What we know about Omicron: answers to main questions
Why we are all very likely to get infected with Omicron, how the coronavirus has managed to change so much, whether vaccinations will save us from the new strain and what awaits us
What news about the Omicron strain of coronavirus makes officials faint, why a significant part of antibodies to previous COVID-19 variants may simply be useless, what truth is being kept silent at Pfizer, whether coronavirus vaccination remains effective Irina Yakutenko, a well-known molecular biologist and scientific journalist, told about this and many other things during her recent stream “Omicron avoids antibodies after vaccination and illness. Is this the end or not yet?". Realnoe Vremya about main points from her story.
- When and where did Omicron appear?
On November 24, South Africa officially announced that the new strain of coronavirus was discovered in the country, which later received the name “Omicron”. And already on November 26, the WHO convened an extraordinary meeting on this occasion. The organisation has officially classified the mutated virus as a variant of concern (VOC).
- How is Omicron dangerous?
It contains many mutations that appeared simultaneously. The previous strains differed from each other, but there were few differences. In the case of Omicron, scientists immediately saw 50 significant substitutions in the genetic code that lead to changes in the protein component. It was from this that scientists and health officials began to faint. More than 30 significant substitutions in the spike protein (coronavirus spike) means that its shape will be changed very much. After all, a protein molecule is like a ball of wool rolled up randomly. If one amino acid changes, it can change the shape of the protein in a completely different place. And if several amino acids change, they can change the shape of the protein in a difficult predictable way. It is very difficult to predict what a protein will look like when so many amino acids have been changed in it.
Antibodies may simply stop recognising the spike protein because they were developed for previous variants of the coronavirus, in which this protein had a completely different form. Imagine that the antibodies are given a completely new one that looks absolutely wrong. It can be assumed that a significant part of the antibodies that recognised certain pieces of the surface of the old spike protein will simply become useless. This was the first assumption of experts, which could only be verified experimentally.
- How could so many mutations appear at once?
The main assumption is the result of the long evolution of the virus in the human body with immunodeficiency. In such a patient, the immune system cannot kill the coronavirus, which has been multiplying for months. On the other hand, his immune system is weak, but it attacks. As a result, the weakest, unadapted viruses die, only those that can somehow escape from antibodies survive. As a result, this person infected someone, and “all this” began to multiply.
- Are there any experiments already? Is this strain really eluding antibodies?
Experiments to neutralise the virus in the laboratory are carried out as follows: it is multiplied in cells, and then the serum of those who have been infected or vaccinated is poured on these cells. The serum contains antibodies. If they are active, then the serum should prevent infection of the cells. It is enough that at least 50-90 percent of the cells are not infected. If the serum is not effective— it will not prevent infection of cells. The more effective the serum is, the more times it can be diluted, and at the same time, it will still prevent infection. Dilutions occur thousands of times.
The first results came from an African laboratory (Alex Segal from the African Institute of Health Sciences in South Africa). Scientists have seen a drop in neutralisation efficiency by about 40 times. It's very much. For the previous variants, in particular the Delta, the drop was only eight times. This suggests that Omicron is very sharply moving away from the antibodies in the test tube.
- So, are vaccines ineffective against Omicron?
Do all these results mean that vaccines don't work? No, it does not. The decrease in the effectiveness of neutralisation is not equal to the decrease in the effectiveness of the vaccine. It may fall, but a 40-fold drop in neutralisation does not mean that the effectiveness of the vaccine has fallen by 40 times.
The vaccine gives us more sophisticated protection than antibody protection. We have two areas of protection. The first is antibodies that prevent the virus from infecting new cells. The second is T-cells, the “killers” that destroy cells infected with the virus. If the immune system understands or suspects that a cell is infected with a virus, it kills it without talking.
Vaccination, like the disease, stimulates the formation of T cells. According to preliminary estimates, T-cells developed against previous variants of the coronavirus will retain good activity against Omicron. T-cell immunity is a little more reliable. T cells are responsible for the fact that if you get infected, you will not need to go to the hospital and you will not die. Data on all vaccines show that the effectiveness in terms of protection against severe course of all vaccines remains very high. The T-cell immunity of those who have been infected and vaccinated is well formed, so from this point of view, everything is more or less normal.
