covid-19

Was coronavirus created in the laboratory? Will those who have been infected become infected with mutated COVID-2019? Should we expect the second outbreak in the fall? And will coronavirus infect two-thirds of the world’s inhabitants? We understand together with experts.

This year marks 10 years since the first time in the history of mankind, scientists created in the laboratory the genome of a living organism – bacteria. She was named Cynthia, and the creators were a team of researchers led by an American geneticist, biotechnologist and one of the leaders of the project for decoding the human genome Craig Venter. Now conspiracy theological versions have appeared: they say that a new coronavirus is also created in the laboratory. Scientists refute: in this case – definitely not. But questions remain. We asked them a world-famous scientist, evolutionary biologist Georgy Bazykin .

George, clarifies that an evolutionary biologist: Since bacteria were successfully constructed, can viruses be synthesized in principle? Now or in the near future?

In theory, the viral genome can be synthesized. But the genome of the coronavirus that causes COVID-2019 is similar to many viruses we have seen earlier. And in nature – in bats and other animals, and in humans: it is very close to the virus that caused SARS in 2002–2003. He was also officially named: SARS-CoV-2. Studying the genome of this virus, we see no traces of intentional change – only traces of natural evolution. Furthermore, synthesizing a virus from scratch is very expensive and time-consuming. This is why obtaining a coronavirus sample is so important to make a vaccine. Although we have the complete sequence of the genome of this virus (China shared it with the whole world back in January, the author’s note), taking genetic data, synthesizing the virus quickly, propagating in cell culture, and creating a vaccine Is impossible. Theoretically feasible,

Let’s take a closer look at the enemy. COVID-2019 causes that the virus belongs to the group of RNA viruses, and there are also DNA viruses. What is their difference and why is it important for us?

Viruses are divided into two large groups that they use as carriers of their genetic information based on the molecule. Rna virus known to mankind is known for being the fastest moving (reinventing) biological objects of all. These include influenza, HIV and new coronavirus. The mutation rate of coronavirus COVID-2019 is similar to the influenza virus. This means that when we have a vaccine against coronavirus, then perhaps it will need to be updated from time to time – just like with the flu. Because if the new coronavirus becomes endemic in the human population, it will become obsolete.

That is, if “foreign” is conducive to permanent residence among people? And does it depend on whether it will happen or not?

If it is now possible to extinguish all the outbreaks and the coronavirus does not jump from animals to people again, then it will not become endemic. But one of the scenarios, which seems realistic to me, looks like this. If the mortality rate from coronavirus COVID-2019 is now correctly measured and relatively low, its fate may be like swine flu. Remember there was a flash in 2009? Earlier, he was also very scared. The disease spreads quickly and according to earlier data, it seemed that the mortality rate due to swine flu was very high. Then it turned out that the indicators are low. Most patients survive, and the virus also lives with us. Now the same swine flu, the pandemic strain of 2009 has spread all over the world and is one of the seasonal flu strains that we meet every year. This is a regular flu vaccine, which we include in the vaccine every year. It is likely that something similar will happen with the new coronavirus.

If we continue the analogy with swine flu, there was a pandemic in 2009, a large number of patients worldwide, more than 200000 people died. What is the most realistic prognosis for the coronavirus phenomenon for you as a bioinformatics scientist?

We, being scientists, do not give predictions. And we’re creating models. There are two main ways. The first is a mathematical model for the number of cases of the disease. It’s based on an indicator of how many new people infect a sick person. If this number exceeds unity, the infection will increase and will spread until the vast majority of the population is sick and receives immune protection.

China reports that a patient infects two to three people on average.

Yes, it’s not the highest rate. I insist: this number says nothing about how deadly the disease will be. It may show how the infection will spread even in the very early stages of the outbreak before any measures are taken.

Got it. That’s why the models built by British experts look so intimidating. We are talking about hundreds of thousands of people. But the whole world is taking measures to prevent the spread of coronavirus. Is it possible, knowing this, to predict more accurately the extent of the further spread of coronavirus?

In fact, it is very difficult to take all these measures into account in the model. For example, now the passenger flow from China to Russia has decreased, but still, the planes are flying (at the time of the interview, the air service with China has not yet been terminated. Whether there has been a reduction in half, 10 times or 100 times is a completely different condition for determining the probability of infection moving to Russia. Thinner things are even harder to model. If you quarantine schools, the rate of transmission of the virus will of course decrease. How much? In China, it can be one story, in India – a completely different one. In different countries different mentality, the cohesion of people, the structure of public transport, etc. But in any case, the benefit of mathematical models is that they show us a range of possibilities. Give a picture, for which in principle you need to be prepared.

