The immunologist outlines the vaccination scenarios: «It is possible that the booster will ensure long-lasting immunity. In Europe, Omicron may not be so contagious “
What will there be after the third dose?
«In the meantime, let’s think about doing the third one, then we’ll see. At the moment we don’t know. There is no evidence that a fourth is needed. ‘
In the scientific world the debate is open but for Sergio Abrignani, immunologist of the scientific technical committee, it is premature to understand if we should really consider the one with the anti-Covid a fixed appointment.
Is the fourth dose a concrete prospect?
“It’s not the rule in vaccine history.”
Why do you usually need at least three doses?
“Most vaccinations against preventable infectious diseases involve two doses at close range and a third spaced, after 6-12 months. Just as it is happening for Covid 19. The first two serve to induce a strong immune response that acts immediately, the recall serves to strengthen the immune memory and make it lasting. We need a third injection not because the virus has managed to bypass the vaccine, but because there is a need to lengthen the memory of the immune system.
What is the experience of Israel, well advanced in the campaign of administering the recall, suggesting?
“The recall has been shown to restore the body’s response and correct the decline in memory. It was good news because it means that the delta variant does not escape vaccination ».
«The ideal for us humans would be to reach a lasting protection after the third dose, let’s say 5-10 years, a barrier against all the variants that might arise. The vaccines we now have have proven to be able to oppose three variants, the original one from Wuhan, the Alpha (so-called English) and the Delta (born in India) ».
What if the immune response continues to fade even after the booster?
“In this case we should consider a further dose, to be repeated every year, as for the flu which, however, presents itself with new viruses every year and forces us to change the vaccine”.
What do we know about the Omicron variant in relation to the vaccine?
«A variant, to become formidable, must have a competitive advantage, that is, it must be able to impose itself on circulating strains thanks to greater diffusivity above all. Even Omicron would appear, from South African data, to be more contagious. We do not know if this is related to the characteristics of the population of that area, since there is a high prevalence of immunosuppressed people. We have to see how it will behave in Europe. Will it have the same diffusivity? It’s not for sure”.
«Is it the cause of more serious forms of disease? Can he escape the vaccine and to what extent? Pending replies ».
Does the virus only change in the Spike protein?
«No, mutations also occur in other proteins but Spike is the one we care about as vaccines were built to counteract
used by the virus to attach itself to the human cell ».
If vaccines based on technologies other than those used to design the products of Pfizer, Moderna, Astrazeneca and Johnson & Johnson arrive, could we have better results not having to keep up with the number of doses?
“It is unlikely, technologies can change but the protection mechanisms on which we must act are always the same”.
The arrival of specific antivirals against Sars-CoV-2 has been announced.
«The golden rule applies. Prevention is better than cure. Species this disease that even after recovery can give rise to pathological consequences, after months “.
How do you read the epidemic situation in Italy?
«The curve rises, but more slowly. And this is thanks to the high rate of vaccinations, the rules maintained, the green pass. The difference has been seen and it is not a coincidence if the rest of Europe suffers the wave while we are managing to contain it ».
December 5, 2021 (change December 5, 2021 | 07:07)
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