The fourth dose of the Covid vaccine: who should do it now and why there is no point in waiting for the fall

Partly because there is a desire to take time off even from Covid subjects, partly because it is believed that it is better to wait until autumn, and the fact is that the fourth doses of the Covid vaccine are not many even among the more than eighty-year-olds and immunocompromised, to whom the drug is intended Second. According to the latest data, only 28.8% have been vaccinated, and given that we are now in the month of July, it is expected that this percentage will not increase by much.

But in the meantime, cases are increasing and some doubts begin about the advisability of following the recommendations of the Ministry of Health: who can not wait until autumn? What is the duration of the effect of the fourth dose? Isn’t it better to wait for updated vaccines? The professor answers these and other questions Fabrizio Brigliascoa virologist at Milan State University and medical director of the Irccs Galeazzi Foundation.

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Who should take the fourth dose now

As defined in the circular issued by the Ministry of Health, the fourth dose is recommended for people over 80 or 80 years of age, for RSA (hospital care assisted) guests and for those included in risk categories between 60 and 79 years of age. Is it a matter of age or weakness? “From both things – Pregliasco’s responses -. First of all, now fragile people should take the fourth dose, without waiting any longer, but they are pretty much older because after the age of 80 they have multiple comorbidities, which they are and that’s why they have to protect themselves more.”

Vaccine for immunocompromised

In particular, the ministry memorandum, Iss (Higher Health Institute) and Aifa (Medication Agency), stresses that “the highest priority remains to vaccinate those who have not yet received the third dose and to give the fourth to those with markedly impaired immune response associated with disease. chronic or pharmacological treatments and people undergoing organ transplantation.” For them, it makes no sense to wait for the fall: “It is a pity – emphasizes Brigliasco – not to take the opportunity to take advantage of their right to take the fourth dose at this very moment when the virus accelerates again.”

Masks are like sunglasses

On the other hand, who can wait for fall to get vaccinated again? “All those who do not fall into these categories and who, however, should continue to use common sense by wearing, for example, masks as in summer with sunglasses, that is, in cases where they are needed, especially Inside,” Pregliasco explains.

But among doctors there is a hypothesis of lowering the minimum age in order to reach the fourth dose: “I would not rule out the opportunity to expand beyond the 50s either. I think that the Covid vaccine in the future should become like the flu vaccine, this is annual and accessible even before the age of Sixty,” explains the virologist.

How should the injured

Of those frail and over 80, who received their first booster dose, then a three-dose course and then developed a normal infection, can they skip the fourth dose? “If he has been ill recently, yes – answers Pregliasco – because the infection has given him a kind of booster of immunity acquired from the vaccine, but if it has been four months since he recovered from the disease, it is better to take an IV dose because protection against disease and recovery decreases over time and in light of these variables It is necessary to strengthen memory T cells to increase defenses.”

And on the other hand, he developed unexpected and unconscious symptoms with Omicron 5 risking a fourth dose? “Absolutely not, there is no risk and you can get the vaccination with complete peace of mind,” the expert reassures.

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What are the vaccines for the fourth dose?

What type of vaccine is the fourth dose given? “Currently – explains the virologist – the Pfizer and Moderna vaccines, which are based on messenger RNA technology, have been approved for the fourth dose, but this is only because there is still no evaluation of efficacy and therefore approval for use as the fourth dose. Other vaccines are available.”

The fourth dose and the feasts

Another very frequent doubt concerns when to make the fourth dose: It’s summer and for many families the holidays will start soon, perhaps with the grandparents around. Isn’t it too late now? “Not at all – answers the virologist, who urges -. The fourth dose increases antibodies rapidly: after 8 days it is already at its maximum. It is estimated that the wave will peak between July 15-30 with 150 thousand cases. But then it will take It’s all August to go down. And two months is the protection provided by the fourth dose. The virus continues to spread: we are in a transitional phase between the epidemic and the endemic trend. Right now there is an undulating trend, like circles that are formed by throwing a stone into a pond.”

New updated vaccines

But the vaccines available today are based on the original Wuhan virus (2020) and at the same time new variants are being circulated. Many people wonder why they should be immunized with the fourth dose of an old vaccine. When asked, Brigliasco replied: “The story of the old and ineffective vaccine is wrong because it activates cellular immunity, and at this point it is necessary to reactivate this response while waiting for the cyclic recall.” He added: “We should not consider the vaccines that we have now useless because, in any case, they increase the immune response and continue to protect against serious diseases and deaths, which are the primary goals.”

How long does the fourth dose protect?

How long does immunity last for the third dose and when is the fourth dose taken? “The third dose – notes the virologist – lasts 4 months, however, there is a decrease in protection and then stability. Therefore, the remaining protection remains, but for the weak it is especially important to do the fourth dose. It has been four months since the last booster dose, as That protection from the fourth dose has the same duration. Who takes the fourth dose today, what should they do in the fall? In my opinion, after four months they will have to do the new updated vaccine, but it has not yet been determined. “

Blood test before the fourth dose

Some doctors advise patients to have tests before the fourth dose to check if there is an ongoing infection: are they helpful? “It is useless – points out the virologist. It is completely useless, but sometimes you are afraid of negative events and possible side effects, even if there is no element that justifies them. You do not even need a serological test. Because your presence does not necessarily mean antibodies Protection from infection. Over time, these antibodies decrease, and for a possible confrontation with the virus, they are not enough to avoid infection.”

Another widespread doubt: Could the fourth dose have more severe side effects, knowing that it is added to other previously administered vaccines? “Absolutely not, there is no cumulative effect,” Brigliasco explains.

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A more voluntary virus?

If the fourth dose is taken earlier, can this summer wave be avoided, or at least reduced, or not because vaccines are not specified? “Surely the fourth dose would have helped reduce infection, but above all to reduce severe effects and deaths among the vulnerable – as Brigliasco explains – and the different proportion between the number of new infections and serious cases is associated with two effects: first the virus has subsided, but it is also true that It stumbles on people who have already recovered. In fact, 9% of daily cases are of people who have returned to infection. We can say that our body is like Ukraine, that is, it manages to fight the invasion of the virus. Moreover, it encounters people who have residual protection that does not prevent the virus from infecting them. But they can respond.

Updated Vaccines

Finally, many believe it is best to wait for new updated vaccines, but since they were developed with the now-disappeared Omicron 1 and because new mutations are constantly ‘seen’, waiting is not said to actually be beneficial. Among other things, even if we can get a vaccine against BA.5 within a few months, we are not sure that this sub-alternative will still prevail by then.

In short, isn’t it a poor strategy to keep track of the virus and its variants? “All vaccine updates increase the ability to protect – confirms the medical director at Galiazzi – and it’s the same thing that happens with the flu vaccine that changes every year.”

But since the virus is constantly changing, wouldn’t it make sense to develop a universal coronavirus vaccine? “We are working in this direction, but it takes time – concludes Brigliasco -. The results are interesting, and the problem is that it is not easy to find the antigens to focus on.”

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