Covid infections have been detected in vaccinated, especially in residences: older people and those who were vaccinated the first
Immunologists explain that “the immune system also ages, older people have a worse response to both infections and vaccines”
Antibodies decay over time, but the cellular response to the virus and its variants is more powerful and durable
What’s going on? There are several answers, but above all it must be remembered that the vaccine is not 100% effective in preventing covid cases, much less contagion. Nobody said it was, and time is confirming that it is not.
All the Covid cases that are being seen among vaccinated have several things in common: they occur in very old people, who were the first to get vaccinated, at the beginning of the year. But in addition, they coincide in time with the increased circulation of the delta variant, which makes the virus much more contagious than before and circulate more.
Many of the detected cases, in fact, are of this variant. Given this, several questions arise:How heavy is age in what is happening? How much is due to the passage of time and drop in antibodies? Are both influencing?
Vaccines, especially messenger RNA vaccines (Pfizer and Moderna), have a very high efficacy in the face of severe covid, hospitalization and death, even in the case of the delta variant. Namely, prevent, in a very high percentage, that the vaccinated end up in the ICU due to covid or that they die. You can get it, but most likely a mild or asymptomatic covid will pass. It’s what it was all about.
It should not be forgotten that they were authorized in record time and as emergency vaccines, to contain a pandemic that was rampant and wreaking havoc across the planet.
“The tests were done on the premise that, if people contracted the virus, they did not come to the ICU, and for the moment that is what is happening“, remember Joaquin Lopez-Contreras, infectologist and clinical head of the Infectious Diseases Unit of the Sant Pau Hospital in Barcelona.
The vast majority of infections detected among those vaccinated are mild. “The vaccine is very, very effective. The reduction in incidence in the elderly is spectacular, but it is clear that not 100% ”, he warns.
One death and several outbreaks in residences
This Monday we knew the news. An 80-year-old man died of covid a few days ago at the Bellvitge hospital, in L’Hospitalet de Llobregat (Barcelona). It had been two months since I had the full schedule of the vaccine. “It is an anecdote, an exceptional case”, declared the head of the Intensive Medicine Service of the hospital, Rafael Máñez, in an interview with TV3. In it he explained that this patient was vaccinated but had a very low level of antibodies, and also pointed out that vaccination in older people “does not have the same efficacy” as in young people.
This weekend, the President of the Generalitat, Pere Aragonés, and the Minister of Health, Josep María Arguimon, already referred to the admission to the ICU of people with two doses of the vaccine. On Catalonia, where the fifth wave is more advanced than in other parts of Spain, have been detected outbreaks in fifty nursing homes in the last days. But this does not only happen there.
On Madrid, the Minister of Health Enrique Ruiz Escudero warned, a few days ago, of the hospitalization of people with the complete vaccine schedule, although he described it as something “exceptional.” And in Galicia, there are eight elderly infected in a nursing home of Betanzos (A Coruña). All, over 90 years old, and all, vaccinated since March. The medical manager of the center also assures that these are cases of the delta variant.
Two of those infected in that residence died this weekend, but both had previous pathologies (heart disease). It is about a 100-year-old woman, who died in the residence itself, and a man who died in a hospital.
From the center they don’t know how to specify whether the cause of the deaths was covid or not. They know they died from covid, but not if they died from covid, It is not the same. The other six infected elderly are asymptomatic.
Outside of Spain, outbreaks have also been detected in residences. The research carried out in a residence in France, in which infections were detected between 22% of residents and 22% of workers. The infected residents had a higher mean age (91 years) than the uninfected (87 years), and were vaccinated.
Instead, none of the infected workers were vaccinated. In the center, three out of four residents and half of the workers had the full schedule of the vaccine. According to the data of this study, the effectiveness of the vaccine (Pfizer) among the oldest would be around 68%.
