Fernando Simón warned a few days ago that “not all vaccinated are immunized, 10% do not develop immunity”
Alfredo Corell, immunologist: “It’s outrageous. Immunity is not synonymous with antibodies “
Vaccines and immunologists remember that cellular immunity is key, even if it is not measured, and recent studies confirm that almost 100% of those vaccinated develop antibodies
Said this week the Minister of Health, Carolina Darias, when he spoke about the increase in the incidence of covid in Spain, even with cases between people vaccinated with the two doses. “There is a risk that the outbreaks affect other vulnerable people, who are part of the 10% vaccine escape ”.
And ten days ago when Fernando Simon spoke of the risks of increased virus circulation, said this: “If the virus increases, it can end up affecting people who think they are protected. The higher the transmission among the unvaccinated, the greater the probability that a vaccinated but not immunized person will be affected “. At that point, he also alluded to that 10% percentage.
“You have to remember that 10% of those immunized do not generate antibodies, so they can become infected and end up hospitalized. They are exposed to an infection with more serious symptoms and medical conditions ”, he warned. In that appearance, the director of the Alerts and Emergencies Coordination Center says, literally: “Not all those vaccinated are immunized. 10% do not develop immunity. “
Is this really so? Where does that percentage come from and what does it mean? Clarifying it is important, because the idea has become so popular that it is even being used by some laboratories to promote their antibody tests. At the moment, and according to Health data, in Spain there are some 26,000 vaccinated who have been infected (out of a total of 17 million). This represents 0.15% of the people who have received the two doses of the vaccine., a percentage that would be light years away from the 10% that Simón speaks of (in fact, they are 66 times less). Among those who have received only one dose, the percentage of infected rises to 0.4%.
The 10% of “not immunized” Simon talks about would come out of 90% average efficacy that has been calculated in covid vaccines. That, in turn, comes from adding the efficacy of the vaccines that are being inoculated and weighing them with the weight that each one of them is having in the vaccination of the population. That is, add the effectiveness of Pfizer (95%), Moderna (94%), Janssen (66%) and AstraZeneca (76%), but taking into account that Pfizer is the one that is being administered the most. But To know if you can really talk about “not being immunized”, you have to start by explaining what those efficacy percentages mean.
Efficacy of vaccines, antibodies, and cellular immunity
To measure the efficacy of the vaccine, “the protective response generated by the participants in the trials is monitored,” he explains. Amós García, president of the Spanish Association of Vaccination. The way to measure this response has not been specified nor has it been the same in all the trials, so it is not easy to know if there is only one method. But Garcia explains that 95% efficacy, for example, “means that 95 out of 100 vaccinated people have generated a protective response and in 5 this protection may not have been generated against the disease. It means that this vaccine does not work for them, that they can fall ill because they have worse protection ”.
And say that there are “10% of those vaccinated not immunized” it is right? “Yes, that’s correct, that’s what clinical trials have shown. In 90% a good response would have been generated and in the other 10% no “, says the vaccinologist. “10% is expected, comes from the information that has been received by the companies. Although I would not say that “there is” 10%, but that “there may be”, because it is an estimate, based on the clinical trials that were carried out at the time ”. But is it possible for one in 10 vaccinated people to get sick? We asked him. “There’s a chance. It cannot be affirmed, it must be considered as a possibility ”.
Not everyone sees it that way, some believe that 10% should be explained very well, because it has many nuances. The immunologist Alfredo Corell remember, to begin with, that “immunity is not synonymous with antibodies “. Is much more. “To say that 10% of those vaccinated are not immunized is outrageous”, he warns. “Measuring antibodies is not synonymous with immunity, because you are forgetting the IGA, for example (an antibody that is not measured), or cellular immunity.”
The vaccinologist Carlos Rodrigo matches Corell. “It is outrageous to say that like this, dry stick, is not to make a good reading. You have to qualify it a lot. They are forgetting about cellular immunity, for example. And, furthermore, behind that 10% there may be many reasons, much more than a vaccine escape ”.
Rodrigo explains that “there are people who do not produce antibodies due to an immune problem, but there would never be so many”. Corell seconded. “That a person does not respond to the vaccine at all and does not generate any immunity? That is very rare, it only happens with immunosuppressed people “. But the vaccinologist explains that simple things can also happen such as that the dose has not been set correctly, for example, or that the issue of cold has not been well controlled in Pfizer and Moderna … “In a massive vaccination, there are multiple factors in practice that can go wrong. That percentage could be the sum of all those situations that can occur “.
