The outbreak of the new coronavirus infection COVID-19 in China has turned into a pandemic: new cases are being reported daily around the world. Different countries are launching coronavirus quarantine measures, while ordinary citizens are panic-buying food and hygiene products. Are their concerns justified? What is the true meaning behind the term ‘pandemic’? How does the new coronavirus compare with influenza? When will the number of cases begin to decrease worldwide? These are the topics we have been discussing with Professor Aleksei Potekhin. He is the author of a textbook on virology, Candidate of Biology and Professor of the Department of Microbiology at St Petersburg University.

What is coronavirus SARS-CoV-2?

Coronavirus SARS-CoV-2 is one of the representatives of a group of human coronaviruses. They are known pathogens associated with acute viral respiratory infections. COVID-19 is not plague, smallpox, or measles. Nor is it atypical (‘walking’) pneumonia, the outbreak of which in late 2002 was caused by another coronavirus. The current causative pathogen is, indeed, life-threatening. This is true for any pathogen which has made the jump from animals to humans, but the mortality rates appear to be moderate.

Tuberculosis, for example, or malaria, kills daily as many people worldwide, as have died from COVID-19 over the last three months. The thing is we are just not monitoring the events related to other diseases online.

Is the new coronavirus similar to the flu?

The SARS-CoV-2 virus is more contagious than flu, yet less infectious than mumps or rubella, not to mention measles. It is important to emphasise that coronaviruses differ from influenza viruses. They will not keep humanity in quarantines for years and decades. In fact, coronaviruses lack the characteristics and mechanisms that enable the high variability inherent in influenza viruses. The new coronavirus is likely to follow the usual path of such infections: the longer it uses humans as hosts, the milder the symptoms. New forms will appear rarely and they will not be able to effectively overcome the immune barrier that occurs after the first infection. However, in my estimation, the current epidemiological situation may persist for about half a year. Gradually, the COVID-19 virus will become part of the ‘viral landscape’. Many people will contract it, and then life will begin to return to normality.

What is a pandemic, and how dangerous is it?

There is no need to be afraid of the word ‘pandemic.’ It means that the incidence of infection is above what is normally expected worldwide, with a large number of people being affected. Nonetheless, it does not mean that humanity is facing the threat of extinction. The virus has spread across all continents, reaching ‘epidemic’ status in a number of regions, but this was to be expected.

But the number of cases of COVID-19 in the world scares...

We are affected by real-time updates. When we see the growing numbers of infected and dead, we mentally add the word ‘already.’ There are already 8 cases in St Petersburg, 93 cases in Russia, and 80,000 infected in China. It would be more correct to say ‘in total,’ because 80,000 cases in a population of 1.4 billion people in China over a three-month period are not that many. The panic over China is greatly exaggerated.

Who are in high-risk categories for COVID-19?

From a biological point of view, that is, if we consider humans as an animal species, the coronavirus should not be regarded as incredibly dangerous. Indeed, for people with a compromised immune system it can be as lethal as many other infectious diseases. Fortunately, children are very unlikely to get ill, although the infection can be asymptomatic. Healthy adults are likely to be able to overcome the infection without the need for hospitalisation. Some may run a low grade fever, while others may be down with flu-like symptoms. Only a few will be in hospital if the criteria for hospital admission are followed, which is patients with severe or critical symptoms. Generally speaking, the situation is not much worse than for influenza, with pneumonia being its most dangerous health complication. Judging by current statistics, people over 75 have a much higher risk of serious illness from COVID-19, especially if they have chronic health conditions. In countries where the standard of living is lower, it is people over 70.

If people can carry the virus without symptoms, does this mean that it is impossible to control the spread of the virus?

The SARS-CoV-2 virus has come to change our lives: it will not disappear, nor will it be destroyed by quarantines. There are no effective drugs against it, just as is the case with most viruses. Most medical advice is limited to supportive therapy. Most likely, a vaccine for the new coronavirus will have been developed by the summer of 2020. However, it is not until the end of this year that the vaccine will be used in clinical practice, since the clinical trials timeline cannot be shortened. Therefore, sooner or later a vast majority of the world’s population is bound to get the COVID-19 virus. In fact, this is vital because herd immunity is the best way to combat infectious diseases. The more people who get infected and develop an immune memory, the fewer number of people will be newly infected. Eventually, the disease will stop spreading, even if some of the population is not immune.

Do not give credence to the rumours of re-infections: those that recovered are bound to develop effective immunity against the coronavirus.

Why is quarantine necessary?

Quarantines are aimed at slowing the spread of the COVID-19 virus. The security measures taken in China and now taken by European countries and the rest of the world are absolutely unprecedented. Their main objective is to minimise the impact on the health care system so that the health services are not overwhelmed by the sheer number of cases they have to treat at any one time. This is what Italians are going through right now. Few of us have ever experienced a tragedy like this. Social distancing measures are to ensure that those who suffer the most acute symptoms will be able to receive the medical support they need. Many people will get infected sooner or later. The point is that we must not become ill at the same time.

Besides, we do not want to lose our elderly in the coronavirus crisis. That means that we should prioritise their safety because of their unique vulnerabilities to this virus. They may require hospitalisation in a specially equipped ward or even in an intensive care unit. We know that the number of infection wards is limited and there aren’t very many mechanical ventilation systems. Moreover, ventilators are constantly required by many other patients who cannot breathe on their own for other reasons – not because of the coronavirus.

Therefore, quarantine measures are justified. When faced with a choice between going to a bar in the evening and spreading the virus and potentially infecting an elderly person, which of us will choose to go to the bar? In other words, you may help to break the chain of transmission of the virus. You may not always have to go to work, especially if you need to go there by metro. The world will not flip upside down if you stay at home.

You mean we have to self-isolate?

There is a difference between complete self-isolation and avoiding non-essential social activities. Also, there is no good reason for panic buying and hoarding food or toilet paper. There is no need to be concerned about food supply, particularly grocery goods that are unlikely to suffer from a shortage. There is also no need to be afraid of going out or going to work if you really need to go there.

What should be a matter of concern to you is that your grandparents are at risk. It is them who’d better stay at home and socialise less. Not only should they avoid public transport, but also they should refrain from going to the philharmonic, museums and other places of cultural entertainment. Indeed, this is likely to displease them, but for the time being, they should limit their face-to-face communication with their children and grandchildren, who could carry a dangerous infection without symptoms. Explain this to your elderly relatives and friends, and try to ensure that they reduce unnecessary social contacts.