“The fourth dose” of the Covid vaccine “they are proposing is still on the original Wuhan virus strain, but that protein has not existed for a year and a half.” Thus to Adnkronos Salute Massimo Ciccozzi, head of the Medical Statistics and Epidemiology unit of the Faculty of Medicine and Surgery of the Bio-Medico Campus of Rome, comments on the possibility of doing the fourth dose, which some European countries are offering to the most vulnerable citizens. . “It is true that thank goodness the data tell us – emphasizes Ciccozzi – that with three doses that vaccine still works, but I am opposed to having a vaccine every 4 months because – says the expert – the immune system is stressed, too. The basic immunologist knows. Why do I have to do this? Unless you offer me an up-to-date vaccine on the Omicron and Delta variants. ” “I’d wait a while” to handle the Covid-19 pandemic as an endemic. “Spain does it, England does it, but I am much more cautious, optimistic but cautious. Let’s see the data from the middle of next week: if they start to contract we can also start thinking, but for the moment I would say no. “, he adds, commenting on a possible breakthrough in the management of the emergency. However, he points out,” people are wrong to say that Omicron is like a flu: they are two different viruses, the flu and the Covid virus. This is a coronavirus which over time will become a human coronavirus and give the symptomatology of a human coronavirus, the flu is another virus “.