Virus infection rate

Scientists determine this figure based on how many healthy people one person infects.

  • Coronavirus COVID-2019 – 2.2 (i.e. 5 patients are able to infect 11 healthy)
  • Seasonal Flu – 1.5
  • Rhinoviruses (causative agents of colds) – 6
  • Measles (if there was no vaccination) – 12-18

The second way (to determine the spread of infection, – Ed.) Is molecular epidemiology, ”continues George Bazykin. – This is a completely new science. If you have the genome sequences of similar viruses, then by comparing these genetic data with each other, you can build an evolutionary tree. Its branches will reflect the current state – the growth or slowdown of the outbreak of infection. Then we apply mathematical methods that allow us, based on information on the shape of the evolutionary tree, to evaluate, in particular, the rate of spread of the virus among people.

And what does this model say about coronavirus?

According to the first results, it turns out approximately the same as for the growth rate of the number of infections: 2-3 infected per patient. For a more accurate construction of the evolutionary tree, we lack data from China. Coronavirus mutates, new genome sequences are needed, and the PRC is now simply not up to putting this information in public databases. Probably have to wait.

You said the virus mutates. That is, in newly ill people he is not quite the same as in the former? It turns out that it is already impossible to use virus samples isolated from patients at the beginning of the outbreak to create a vaccine?

Any biological objects mutate all the time, and the coronavirus COVID-2019 is no exception. When we build evolutionary trees, we just use the fact that strains of the same virus in different people are different from each other. This happens precisely as a result of a mutation. In general, the average patient’s sequence of the coronavirus genome now differs from that of the first patient in Wuhan by about two-hundredths of a percent. This is a very small difference. We do not know whether these mutations change the “behavior” of the virus. Perhaps they are not important at all. Most likely, people who have been ill with the original version will not be infected again with this slightly modified virus. And such a small number of mutations, most likely, should not prevent the creation of a vaccine if it is based on virus samples from the first cases. I emphasize: we can talk about this,

Will COVID-19 infect two-thirds of earthlings?

The COVID-2019 virus continues to spread worldwide. Some experts give frightening predictions of a further pandemic. Epidemiologist Advisor Ira Longini , World Health Organization adviser, said that the statistical model he constructed allows two-thirds of the world’s population to be infected with coronavirus.

“In my opinion, such a forecast does not look plausible. There are several serious arguments in favor of the fact that the incidence of coronavirus infection is unlikely to reach such proportions, ”says Artem Gil, professor at the Sechenov University Graduate School of Public Health.

Firstly , the authors of the forecast immediately make a reservation: this is the simplest model, but in fact it is very simplified. “Only one indicator was taken into account: how many healthy people can be infected by one patient with COVID-2019,” the expert explains. – According to the currently available data, this coefficient is approximately 2.2 (based on this proportion, 5 patients are able to infect 11 healthy people. – Ed.). The number is entered into the statistical algorithm and the very scary number is obtained, up to two thirds of the total population. ”

Secondly , the disadvantages of such a calculation model are that it does not take into account the most important factors that impede the spread of infection, the expert emphasizes. First of all, these are quarantine measures and restriction of passenger traffic, the movement of people. It was these measures that showed great effectiveness and contributed to the victory over the outbreak of SARS in 2002-2003.

Thirdly , another method of inhibiting the infection is individual protection measures that people around the world have begun to apply. This is the wearing of medical masks, frequent hand washing, sanitization of rooms and surfaces, limitation of communication.

Fourth, you also need to take into account the seasonal, cyclical nature of most respiratory viral infections, continues Professor Gil – Influenza, SARS (in everyday life – colds) roll in waves: the incidence increases in late autumn, winter, early spring and recedes by summer. Similarly, there was an outbreak of SARS that began in Guangdong, China in November 2002 and ended by June 2003. With a high probability, a similar fate awaits a new coronavirus. A complex of factors plays the role in the cyclical development of infections (that is, their wave-like growth and retreat. – Note. Ed.), Explains Artem Gil. – Among them are the ambient temperature, humidity, the intensity of ultraviolet radiation in the open air, the state of immunity, the concentration of vitamin D in blood plasma, and other conditions.

By the way, in any case, do not forget that for many patients, COVID-2019 still causes not dangerous viral pneumonia, and the symptoms are akin to a common cold. And even the infection is completely asymptomatic – this may explain isolated cases of registered diseases in children, virologists suggest. 

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