Immunosenescence: the immune system also ages
Returning to the question of why this happens and the possible answers, the first one that immunologists point to is the so-called “immunosenescence“That is, the immune system of older people no longer works as well as it should. It is explained by the immunologist Alfredo Corell: “With aging, the immune system also ages, therefore Older people have a poorer response to both infections and vaccines. And it is possible that some of them may need a third dose in the future for better coverage ”.
Corell cautions, however, that the vast majority of cases of contagion between vaccinated are not being serious, despite occurring in older people. “In most of the outbreaks, infections in vaccinated are being -in the vast majority of cases- asymptomatic or with mild symptoms ”.
Although, he cautions, there are always exceptions. “It cannot be ruled out that, in some people who have not responded well to the vaccine or whose antibodies have declined very quickly, the presentation symptoms (symptoms) may be a little higher.”
The infectologist also insists on this Joaquín López-Contreras. He explains that in the outbreaks detected in the residences, “all the cases are mildly affected, patients who did not need hospitalization, were managed in their own residences.” Regarding the died in Bellvitge, ensures that “It was positive but his death was due to another pathology, it is not related to the covid.”
Explain what in his hospital they have not had income from vaccinated with covid, and that they have no record of it in any other, but there have been cases of “workers who have received the vaccine and become infected” and that “most have developed minor symptoms, as if it were a flu, and some have been asymptomatic”.
Passage of time, drop in antibodies and cellular response
There are another factorapart from age What may be behind these infections between vaccinated people: the passage of time, and the consequent drop in antibodies. The oldest of the residences they were the first to be vaccinated. For those who received the vaccine in January, six months have passed.
On this, Corell is very clear and reassures about it. “It does not seem that in the general population there is a loss of antibodies, and of immunity in general, after 6-9 months. In fact, this week there have been articles about a powerful cellular response, both T and B cells, in addition to different variants. Y syou have seen that T cells are more resistant to variants than the antibodies themselves ”.
This is something that has been pointing out for months: that the cellular response is key, too, against the variants of the virus. In fact, an experimental vaccine is already being developed that will try to further stimulate the immune response of T cells.
So the immunologist remembers something important. “Neither do you have to play all the cards to neutralizing antibodies, because even if they decline over time, we know that those memory T and B cells, which in the event of a new infection can produce a response, both cellular and antibody, in a very short time and with great efficiency ”. This has been confirmed recently and, for many, it would even allow to venture that the immunity of the covid vaccines can last many years, or even a lifetime.
Will the third dose be necessary? According to the cases
In the middle of this panorama, Pfizer continues to insist on the need to inoculate a third dose of your vaccine. Although both the CDC and the US FDA have stopped its feet, not considering it necessary “for now”, the pharmaceutical company continues to press for its approval. Relying, above all, on the increase in infections among those vaccinated in Israel, which has already announced a third dose for at-risk adults.
According to data from the Israeli Ministry of Health, in the cases of contagion detected in vaccinated, two circumstances are repeated: delta variant and people vaccinated in January. But they are still being investigated, and they warn that a cause-effect relationship cannot be established.
Experts from the Ministry itself also highlight that lMost of those who were vaccinated first were from advanced age and therefore had a weaker immune system.
On the possibility of this third dose, Corell believes that, with the data on immunity that we have so far, “It is not possible to think that in a healthy general population it is necessary to revaccinate or give a memory. But the most vulnerable population -people with less defenses, either because of their age or because they have a concomitant pathology- it is possible that they may need to receive a booster dose in a short time ”.
Lopez-ContrerasFor his part, he also points out that it is not yet clear “if we will all need a third dose or only immunosuppressed people ”. The latter is what another immunologist, Marcos López Hoyos, pointed out a few days ago. If needed, the infectologist explains that “The reminder already has other vaccines, such as tetanus or pneumococcus.”
For now, this Monday, and at the request of Pfizer, there has been a meeting behind closed doors with FDA officials to present their data on the effect of the third dose, which according to the company, would increase the level of antibodies between 5 and 10 times. The fact that the meeting is behind closed doors, again without sharing the data that Pfizer considers so relevant, has been criticized from the scientific community, for lack of transparency.