The Wave Theory of Coronavirus

Comments of people (including experts) in media and social media has made me realise that there is still very little understanding about SARS-CoV-2 and Covid-19 pandemic. I see a lot of ignorant or irresponsible comments about virus spread, vaccines, lockdowns, as well as blaming/crediting someone for various aspects of Covid-19. So, I want to try to explain some of these in simple language and hope it benefits. I will start with waves of pandemic, as that is the hottest topic right now.

A pandemic wave does not start because someone left a gate open somewhere and virus creeped inside, neither does the wave end when all the virus has been captured and put in prison or banished. No Sir! It is not even that there should be a lot of active virus for a wave to begin and less number of virus at the end of the wave. It is just the opposite. A wave can start with just a single virus and it will end when there are trillions and gazillions of active virus around. People in India must have seen in 2020 that our cases kept rising even during a strict lockdown but as we continued to open up, the cases began to reduce — quite against common logic. Well, that is what I want to explain today.

The SARS-Cov-2 virus, commonly called ‘the’ coronavirus these days, has two basic instincts — to survive and to multiply. In that regard it is not very different from common living beings — even though coronavirus itself is not a living being, technically. It can survive on surfaces, suspended in the air, riding on dust particles etc. for various lengths of time. But inside the body of a host (humans, in this case), it can survive for very long periods. This is where it multiplies too. In other words, the basic instincts of a virus continuously drive it to find a host where it can survive and multiply. The coronavirus will continue this relentless pursuit of humans till eternity. We have no chance of stopping it considering how many different ways it spreads in and how fast it infects the hosts.

The only way the coronavirus will stop to infect people, is when it finds no people to infect. That situation can be achieved in two ways — either artificially or naturally. Example of artificial means is the strict lockdown in Hubei province in early 2020 where people to people contact was restricted so drastically that virus could not spread. Even then, there was still some spread that continues till today. The natural method is what is called herd immunity, when a high proportion of the population is already infected (and has antibodies), so that the coronavirus cannot enter their bodies to survive and multiply.

A wave of the pandemic ends when there is partial and localised herd immunity in its area of spread. The wave will typically start with one or a few virus and a single infection, increasingly infecting more hosts as days and weeks pass. But Covid-19 is largely a hidden disease and most people (80% or more) remain unaware of the infection or they will mistake the symptoms for common cold etc. When the infection has been spreading like this for months, it reaches a stage when thousands of new hosts are infected every day and hundreds of them experience symptoms and have to visit the hospital. By that time it is already too late to stop it. The Second Wave in India began exploding around 10 March 2021, which means that the initial infections leading to the wave may have started in October — November of 2020 which is the main holiday and festival season. Once the explosive phase is set into motion, it will continue till it reaches a stage of partial herd immunity when the virus can find very few new hosts, and then it begins to slow down. The same happened during India’s first wave too, but in 2020 the disease mostly remained in some urban pockets and hence affected very few people. The second time around it has spread to tier 2 and 3 towns as well as villages giving it a huge population of hosts to infect. This will also slow down in time, naturally. The countries which carried out speedy vaccination have artificially increased the number of people with antibodies, resulting in further slowing of the spread.

But it will be fatal to think that because a wave has slowed down or ended, so the virus has gone away. On the contrary, there is a larger number of virus around. So the end of a wave is the most crucial time when individuals must take precautions. That is the time the virus must desperately be looking for hosts without antibodies in order to survive. By this time, people who were infected early in the wave may again have become vulnerable with their antibodies losing efficacy over time. Or the virus may have adjusted and mutated to infect even those with antibodies. In most countries, the end of restriction periods is marked by a sudden increase in people to people contact which gives the virus the opportunity to spread again. That is what leads to the subsequent wave.

If precautions are not taken when the second wave in India slows down or ends, it will be the reason for the third wave. It is this time when the cautionary message from the govt should be the most clear and unambiguous. If leaders and politicians start congratulating themselves for something they had no hand in, since the wave ended naturally, they will only be supplying more guinea pigs to the coronavirus. But irrespective of the government, the people have to be most cautious during that time. Universal mask rule is something that cannot be ignored at any cost — no matter if the person has been vaccinated or has survived a bout of Covid-19. The ‘end’ of coronavirus is not in sight in the near future. So utmost vigilance and precautions must continue.

Originally published at on May 20, 2021.