In the next few days, on behalf of the President, vaccination against coronavirus should begin in all regions of Russia. The Sputnik V vaccine will be given to Russians at risk – doctors, teachers and those who are in contact with a large number of people at work. What you need to know about vaccination, can a coronavirus mutation affect vaccination, who are the most dangerous carriers and how dangerous asymptomatic carriers can be – “Lente.ru” told Alexander Gorelov, Academician, Deputy Director for Research, Central Research Institute of Epidemiology Rospotrebnadzor.
–
“Lenta.ru”: Vaccination begins in Russia. Should people be afraid of the side effects of a drug that has just appeared?
Gorelov: All vaccine preparations once appeared for the first time, and now they have a long history. But at the same time, the main thing must be said: any vaccine preparation, in whatever country it is developed, passes the obligatory stages of clinical trials. There are four of them, as you know. And it is clear that no one allows himself to deviate from the international protocol, because the key point – in addition to efficiency, must be security.
We protect healthy people, so special vaccine requirements are strictly enforced. There is an international inspection for all protocols. And only after all the necessary phases have been completed, the official state registration of the drug is carried out. And in each subsequent country where the drug is registered, appropriate post-registration tests can be carried out, but this is an optional step. Therefore, there are also correspondences between many countries – registration in one country is counted in another. But the protocol is spelled out, it is absolutely unshakable and there are no exceptions to it.
Any side effects that may appear after vaccination are within the scope. Except in rare cases when there may be an individual reaction to the drug. Therefore, before the introduction of the drug, thermometry, examination and conversation with the doctor are required. And after the introduction of the drug – regardless of whether it is new or old – for at least 30 minutes a person is in a medical institution under medical supervision. This is a general and well-tried rule that applies all over the world. It requires certification of the vaccination office. There is a checklist that is required in order to obtain a vaccination license. And there is a mandatory set of procedures that will minimize the occurrence of adverse reactions.
You said that there is no absolute protection against coronavirus. Can people get infected after vaccination? How will the disease proceed?
Potentially, the body can meet the virus, but a severe course will not develop and there will be no complications.
According to you, the likelihood of re-contracting the coronavirus is minimal in any case due to virus mutations that affect only one percent of the genome. Could this situation change? Is there a chance that there will be some kind of mutation that negates the effect of the vaccine?
The fact is that mutations are characteristic of the RNA virus. But the key point is not the presence of mutation, but its consolidation, transmission to descendants. It is clear that the whole world is monitoring the mutations of the virus genome, and at the moment there are about 160 thousand complete sequenced genomes of the virus, placed in the genebank and identified in different parts of the world. But no significant mutations were noted.
The virus is adapting, it needs to gain a foothold in the human population. This is why this happens frequently in rapidly mutating viruses (such as influenza viruses). Therefore, the circulation of their strains is monitored, and the vaccine composition changes in accordance with the changes. But this is only with influenza viruses, because they mutate quickly. That is why there are 58 points in Russia to monitor the circulation of various influenza viruses. All information is collected in two centers, which transmit the data to the WHO European Influenza Office. Since this is a seasonal disease, the area of its distribution, depending on the season, moves from the Northern Hemisphere to the Southern. Thus, we always know when in the Northern or Southern Hemisphere the season of the rise in the incidence of respiratory infections and influenza has ended.
In the case of coronavirus, there are currently no significant mutations that would require a change in vaccine drug
–
Moreover, in Russia 43 candidate drugs are being developed not only against the virus itself, but also against its gene regions or individual significant genes, for example, a spike protein to which the virus attaches. Different approaches are used to develop vaccines: vector vaccine, attenuated vaccine, peptide vaccine. And you can’t judge each of these drugs in the same way. It is our happiness that there are many vaccines, doctors will have a choice of which drug to vaccinate, and, most importantly, we will be able to respond to the challenges that will arise.
The key is to develop a matrix of vaccines, which, as with influenza vaccines, can change. The most important thing: the vaccine is ready, production is being scaled up, the technology is there, and it will be possible to change it, if necessary, thanks to the matrix. In it, the components can change. And this is not our immediate prospect. Fortunately, the virus has not significantly mutated in ten months. But if there is any significant mutation, in this matrix they will simply change or add components that will be associated with the new mutation in order for the vaccine preparation to work.
Is it true that children have become more infectious? Is this a mutation of the virus?
It is not entirely correct to say that children are the main source of infection. It is a drip infection, and the drops do not fall up, but down. Therefore, most often children get an infection from adults: when they cough, sneeze and talk, drops fly down. Two thirds of children are infected at home.
