The number of people infected with coronavirus around the world is approaching one hundred thousand. Covid-19 has been identified in 76 countries. There are no special drugs against it, vaccines are undergoing clinical trials. Some believe that by the summer everything will calm down, others warn of the inevitability of a pandemic.
Quarantine is really effective
According to the WHO, the coronavirus epidemic in China has declined. A little more than a hundred new infections a day are recorded there (a month ago there were about three thousand). In other countries, the situation is exactly the opposite: if at the beginning of February several dozen infected per day were registered outside the PRC, now there are more than two thousand. Moreover, over the past 48 hours, the epidemic has spread to 9 more countries, including Poland and Ukraine.
In Russia, four cases of infection have been officially confirmed so far - two of them in Moscow. According to Rospotrebnadzor, the sick feel satisfactory, and the people with whom they contacted are identified and are under medical supervision - some in the hospital, some at home.
In addition, almost seven and a half thousand people who recently arrived from China, South Korea and Iran remain under control. Almost all of them were advised to comply with quarantine. However, there are irresponsible citizens - in the last couple of days at least three have tried to escape from surveillance. And one of the offenders is a doctor.
By February 6, 25 new cases of coronavirus infection were registered outside China. A month later, this figure has increased almost a hundred times.
“In fact, unprecedented quarantine measures have been taken in both China and Russia. And this is now the only real weapon against the coronavirus. It works very well. When borders are closed, the transmission rate of the virus decreases. If at the same time everyone wears masks, and educational institutions go into quarantine, the pathogen simply does not have the opportunity to spread quickly. If we did the same with seasonal flu, we would not have any epidemics,”said Pavel Volchkov, head of the MIPT genomic engineering laboratory, virologist.
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The carrier of the virus is contagious
According to the calculations of the London School of Hygiene and Tropical Medicine and the Covid-19 Working Group, 70-90 percent of patient contacts need to be traced to stop the disease. But even this strategy will work only if there are less than one percent of new cases of transmission of the virus before the first symptoms of the disease appear in its carrier.
On the one hand, the example of China, whose authorities have brought down the growth of infected people by strict quarantine measures, confirms this theory. On the other hand, the same Chinese doctors say that asymptomatic transmission of the coronavirus is possible. So, one of the residents of Wuhan, who came to visit relatives, infected them all. At the same time, she did not show any signs of illness, even when her family members had already turned to doctors for help. The incubation period for this patient was 24 days, which is almost double the quarantine period in many countries.
Most experts still limit the incubation period of Covid-19 to two weeks (on average, six and a half days). The virus is transmitted mainly by airborne droplets. One sick person can infect, apparently, no more than three people in an unprotected population.
Pregnant women at a later date, having received an infection, may not fear that they will pass it on to their unborn child. This was shown by Chinese doctors, observing women in labor who underwent a cesarean section.
Kisses and handshakes are canceled
There is no exact data yet on what is the proportion of direct contacts in the transmission of SARS-CoV-2 (accordingly, it is not known in what ratio infection occurs through objects). Therefore, epidemiological services, especially in countries most vulnerable to a new infection, give approximately the same general recommendations, although taking into account local nuances.
Risk of developing a coronavirus epidemic outside of China. Iran and Japan are the most vulnerable. The likelihood of an epidemic in Russia is low. Gateway for infection - the country's three main airports: Sheremetyevo (Moscow), Vladivostok International Airport and Pulkovo (St. Petersburg).
So, in France, where 212 cases of coronavirus infection have already been registered, the Minister of Health Olivier Veran urged compatriots to abandon the traditional welcome kisses la bise. Switzerland has recommended avoiding shaking hands. And the director of the department of pandemic and endemic diseases of the WHO, Sylvie Briand, even suggested several alternative ways of greeting on her Twitter.
Saudi Arabia, where one case of coronavirus infection has been recorded so far, has temporarily banned its subjects from visiting the Muslim holy Mecca and Medina.
How to use masks correctly
From the first days of the emergence of the new coronavirus, the question arose about the effectiveness of masks. The French Department of Social Affairs and Health and the US Centers for Disease Control and Prevention recommend them for prevention.
“Masks are, of course, imperfect. They "suck" a little from the sides. But if you put it on as tightly as possible, the risk of infection is reduced by an order of magnitude. In our country, buying masks is not yet relevant. Our situation with the coronavirus is not so serious,”says virologist Pavel Volchkov.
According to the head of the Department of Microbiology, Virology, Immunology of the First Moscow State Medical University named after I. M. Sechenov, academician Vitaly Zverev, medical masks do not protect against viruses as reliably as is commonly believed.
There is no specific drug against the SARS-CoV-2 coronavirus. The vaccine is still in development. Antibiotics and folk remedies will not protect against infection, but wearing masks and observing quarantine measures will help limit the spread of the disease / Illustration by RIA Novosti.
