illness that occurred in 2012 in Saudi Arabia was termed Middle East Respiratory Syndrome (MERS). Since the emergence of SARS CoV-2, scientists now have managed to decode the underlying genetic template of this new virus.
What are the new features of the SARS CoV-2 virus?
The new virus has spike-like proteins on its surface that attach to the human cell wall and open the human or the host cell like a can opener. The other district feature of this virus is the cleavage site which opens up the virus. The current understanding is that bats are the most likely reservoir of this virus and humans might have been infected through an intermediate host.
Why is it spreading so fast?
The standard influenza viruses spread with a factor of 1.3 which means after 10 cycles it would have infected 14 people while this new coronavirus spreads with a factor of 3, so after 10 cycles it has the potential to infect approximately 50000 people. Higher transmissibility coupled with current globalization has added fuel to the fire. An infectious disease that used to remain limited to a particular geographical area has now become a pandemic within a matter of a few weeks.
Why is it so deadly?
Well, it is not as deadly as SARS1 and MERS in terms of the proportion of people dying who contract it, but the major issue is its high transmissibility. If the virus is rapidly symptomatic or deadly then it kills many people quickly after infection which sometimes can be an advantage as it limits further spread. The problem with this new coronavirus is that most people either remain asymptomatic carriers or carry very mild symptoms, which in turn allows this virus to spread exponentially and eventually it kills the vulnerable people, for example, people with underlying lung or heart conditions or people who are immunocompromised.
Why don’t we have a treatment for the virus?
As I mentioned earlier, there are millions of viruses in our ecosystem and they all have their distinct way of functioning and they constantly change their genetic codes, what we call mutations. For example, there are four different types of influenza viruses (A, B, C, D) cause what we call seasonal flu, however, most pandemics have occurred when a new strain of influenza A virus emerges. While there are potentially 198 different influenzas A subtype combinations, only 131 subtypes have been detected in nature. So basically, you are fighting with an enemy which constantly changes its tactics. This is probably the reason why we have failed to develop any drug so far. Having said so, certain drugs such as Oseltamivir (Tamiflu) have some effect but against only a specific strain of influenza virus (H5N1) but are not so effective against others.
The other success stories we have against our fight with viruses are drugs against HIV and the hepatitis C virus. With Pegalyted Interferon, Ribavirin and newly developed drug Vosevi (2017), we now can treat hepatitis C with 90 % cure rates. However, this has caused an interesting dilemma for the pharma giant Gilead Sciences. With a 90 % success rate, there are fewer and fewer numbers receiving these drugs over the last few years, which has led to a sharp decline in their annual revenue from 15B USD to 8B USD. Some investors don’t like this sort of therapeutic success!
What about vaccines?
Vaccine development can be an effective strategy to prevent specific virus infection and polio is a classic example. However, an appropriate vaccine cannot be developed before a new virus emerges and can be replicated in sufficient quantities to allow the manufacturing of the vaccine on a mass scale. Moreover, vaccine development is an expensive undertaking costing approx 1Billion USD with an average 94 % chance of failure, making it an extremely “risky investment strategy”. Also, it’s impossible to predict the demand; by the time you make the vaccine, the pandemic is over.
This leads us to several ethical, financial and philosophic conundrums around the allocation of financial, scientific, medical and other scare resources.
Each pandemic costs the world more than 30–50 Billion USD. For example, the 2003 SARS outbreak in east Asia cost 54 Billion USD. The current coronavirus pandemic is likely to cost the global economy around 2 trillion USD. These costs are astronomical compared to 1–2 Billion USD cost of vaccine development. But the big question is would you put your money in any business when you have more than 90 % risk of losing your capital? I am sure most of us would not do this sort of gambling and so do investors. It’s hard to get funding for rare diseases until there’s an epidemic or pandemic.
That’s why I have the greatest respect for our biotech venture capitalists community, philanthropists like Bill Gates and the Pharma industry. They take chances by risking everything. Yes, they do make money but they continue to invest in R&D to find the next generation of drugs/vaccines. Also shouldn’t nations have a dedicated vaccine charity fund? All we need is 10 million individuals donating 100 USD each for future vaccine development. We have 47 million people with a net worth over one million USD and more than 2000 people with a net worth of over 1 Billion USD, given the implication on the financial sector, can they not come up with dedicated vaccine research fund. We easily spend 100 USD in a nice restaurant or in a night out when we are not locked down!! We simply underestimate the cost of freedom and a healthy life.
Dr Govind Chavada