The vaccination schedule to receive the fourth dose against covid-19 will admit starting this Tuesday all people over 18 years of age who want to be vaccinated. From February to date, the qualification only applied to the group over 50, although the public recommendations pointed from the beginning to people with comorbidities.
On the day of the announcement, the Ministry of Public Health published a list in which it detailed a series of pathological complications that affect the immune system and clarified that the inoculation was aimed especially at people with previous illnesses.
Likewise, when announcing the expansion for people between 18 and 49 years of age, the Minister of Public Health, Daniel Salinas, once again referred to risk groups: “From the MSP there is no access to electronic medical records individually as to form differentiated cohorts. The phrase of the president of responsible freedom here is responsible responsibility and we appeal to each one to know whether or not they have comorbidities and if it is within the parameters to give it to them, “he declared.
But, then, how recommendable is the fourth dose for a young and healthy person and why did the MSP decide to open the agenda for these groups as well?
“It’s better to prevent than to cure”
Expert opinion is dissenting on this point. In the first place, because, as Salinas said, the portfolio will not be in charge of controlling whether or not those who receive the dose register comorbidities and, secondly, because there are not too many approved alternatives in the world to combat the evolution of covid-19.
In what the specialists consulted by The Observer is that although the drug is not contraindicated, it is possible that its benefits vary depending on the groups.
The director of Pereira Rossell and pediatric infectologist Álvaro Galiana, for example, is aware that “there is still no other option” approved to strengthen neutralizing antibodies against the virus, so he believes it is “very important” to advise the vaccine.
Whether it is for the elderly or young people, he assured that receiving it “changes”, firstly to counteract the drop in antibodies and secondly to maintain the decrease in serious cases, ICU admissions and deaths. With the letters available to the ministry, Galiana insisted that, for the moment, “prevention is better than cure”: “For now that is the law and it is the objective. We will see later if the option of new vaccine variants, probably keeping the same messenger RNA system.
In turn, he said that “the important thing” is that laboratories focus on epidemiological surveillance, since covid-19 maintains a similar behavior throughout the world. “This is like playing chess: I make a new move and it can go wrong. What has been scientifically proven so far is that, especially in older people or people with comorbidities, the fourth dose is very important. The difference between two, three or four doses is what later makes the difference in the people who enter the CTI, not that you get sick or infected. It is essentially that you get complicated later and that you have a more serious infection, “he summarized .
The director explained that one of the current debates raised by the scientific community refers to a possible adequacy of immunization, as is the case with the flu. “Today the question is whether the same thing is going to happen with the flu. With the flu, evaluations are being made annually in the northern and southern hemispheres to see which variant predominates and to adapt the immunization for the possible circulation of the flu. next season. With the covid you have to know in what time it changes from one variant to another”. he insisted he.
For his part, Juan Cristina, virologist and former dean of the Faculty of Sciences, defended the recommendation to enable a fourth dose in the face of an increase in weekly cases in the last two weeks and indicated that, so far, the MSP is rehearsing the “move” you have at your fingertips.
In his opinion, the injection “moves the needle” when the numbers of serious cases are analyzed, although the current scenario in the country already has “a population that generally has three doses and a huge number of people recovered from the infection, who for a while has immunity”.
But as the virus mutates, “the higher you have neutralizing antibodies, the better.” This is how he explained it: “I think it is well advised. There is a feeling that the pandemic is over and of course not. Now there is an increase in cases that, although it is not to give a public alarm, is one of those things that you have to get used to,” he assured.
When vaccinated, the Uruguayan population generates a “great suppression of the viral population” and flattens it as much as possible, the expert stressed. “When you go to the CTI, non-immunized people predominate. With significant comorbidities or few doses,” he added.
Cristina called on the laboratories to remain alert to epidemiological surveillance while pointing out that, sooner or later, all variations of the virus will reach the country. “The predominant variant must be detected as quickly as possible and paid attention to. For now what you have is to try to keep the levels of antibodies as high as possible in your people. Later, we will see. There are more than 100 candidate vaccines that are being developed. testing right now,” he said.
Time to redirect strategy?
Speaking to El País, virologist Santiago Mirazo disagreed with his colleagues by pointing out that the fourth dose “does not increase immunity substantially with respect to the third dose”, so it perhaps made “more sense” to think of a vaccine “adapted to new variants” before issuing the aforementioned recommendation.
This Monday, consulted by The Observerthe specialist resolved the differences and clarified that the fourth dose favors people at risk to avoid serious cases and that, in turn, it is not “contraindicated” for other groups.
However, in his opinion, the seriousness of the disease had already been resolved with the approval of the fourth dose. “It’s not that a fourth dose is going to do you any harm, (…) you have to think that we already have good protection against serious cases that does not seem to be diminishing over time. The batteries should be redirected to check that the protection against severe cases does not wane and protection against antibody-mediated infection does not decline.
In a young population, without immunosuppression or difficulties in the immune system, the fourth anticovid vaccine “does not have a greater impact,” according to the expert. “The fourth dose that it does is raise your antibodies a little, but they quickly decline. The usefulness of this vaccine is the prevention of serious cases. We have to stop thinking that we can cut the transmission of the virus by vaccination; it is impossible to stop the viral infection with four, five or six doses. Already with three doses you have viral protection against serious cases that is long-lasting and that decays very little over time. The fourth dose does not substantially improve that because it is already very high and The protection against infection does not improve it circumstantially compared to what you already have with the third one, “he assured.
Instead of betting on booster doses, the virologist is in favor of adopting new strategies against covid-19 protection that include, for example, updated vaccines year after year based on the dominant variant.
“Now generic antibodies have begun to be exempted against all the variants that circulate. We have to start thinking about other technologies, multivalent, nasal vaccines against several variants,” he said. Among them, she mentioned aerosolized injections, which require a nasal spray and aim to generate immunity at the mucosal level to prevent infection.
“If we want to lower transmission levels (in the world), the only way is going to be with aerosolized vaccines. There is no booster that you manage to stop the infection with ómicron”, he concluded.
Mirazo’s vision coincides with the position expressed by the American professor of immunobiology and molecular biology Akiko Iwasaki about investing in drugs that prevent the covid-19 disease.
“It’s time to invest in next-generation covid vaccines that not only prevent serious illness but also block infection and transmission. It makes sense to induce mucosal immunity to fight a viral mucosal infection,” Iwasaki wrote Monday. in a tweet that introduces his column published in The New York Times.
