Partly because there is a desire to take a vacation even from Covid themes, partly because it is thought it is better to wait until autumn, the fact is that the fourth doses of the anti-Covid vaccine are not many even among the over eighty-year-olds. and the immunocompromised, to whom the second booster is dedicated. According to the latest data, only 28.8% have been vaccinated and given that we are now in July it is to be expected that this percentage will not increase by much.
But in the meantime the cases are increasing and some doubts about the advisability of following the recommendations of the Ministry of Health begin to circulate: who cannot wait for the autumn? How long does the effect of the fourth dose last? Isn’t it better to wait for the updated vaccines? Professor answers these and other questions Fabrizio Pregliascovirologist of the State University of Milan and medical director of Irccs Galeazzi.
Covid, with the fourth dose, infections reduced by four times in a month
by Viola Rita
Who should take the fourth dose now
According to what has been established by a circular from the Ministry of Health, the fourth dose is recommended for people over or at the age of 80, for guests of RSA (assisted healthcare residences) and for those who have been included in the risk categories with an age between 60 and 79 years. So, is it a question of age or frailty? “Of both things – replies Pregliasco -. First of all, now the fragile subjects have to take the fourth dose, without waiting any longer, but they are largely elderly because after the age of 80 they suffer from multiple concomitant pathologies, and it is precisely that’s why they have to protect themselves more “.
Vaccine for immunocompromised individuals
In particular, the ministry note, Iss (Higher Health Institute) and Aifa (Medicines Agency), underlines that “the highest priority remains that of vaccinating those who have not yet received the third dose and of administering the fourth to those subjects with marked impairment of the immune response linked to chronic diseases or pharmacological treatments and to subjects undergoing organ transplantation “. For them it makes no sense to wait for the autumn: “It is a pity – underlines Pregliasco – not to take the opportunity to take advantage of their right to take the fourth dose at this very moment when the virus is accelerating again”.
Masks such as sunglasses
Who, on the other hand, can wait for autumn to get vaccinated again? “All those who do not fall into these categories who, however, must continue to use common sense by wearing, for example, masks as is done in the summer with sunglasses, that is, in situations where they are needed, especially indoors” , explains Pregliasco.
But among doctors there is the hypothesis of lowering the age threshold in order to access the fourth dose: “I would not rule out the opportunity to extend to the over 50s too. I believe that Covid vaccination in the future should become like flu vaccination, that is annual and with access even before the age of 60 “, clarifies the virologist.
How should those who become infected
Among frail subjects and over 80, who received the first booster dose, then a three-dose course and subsequently contracted the natural infection, can skip the fourth dose? “If he has recently become ill, yes – replies Pregliasco – as the infection has given him a sort of strengthening of the immunity acquired with the vaccine, but if four months have passed since the disease had cured, it is better to take the fourth dose because the protection of disease and healing decreases over time and in the light of these new variants it is necessary to strengthen the memory T cells to increase defenses “.
And who, on the other hand, has asymptomatically and unconsciously infected with Omicron 5 runs risks by undergoing a fourth dose? “Absolutely not, there is no risk and you can get vaccinated in complete peace of mind”, reassures the expert.
Long Covid affects almost three times more people who are not vaccinated with the third dose
by Donatella Zorzetto
What vaccines for the fourth dose
What type of vaccine is the fourth dose given? “Currently – explains the virologist – Pfizer and Moderna vaccines, both based on messenger RNA technology, have been authorized for the fourth dose, but this is only because there is still no evaluation of efficacy and therefore approval for use as a fourth. dose of other available vaccines “.
Fourth dose and holidays
Another very frequent doubt concerns the right time to make the fourth dose: it is summer and for many families the holidays will soon begin, perhaps with grandparents in tow. Isn’t it too late now? “Absolutely not – replies the virologist, who urges -. The fourth dose increases the antibodies rapidly: after 8 days they are already at their maximum. It is estimated that the wave will peak between 15 and 30 July with 150 thousand cases . But then it will take all of August to go down. And two months is the protection offered by the fourth dose. The virus continues to circulate: we are in a transition phase between the epidemic and the endemic trend. At the moment there is an undulating trend, like the circles that are formed by throwing a stone into a pond “.
The new updated vaccines
But the vaccines available today are based on the Wuhan native virus (2020) and in the meantime new variants have been circulating. So many people wonder what reason there is to get immunized with the fourth dose of an old vaccine. When asked, Pregliasco replies: “The story of the old and ineffective vaccine is wrong because it activates cellular immunity, and at this stage it is essential to reactivate this response while waiting for the periodic recall”. Adding: “We must not consider the vaccines that we now have useless because in any case they raise the immune response and continue to protect against serious illness and mortality which are the two fundamental objectives”.
How long does the fourth dose protect
How long does immunity last for the third dose and when to do the fourth? “The third dose – notes the virologist – lasts 4 months, during which, however, there is a decrease in protection and then a stabilization. Therefore, residual protection remains, but for the frail it is especially important to do the fourth dose. if four months have passed since the last booster. The protection of the fourth dose also has the same duration. Who takes the fourth dose today, what should they do in the autumn? In my opinion, after four months they will have to do the new updated vaccine, but it is Still to be defined”.
Blood test before the fourth dose
Some doctors advise patients to do tests before the fourth dose to check if there is an ongoing infection: is it helpful? “It is useless – the virologist points out -. It is completely useless, but sometimes you are afraid of possible adverse events and side effects, even if there is no element that justifies it. You do not even need a serological test. because having antibodies does not necessarily mean being protected from infection. Over time these decrease and for a possible encounter with the virus they are not sufficient to avoid infection “.
Another widespread doubt: could the fourth dose have heavier side effects, given that it is added to the other vaccines carried out previously? “Absolutely not, there is no accumulation effect”, explains Pregliasco.
Covid, ‘old’ and updated vaccines: how much we are protected from the new sub-variants
by Irma D’Aria
A more docile virus?
If the fourth dose had been taken earlier, could this summer wave have been avoided, or at least limited, or not because vaccines are not specific? “Certainly the fourth dose would have helped to reduce infections, but above all to reduce heavy effects and mortality among the frail – explains Pregliasco -. The different proportionality between the number of new infections and serious cases is linked to two effects: on the one hand the virus has calmed down, but it is also true that it stumbles upon people who have already recovered. In fact, 9% of daily cases are of people who reinfect. We could say that our organism is like Ukraine, that is, it manages to dab the invasion of the virus. Furthermore, it encounters people who have residual protection that does not prevent the virus from infecting them, but who manage to react “.
The updated vaccines
Finally, many are convinced that it is better to wait for the new updated vaccines, but since they were developed with Omicron 1 which has now disappeared and because new mutations are constantly being ‘sighted’, it is not said that the wait is actually useful. Among other things, even if we manage to obtain a vaccine against BA.5 in a few months, we are not sure that by then this sub-variant will still be the prevalent one.
In short, isn’t it a weak strategy to pursue the virus and its variants? “All vaccine updates increase the protection capacity – assures the medical director of Galeazzi -. It is the same thing that happens with the flu vaccine that changes every year”.
But since the virus is constantly changing, wouldn’t it make more sense to develop a pan-coronavirus vaccine? “We are working in this direction, but it takes time – concludes Pregliasco -. The results are interesting, the problem is that it is not easy to find the antigens to focus on”.