How did Coronavirus become pandemic? Or, for that matter, when does a contagious disease become pandemic? We all know that the WHO declared it a pandemic on March 11th, 2020. But, that is not the answer that this Post is seeking. That is just the official date of birth. It tells nothing about the process. In this part of the globe, the official and the actual dates of birth may vary. As in the case of individuals, the actual date of birth of the pandemic might well be much earlier.
Before we foray further, it would be worth reminding that none of the SARS, MERS or Ebola was an official pandemic. Severe though they sure were! The last time we had a pandemic was in 2009 in the form of H1N1 influenza. So, what did make this coronavirus a pandemic?
Pandemic and its Levels
Well, first, what is a pandemic? In simple terms, a pandemic is a global (pan-world) epidemic. As it is an epidemic, the element of sudden outbursts of the disease is an inherent feature. Moreover, it has to be contagious.
Now, a contagious disease spreads in different stages. The first stage is “endemic”. They also call this the “base-line level”. This is the usual occurrence of the contagion in the population. Remember, pathogens always co-exist with us.
Then, comes the level of “epidemic”. At this stage, there is a sudden increase in the number of cases. So, we find here two words to be significant viz. sudden and number. The suddenness is encompassed by the term “outbreak”. However, in general, an outbreak of disease is localized and geographically more restrained than an epidemic.
Finally, a pandemic engulfs several countries or even continents. Its character lies in being global. Still, that is not enough. An endemic disease does not become pandemic just because it is widespread if the number of infected people is stable. A pandemic is a propagated outbreak, the propagation needing simple day-to-day contact among people, and not shared needles, etc. There looms a pandemic threat when the virus is a new sub-type of the original found in near mammals or animals, and the sub-type becomes so well adapted and entrenched to human internal eco-system that it is easily transmissible on a sustained basis. Speed and spread both are important here. If the virus is extremely virulent, its host human will die before infecting so many other people. To make a list, all of the following constitute its essential characteristics, the last being not the least important:
- Significant illness and death
- Person-to-person transmission
- A constant increase in the number of people infected
A bit of Theory – Measuring Contagiosity (R0)
So, higher contagiosity makes a disease pandemic. And, how is contagiosity measured? Contagiosity is measured in terms of R0 (pronounced “R naught”). It indicates the number of people that someone with the virus tends to infect. The epidemiologists call this basic reproduction number. Remember, this is a sheer number and not a rate of infection. R0 tells the number of unvaccinated and uninfected persons who will get infected by one contagious person. Now, there are three possibilities:
- R0 < 1. The disease will decline and eventually die out.
- R0 = 1. The disease will stay alive but the situation will be stable and there will be no epidemic.
- R0 > 1. The disease will spread and there will be an outbreak of an epidemic.
It should be remembered however that R0 is a theoretical-mathematical construct and depends on various theoretically ‘ideal’ situations like the following:
- The population is a closed one.
- No one in the population is vaccinated.
- No one has had the disease before and thus acquired any degree of immunity.
- There is no medical or socio-political or administrative intervention to contain the disease.
In a word, the definition demands that everyone should be equally susceptible. To say the least, none of these conditions ever apply in practice. Nonetheless, all theoretical constructs suffer from such assumptions and regardless of these, R0 is an important parameter. One obvious point: airborne illnesses tend to have a higher R0 value than those transmitted through bodily fluids like Ebola and HIV.
Is R0 a static figure?
R0 is a statistical estimate and a moving one. It depends on the assumptions and the quality of data. R0 also depends on the control measures being implemented. It, therefore, is subject to action taken as well as the timing of action. It may change over time.
As said above, R0 is not the only factor. Take, for instance, the case of swine flu. The R0 value of the 1918 epidemic was between 1.4 and 2.8 and the R0 value of the 2009 outbreak of the H1N1 virus was between 1.4 and 1.6. The death toll however in 1918 was too excessive – about 50 million.
Effective Reproduction Number
To overcome the limitations of the concept of basic reproduction number, they have evolved effective reproduction number ‘R’ which is the product of the basic reproduction number and the fraction of the population that is supposed to be susceptible.
