Land new variants Omicron 4 and Omicron 5 have been officially defined in recent days “Variants of concern” (Voc) in the European Union. Precisely, on 12 May the European Center for Disease Prevention and Control Ecdc has reclassified these two sub-lineages of the Omicron variant of Sars-CoV-2, BA.4 and BA.5, from variants of interest to Voc. This is what the European body declared in the latest epidemiological update, and it cited Portugal as an example of the scenario that seems to arise. But what does it mean, what are the risks in Italy for the next few months? Can anyone who is vaccinated or has already had the infection get sick again? He talked about it to What’s the weather like last night May 15th Roberto Burioni, Full Professor of Microbiology and Virology, PhD in Microbiological Sciences and Specialist in Clinical Immunology and Allergology.
What are “variants of concern” or Vocs
According to the definition reported byTreccani Institute, “variants of concern” (Voc) means a “genetic mutation of a virus that is of concern due to its greater transmissibility than the original virus. Based on data updated to January 19, 2021, according to media and official sources, about 2,000 cases of the VOC variant 202012/01 (variant of concern, year 2020, month 12, variant 01, previously designated as VUI, variant under study) “.
Studies of the San Gerardo of Monza
As reported byPress Agency AdnKronos, BA.4 and BA.5 were first identified in South Africa, respectively in January and February 2022, and have since become the dominant variants in that area. The ECDC shows that both lineages contain specific mutations in the domain that binds the receptor of the Spike protein (Rbd) with respect to Omicron 2 (BA.2). Preliminary studies suggest a significant change in the antigenic properties of BA.4 and BA.5 compared to Omicron 1 and 2, especially compared to Omicron 1 ″. In Italy only a few weeks ago it was the new sub-variant of Omicron was isolated and genotyped at Microbiology laboratory ofSan Gerardo Hospital of Monzadirected by Doctor Annalisa Cavallero.
What are the variants
“Viral variants are modified viruses, which are formed due to the errors made by the virus, during replication. Sometimes, it happens that these errors give the mutated virus an advantage over the one that is circulating. This is the situation where we see a new viral variant coming. When the new viral variant has an advantage over the previous variant, it quickly takes its place, ”explains Professor Burioni.
Roberto Burioni during the program “Che Tempo Che Fa” (Photo by Stefania D’Alessandro / Getty Images)
Because they are more contagious
“There is, however, a crucial nuance, which must be understood: in a world of people who have never seen the virus or the vaccine, what is this advantage? The advantage lies in the greater contagiousness. In fact, as we have said several times, the variants Beta, Delta and, finally, Omicron 1, Omicron 2, they were all characterized by a greater contagiousness than the previous variant », Professor Burioni continues.
Can the variants reinfect those who have already had Covid?
“However, now the situation is different: many have had the vaccine, others have become infected, because the virus has become extremely contagious. Many, at this point, are immune, and the advantage for the virus, today, can no longer derive from greater transmissibility, but from being able to infect those who are immune againbecause he recovered or because he got vaccinated.
The situation, just in South Africaa, is very particular. There have been many cases of Covid, the total number was equal to 130% of the population. It means that almost all of them have been infected and even many have contracted the disease several times ».
What is happening in South Africa and why it affects us
So what is the advantage that the Omicron 4 and 5 variants seem to have in South Africa? «Not the ability to pass on better, but the ability to easily infect those who have recovered after contracting Covid, especially due to Omicron 1.
The numbers, which come to us from South Africa, are very preliminary, but it is striking that, for now, the number of cases is increasing dramatically, while hospitalizations increase much less, and deaths even remain stationary. Sure, these are preliminary data, but they could mean one thing – which, by the way, also happens in other infections, such as the flu. The virus, infecting immune people, causes a less severe syndromeown thanks to the immunity it encounters. A partial immunity, which fails to prevent infection, and therefore it does not block the circulation of the virus, but this immunity could still be able to make the disease less severe “explains Professor Burioni ..
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The protection given by the vaccine is superior
«In South Africa, the vaccinated are very few, 35% of the population. So, the most South Africans immunized with the infection and not the vaccine. Well, there are data that indicate that the the protection given by the vaccine against these variants is higher than that given by infection.
We must therefore ask ourselves what will happen when these new variants circulate in our country and collide with what we can rightly call the wall of immunity, made up of the large number of vaccinated people in our country, a very large number. greater than in South Africa.
In other words, there is hope – for now it is only a hope, but it is a reasonable hope – that the new variants are indeed capable of infecting vaccinated people, but, perhaps, causing less damage than the previous ones “.
Why keep getting vaccinated
«As we have said several times, it is not possible to predict the future, and we are unable to anticipate the moves of this virus. We are largely tired of him, but he is not tired of us. But perhaps we are forcing it to change in a direction that could be – fingers crossed – in our favor.
What we have to do, to increase our chances of victory against this particularly insidious enemy, is obvious: that wall of immunity, we must do everything to make it as solid as possible, because these new variants will sooner or later collide against this wall.
And how will we get this more solid wall? By vaccinating ourselves with three doses and hoping to have even more effective vaccines soon », concludes Professor Burioni.
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