“Masks sold in pharmacies limit the penetration of the virus by about 20 percent. In addition, the dressing should be changed every two hours. As soon as it gets wet, it immediately becomes useless. Protective equipment should be worn in public transport, in premises where many people work. But on the street it makes no sense. First, the chances of catching the virus in the fresh air are minimal. Secondly, the mask makes breathing difficult, and if people have heart or lung problems, they will only get worse,”the scientist noted.
To protect against Covid-19, Rospotrebnadzor advises to observe personal hygiene more carefully - wash your hands more often, treat surfaces with disinfectants, do not touch your eyes, nose and mouth with dirty hands, and if you have symptoms of SARS, stay at home and call a doctor. Detailed preventive measures are published on the website of the Moscow City Hall.
What antiviral drugs are useless
There are no drugs to kill the new coronavirus yet. Over the past month, researchers have suggested using at least three existing drugs that have been proven safe.
First of all, we are talking about remdesivir, a nucleoside analogue that helps against Ebola. In early February, Chinese scientists showed that this drug successfully suppresses infection in cell cultures. In addition, remdesivir and related compounds have been able to cope with the highly lethal feline coronavirus. Human clinical trials are already underway in China. A week ago, the Americans also announced the beginning of testing on patients.
Other likely broad-spectrum drugs are ribavirin, ritonavir, and interferon-beta drugs. They are recommended by the Ministry of Health of Russia.
“There are a huge number of antiviral drugs in the form of nucleoside analogs - a kind of structural similarity of natural nucleotides that are used for RNA synthesis. When the virus enters the body, it multiplies very quickly. Consequently, RNA synthesis is increased. Nucleoside analogs can block it and thus inhibit the rapid spread of the virus throughout the body. But this only works if the drugs are well matched. In the case of Covid-19, this has not happened yet. Yes, some drugs show little effectiveness, but in reality they can be extremely harmful. Because the viral system very quickly leaves such nucleoside analogs - literally during the infection of one particular patient. As a result, the drug stops acting on the virus and at the same time begins to press the patient's own RNA-synthetic processes. Hence complications on the kidneys, liver and the entire excretory system. But at the moment we have nothing better than nucleoside analogues,”noted Pavel Volchkov.
As for the advertised antiviral drugs like Arbidol or Kagocel, they, according to the researcher, are ineffective in treating not only coronavirus, but also the influenza virus.
Antibiotics don't help
“As far as I know, no one seriously dealt with the cure for the coronavirus, because it did not pose a particular danger. Whether the current antiviral drugs against Covid-19 will work is unknown. But you definitely should not be treated with antibiotics, because these are drugs that act on cells, and viruses do not have a cellular structure. Sometimes antibiotics are prescribed for viral infections to prevent complications - to avoid the attachment of some kind of bacterial infection. But they have no effect on viruses themselves. You can generally raise immunity with folk remedies - garlic, milk and honey. This is, in principle, useful, but we must remember that the same garlic can negatively affect the heart rate. And some people develop serious allergies from honey,”said Vitaly Zverev.
Why you shouldn't hope for a vaccine
The beginning of clinical trials of a vaccine against the new coronavirus has already been announced by American, Chinese and French researchers. Several scientific groups are working on this in Russia at once.
At the end of January, Rinat Maksyutin, director of the State Scientific Center for Virology and Biotechnology of Rospotrebnadzor "Vector", told the publication of the Siberian Branch of the Russian Academy of Sciences "Science in Siberia" that his employees are busy creating a vaccine against SARS-CoV-2. A month later, Russian Deputy Prime Minister Tatyana Golikova, who heads the operational headquarters to combat the spread of a new infection, announced that five prototypes of the future means were already ready.
According to Pavel Volchkov, the drug will most likely be created on the basis of the vesicular stomatitis virus.
“With the help of reverse genetics technology, the virus is taken apart. A cellular system is then created, usually in vitro, to assemble the viral particle so that there is no viral genome inside. Small parts of SARS-CoV-2 are integrated into such a dummy vector. In fact, all that such a particle can do is infect cells once and deliver elements of the coronavirus there. If you vaccinate with such a synthetic virus, then a sufficient amount of neutralizing antibodies will appear in the blood serum and the vaccinated person will be protected from infection,”the researcher explained.
However, it will not be possible to quickly introduce such a drug into practice, says Vitaly Zverev.
“I am a supporter of such methods and I believe that vaccination is the most reliable way to fight infectious diseases. But, first of all, you can't make a vaccine very quickly. It is necessary, at least, to be convinced of the safety of the agent that we introduce into the human body, and this takes a long time. Secondly, who will we vaccinate? It is unlikely that Covid-19 will become seasonal, like the flu. For this, the new virus, judging by the available data, does not mutate quickly enough. By the summer, the current epidemic will end - and that's it, we will forget about the coronavirus. This was the case with SARS in 2003. There was an outbreak, people were hurt. But nothing happened. There is still no vaccine for SARS-CoV, and this does not bother anyone. I believe that seasonal flu will kill more people during this period than the coronavirus. Because nobody canceled the flu epidemic,”the academician emphasized.
Authors: Alfiya Enikeeva, Tatiana Pichugina