However, we are all likely to get infected with this strain of coronavirus, because data from South Africa on the number of repeated infections after vaccination or illness show that with the appearance of Omicron, the number of breakthrough infections has at least doubled. The first bastion — antibodies —works very poorly against Omicron. Therefore, symptoms may appear, you may get sick.
But as we hope, T-cell immunity should protect against a severe course. Indirectly, we see this from research, but it's too early to say for sure — it takes time. If the number of people on ventilators and dying does not significantly increase in the next 2-3 weeks, this will indicate that the second bastion — T cells — remains reliable. Perhaps, the mild course of Omicron, which we observe, is due to this — to the presence of T-cells in infected people (who have been ill or vaccinated).
But if you haven't been vaccinated and haven't been infected yet — you don't have T-cell immunity!
- How does the disease caused by Omicron proceed in the unvaccinated?
In Africa, most likely, all those infected with the Omicron strain have had coronavirus before or have been vaccinated. In the UK, where community immunity has already been practically formed, we mostly see patients who have already received antibodies in one way or another.
It is interesting to see how the disease caused by Omicron will proceed in non-immunised patients. But so far, a statistically reliable array of data has not accumulated.
- Is Omicron dangerous for children?
In the African data on hospitalisation, we see a bias towards children. There is an unusually high percentage of young children in hospitals — most likely, these are the very patients who do not yet have immunity. So far, there are no children's deaths. But there is already a small alarm bell.
- What is the rate of Omicron infection?
The virus spreads very quickly wherever it gets. In South Africa, the growth lines of new cases go up sharply. What is most unpleasant is that the curve of not only positive tests goes up sharply, but also the proportion of positive tests among all the tests performed. This suggests that we simply “don't catch” a lot of infected patients, which means that a lot of contacts are missed.
We have returned to the beginning of the pandemic — to the exponent, which was shot down by vaccination and quarantine. In South African Gauteng, we see a very high rate of spread. And in England, the speed is similar. It is possible that with the current dynamics, Omicron will most likely overtake Delta by Christmas.
But is it as contagious as Delta? We don't know. For Delta, the vaccinated were a dead end. It could also infect them, but with a much lower probability than unvaccinated ones. It worked in the opposite direction as well: vaccinated people were much less likely to infect others. But in the case of Omicron, this is not the case. For him, vaccinated, especially without a booster dose, are easy prey. Not in the sense that they will die — but that he will jump over them, begin to multiply and will spread further. It can be assumed that Omicron, if it gets into any population, will begin to spread rapidly.
- What are the forecasts? Is everything bad?
Omicron will begin to adapt to the new conditions. How it will do it, no one can predict yet. With a high probability, the coronavirus will continue to mow down those whom it has not yet mowed down. We have saved a huge number of lives thanks to vaccination.
But if we have a strain that affectes the vaccinated, it can finish off those who have not been infected with Delta. It is possible that many patients with chronic diseases, obesity and other aggravating diseases of the Omicron strain will not survive. So the rapid spread of Omicron should not be allowed.
Yes, this strain demonstrates a significant rate of antibody avoiding. There is a high probability of an increase in the frequency of repeated infections. Omicron easily infects vaccinated people. But vaccination plus the previous disease protects quite well. Perhaps, the protection of vaccination against severe course is preserved. Omicron is definitely not heavier than Delta — at least for those vaccinated and infected. Therefore, it is important not to panic.
In addition, it is necessary to get “boosted”. Especially if you have done two doses of vaccination for a long time. “Booster” certainly provides additional protection. It makes sense.
But in order to prevent infection with Omicron as much as possible, new vaccines will be required. Moderna and Pfizer have already started work, Sputnik is also technically easily converted to the new strain. But the upgrade will take about 3 months. The first batches of the new vaccine may begin to be delivered in March 2022.