Health sources qualify Simon’s statements. They explain that “That 10% percentage must be read backwards: the average efficacy of covid vaccines is more than 90%, it is very high. We cannot scare the population ”. And remember that “No vaccine is 100% effective. The flu vaccine, for example, is 75% effective ”. Rodrigo insists on this. “A 90% effectiveness is spectacular.” And underlines that “The good news is that vaccines are extraordinarily effective.”
Only the antibodies are measured, not the cellular response
“There are people who do not respond by forming antibodies, but they are few. And even if there are no antibodies, the cellular response would be enough, in general. But at the moment it is an enigma, because it is not measured ”, warns the vaccinologist Carlos Rodrigo. “It would be necessary to see if, when the virus arrives, there are cells that are capable of removing all the defenses and that are effective. We will need years to find out. It would be necessary to know who has not produced antibodies and to follow up on those people ”.
That cellular immunity is the response that T and B cells generate to respond to infection. And it is very important, because in addition to attacking the virus, they generate memory. That is, they are what allow our body to remember the virus and activate a good response to it, if there is an upcoming infection. What has been seen so far is that cellular immunity against this virus is more powerful and long-lasting than that of antibodies. And vaccines also induce it, although they are more focused on the production of antibodies.
Antibodies in almost 100% of those vaccinated
Those who are providing more and better information on this are the British. The UK is closely monitoring vaccination in that country, and a couple of studies from this week confirm that antibody protection with the two doses of vaccine is very high.
One of them, the REACT-2 study of the Imperial College, is based on tests carried out in May on more than 207,000 vaccinated people. The results reveal that “About 100% had antibodies to the virus two weeks after receiving their second dose of Pfizer or AstraZeneca.”
Specific, the prevalence of antibodies among those who had received the Pfizer vaccine was 100% two weeks after the second dose, in all age groups younger than 80 years. Above 80, the effectiveness was reduced a little: to 97.8%. For those vaccinated with AstraZeneca, the prevalence was 100% in people aged 18 to 39 years, then gradually declining with age, reaching 83.6% in those older than 80 years.
This other study that was published a month ago in the journal BMJ is from Virus Watch at University College London. The immunity of 8,517 adults in England and Wales, with a mean age of 65 years, has been studied. Researchers found that 96.42% of people who had received Pfizer or AstraZeneca (the two vaccines given there) had developed antibodies 28 to 34 days after the first dose, with that percentage increasing by 99.08% if they looked within seven to 14 days after the second dose.
“Our data indicate very high seroconversion rates after a single dose of either vaccine, with almost complete seroconversion after a second dose, in people without evidence of previous infection, “says Maddie Shrotri, who led the investigation.
Why do you get infected if you are vaccinated?
The Imperial College study already warns that “the presence of antibodies alone does not necessarily prevent infection.” And Corell insists: you can get infected by being vaccinated, and that doesn’t mean you don’t have antibodies. It has its explanation. “You can have IGG antibodies, which are in the blood, but the route of entry of the virus is the respiratory route and there other antibodies are needed, the IGA, that they are not looking at each other ”, warns the immunologist. IGA is not detected in serological tests, but something else must also be taken into account, “that the vaccine induces more IGG antibodies “. Infection, on the other hand, induces more IGG”.
Getting infected while being vaccinated, he explains, “does not depend on whether you have antibodies, but on what immunity in the blood is not always reproduced in the mucosa, which is where you are going to get infected (the respiratory tract) ”. Current covid vaccines do not induce this immunity in the mucosa. Therefore, it must be clear that they do not prevent contagion.
This is something that has been warning for a long time, among others, the virologist Luis Enjuanes, who is developing a vaccine that will. His will be sterilizing and will prevent infection, as he explained to NIUS a few months ago. But today, it is important to remember that You can get infected and develop a covid with symptoms, even being vaccinated and having antibodies. “But the infection will be very mild, in general it will not go beyond there ”, reassures Corell. Because the objective of these first vaccines was, basically, that the vaccinated person does not end up in the ICU and does not die of covid. And that they are achieving.