The first case of the child’s illness was described back in March. This child was 36 hours old. He got infected from his mother
–
But most often adolescents or children from the age of seven were sick. But the share of children in the total morbidity structure for nine months did not exceed 8 percent. That is, 92 percent were adults. Children have a different immune system, they react differently to the virus. Therefore, children get sick, but less often than adults.
There were publications that children shed RNA viruses with feces, but no one proved that this is a viable virus, and not its fragments. As knowledge accumulates, it is this parameter that is important to us – the infectious ability of the virus, that is, such a concentration at which the disease develops. As for the virus isolation period, it is the same for everyone. With a mild form, the infectious period is 10 plus or minus two days, with a moderate form – 20 plus or minus two days. And the infectious period begins at the end of the incubation period, that is, a day or two before the onset of symptoms. In adults, discharge is described both after 48 and after 90 days, but these are isolated cases.
The key points during infection are the timing and density of contact. If contact with an infected person occurs indoors for more than 15 minutes, then the risk increases – it does not matter if it is a child or an adult.
Moreover, half of the children are asymptomatic. This suggests that children and the virus shed less. It takes about a thousand viral particles for an adult to fall ill. When talking or breathing, usually no more than two hundred are released. Therefore, a cough or sneeze is needed – symptoms that children usually do not have.
Why do some people become super-distributors? Who are the main super-distributors in Russia?
All people have different immune systems, we react differently, and the dose for infection is completely different. The first super-spreader of the coronavirus was in South Korea. There, a woman came to church and infected 1,200 people. It was possible to trace this on mobile phones. And such situations occur periodically. People like this woman are considered super-distributors. These are people who spread the virus in closed rooms with poor air circulation, where there is no decontamination, where social distance is not observed and where no one is wearing personal protective equipment. Public transport is a classic example.
And it’s not about any peculiarities of a person. This is the result of non-compliance with the basic rule: sick – stay at home.
If a person has a severe form, he coughs constantly, then the likelihood of infection from him increases.
–
But in closed rooms with prolonged contact, it is easy to get infected from an asymptomatic one, which means that under certain conditions such a person can become a super-distributor. Indeed, in the same Sweden there is no such population density, and they chose five meters as a social distance.
It all depends on the conditions. It’s one thing when an asymptomatic carrier goes out into the yard of his farm in the village, when the nearest house is 30-50 meters away. The other is when he enters the entrance of a multi-storey building and rides in an elevator in a confined space. This is a completely different situation. The key point is the social activity of the individual.
And how will a person feel when reinfected with coronavirus?
There are now about 30 documented re-infections worldwide. And, for example, one of them was fatal. It was a woman in her nineties in Holland who suffered from hematological cancer.
Most often, as practice shows, the recurrence of the disease is more severe. Why this happens is difficult to explain. This is due to the individual reactivity of the organism. Re-infection is possible only when there is some kind of defectiveness of the immune response, when the body cannot cope and does not produce enough antibodies.
But with the vaccination, the immunity will be trained, and, meeting with this virus, it will not allow the infectious process to roam until the cytokine storm. If a person is vaccinated, he does not face serious complications, resuscitation and mechanical ventilation.
How will the vaccine work on asymptomatic carriers of covid? Suppose a person does not know that he is infected, or the symptoms have not yet appeared, what will happen?
There is absolutely no need to be afraid. We know that there is a booster effect, that is, an increase in immunity. Because most often, asymptomatic carriers have a not very intense immune response after an infection, so vaccination seems to boost. And if the virus does not mutate (we are counting on this), when it encounters a virus, the immune system will already recognize it, and the antibody titer will increase. Two doses of the vaccine are needed to develop primary protection. And all subsequent meetings will train immunity and maintain a protective titer at the immune level.
Therefore, the asymptomatic form is not a contraindication, which cannot be said about the mild or initial form. The presence of any symptoms of acute respiratory illness is a contraindication. Why do you need a doctor’s examination?
If a patient has a red throat and a stuffy nose, no one will vaccinate him. No doctor will take such responsibility
–
And if a person is asymptomatic, it means that the immune system has already reacted in such a way that the process has not developed.
Everyone says the pandemic will end with herd immunity and mass vaccinations. Is it necessary to vaccinate the entire population? Or will some part be enough?
In risk groups, about 70-75 percent of people should be vaccinated. We are not talking about elimination – so that there is no virus at all, as is the case with measles. There, vaccination coverage should be about 90-95 percent.
The analogy is best drawn with influenza, and we know perfectly well that the epidemic slows down when it is the risk groups that have that coverage. The coronavirus is not as contagious as, for example, the same measles. And an infected person infects fewer people than if they had measles. For a virus to become seasonal, like the flu, it is enough to reduce its circulation. And vaccination just allows you to achieve this effect.
–
