“Israel is providing the world with an extraordinary experience and the fact that it says that based on the very first results” with three doses of the anti-Covid vaccine “there could be protection” from the Omicron variant “is good news. It will have to be confirmed, but knowing the seriousness of the Israelis and how rigorous they are in giving data, I find it extremely reassuring “. Roberto Cauda, director of infectious diseases at the Gemelli Polyclinic in Rome, says this to Adnkronos Salute. “Israel is the laboratory of the world – remembers the infectious specialist – in the sense that it vaccinated the population before all the others in a very short period, it was the first to realize that immunity tended to decrease as we moved away from vaccination period especially against the infection and this led to vaccinating “with the third dose” first the over 60s and then everyone. And now he is also vaccinating children “. Regarding the Omicron variant, however, the preliminary data provided “are not surprising – the expert points out – because if you take the third dose it is possible that there may be an enhanced response that even if the Spike protein” of the variant “is not identical “to the Spike we are immunized against,” manages to block it. MIX VACCINES – On the advisability of changing the anti-Covid vaccine when taking the third dose, Cauda observes: “We went from saying ‘yes, heterologous vaccination can be done without any problem’ to saying that now it is better to be a heterologous one. To my knowledge there are still no studies with this type of RNA vaccine that tell us that one vaccination is better than the other “. “I made Pfizer Pfizer Pfizer – says the expert – There were studies, a Spanish one made on a few hundred cases, and a British one, on the use of the AstraZeneca adenovirus vaccine, followed or preceded by the Rna vaccine in which – recalls the infectious specialist – it was hypothesized that while the DNA vaccine could have a better impact in stimulating the cellular immunity response, the Rna one had more impact on humoral immunity. In this sense the two vaccines complemented each other. However – underlines the doctor – as regards a difference in advantage with the two RNA vaccines which are very similar to each other, although evidently not identical, at the moment it does not seem to me to have ever been reported. she can reiterate – she says – and it was what everyone said, it is: yes, you can be heterologous because after all nothing changes “. It has been said that for “vaccination with the Moderna vaccine there could be some effect a little more pronounced for a question of dosage. We have heard of everything and more, however – he reiterates – in reality they are quite interchangeable”.