Higher contagiosity (R0) makes coronavirus Pandemic
Now, an R0 greater than 1 means that counter-measures, such as quarantine, will be needed to contain the spread of the disease. For the novel coronavirus, the WHO has estimated an R0 of 1.4 – 2.5. Other teams suggest slightly higher values. These estimates are not way off the R0 figures for SARS during the early stages of the outbreak in 2002–03. Moreover, they match the estimates during the 2009 pandemic caused by a novel strain of H1N1 influenza. And, they are higher than R0 values estimated during outbreaks of the Middle East respiratory syndrome (MERS) virus, another coronavirus similar to SARS.
With a death rate of 4.5% the coronavirus does not seem to be as deadly as SARS — which killed around 10% of the people it infected. But it is highly contagious and that makes it a pandemic. Still, the virus itself doesn’t spread. As we all know, a virus is a half-dead living entity. Dead bodies don’t travel. It is we humans who spread the virus. A virus just manages to enter a human. Once inside, it multiplies rapidly. It is the infected person who infects another person. The chain continues, and it becomes a pandemic.
Will Herd Immunity save us from Coronavirus?
The concept of herd immunity is important in making public health policies regarding immunization and eradication of contagious diseases. This simply means that when a large portion of the population is vaccinated, they protect the unvaccinated small left-out portion of the population also. This happens because the chain of infection is broken at multiple points. So, epidemics don’t happen. Herd immunity also applies if a large portion of the population has developed immunity through infection itself and not through vaccination.
So, the pandemic is expected to cease to be a pandemic at some point in time. But logically, before it ceases to be pandemic, the coronavirus had to become pandemic first. At any location, it will cease to be a threat once the infection reaches its peak. That is the reason, news of too many new cases are now not coming from China. So, the credit goes as much to the cycle of infection-cum-immunity as to the quarantine efforts of the Chinese authorities. But, the problem is that by the time herd immunity starts to work, thousands would have perished. Sheer survival of the fittest! Or, the luckiest!
Can medicines be developed to treat the coronavirus?
The bitter truth is a big NO. Medical science doesn’t offer any effective drug against the common cold, caused by one of the coronaviruses. Moreover, no drugs have been shown to be effective in treating SARS or other coronavirus infections in humans, and no vaccines aimed at preventing these infections have been licensed. Moreover, by the time a vaccine is developed, the virus mutates to emerge as a new threat. Despite advances in medical science, the contagious diseases are here to stay. Apprehensions are now coming true that this novel coronavirus is set to cause a larger scale of public-health concern if nothing else happens.
Thankfully, there is a way out, however. Research is geared to finding therapies that would work by blocking the receptor on human cells that the virus latches on to and uses to infect the cells. They have used on trial basis even the existing HIV drugs such as Ritonavir and lopinavir. The Beijing branch of China’s National Health Commission has given this information in a statement. The Indian Council of Medical Research (ICMR) has also approved this drug combination for use in the cases of senior citizens infected with the coronavirus. Even otherwise, standard care including supplemental oxygen, ventilator support, and antibiotics has resulted in a good recovery rate.
As a respite, the existence of vaccines and antiviral drugs along with other advances in medical science can arrest the situation from getting aggravated. Surely, compared to 2009, in 2020 we have advanced still more. Hence, we need not panic. We are not allowed to picnic, either. We should all follow the instructions of the health authorities and abide by the directions of the politico-administrative authorities.
In the end…
So, how did coronavirus become a pandemic? – the novel coronavirus disease COVID-19 has become a pandemic not just because of high R0 factor rather more due to delayed response by governments and institutions:
- China literally shot the messenger;
- World Health Organization took time to press the panic button; and
- The national governments were too lethargic to close the airports in January.
- Moreover, governments in India have constantly been more concerned with temples and statues, and less with education, research and public health.
- It is a failure of the UN Security Council. Does security mean only security from war?
To repeat, a virus doesn’t travel by plane. The Coronavirus was co-existing peacefully within bats and pangolins. The Chinese allowed it to catch us by the throat. Therefrom affluent and knowledgeable but blissfully ignorant globe-trotters took it as luggage and dumped everywhere. The WHO and the national governments woke up two months late. That’s how the coronavirus has become a pandemic. They couldn’t restrain thousands of travelers, put their populations at risk, and are now left with little choice than locking down billions of people.
Anyway, as law-abiding citizens concerned with our health and wellness and that of our families, we must abide by the directions and follow self-isolation and social distancing to break the chain and flatten the curve. Our only concern is that 21-day may extend into literal 40-day quarantine. In emergencies, governments amass extra powers and refuse to budge even after it is over. Let’s be vigilant. Let the (State) apparatus not win at the cost of the soul (of the nation).