-Doctor, good morning. Sorry to bother you, I was summoned for the third dose. I have Sputnik, Modern and now I would have AstraZeneca. Do I accept it? Isn’t it a lot of mixing?
After hours of thinking about whether or not she should write to her oncologist, Josefina sent the message. It was 12 noon on Monday, November 1, and she didn’t want to bother her doctor: she imagined her going crazy with patients, in an office that by that time would already have an occupation similar to that of a subway car during rush hour. But the call to put the arm for a third dose against the Covid-19 infection –a third vaccine dissimilar to the previous one and the previous one– It generated doubts.
For one thing, he didn’t want to miss out on the opportunity to protect himself against the virus. She cared about being vaccinated to make plans and project the future: for a year and a half her life had been minimizing risks, in a world behind closed doors, by having their defenses weakened by cancer treatment.
But on the other hand, feared adverse side effects and he wondered if there was evidence on the impact that three different vaccines could have on one person, and especially on a person receiving chemotherapy.
Immunosuppressed patients and doubts about vaccine mixtures. Reuters Photo / Dado Ruvic
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“All vaccine combinatorics were studied in two-dose schedules. It is true that there are not yet, at least in the same proportion, three-dose studies, nor a specific study on the Most Modern Sputnik plus Astrazeneca scheme, but all over the world we have millions of people immunized through a heterologous vaccination (with doses from different laboratories). This strategy proved to be safe and very effective “, says by telephone the doctor in Biochemistry Jorge Geffner, holder of the chair of Immunology of the Buenos Aires’ University.
Safety and effectiveness they are two of the three parameters with which the performance of vaccines in a population is evaluated. The other factor is immunogenicity, which refers to the immune response, that is, the generation of antibodies. This response is what all vaccines seek, even if they are not designed in the same way or work with the same logic.
Within the scheme offered to Josefina, Sputnik vaccine and Astrazeneca they are similar, they even have a common platform. The two take genetic material from SARS-COV-2 and introduce it into another virus, called adenovirus. The Russian vaccine uses human adenovirus, instead of a chimpanzee one, as do the doses developed by the University of Oxford.
Instead Moderna is the different of the trio. Use a new technology, messenger RNA, which instructs human cells to produce a portion of the spike protein, which by itself is harmless. The same method is used by Pfizer.
“But there is no magic here,” says Geffner. “It is a misconception to stop at the difference in platforms, because the objective is the same: it is sought produce antibodies that block the virus’s ability to infect. What does that capacity depend on? From the protein Spike (spike). The antibodies that produce any of these vaccines, they block the Spike, they make it an ineffective particle. “
The Spike protein is the one located on the surface of the virus. Photo National Institute of Health
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Since April 2020, and given the emergency, the vaccination campaign advanced along a path that combined experimentation with practice and scientific verification. All at a fast pace. But neither before, in the race for the vaccine, nor now, with half the world’s population on at least one dose, has time ceased to be decisive.
“Today, in the face of the advance of the Delta variant, which is already present in a majority way, it would be much more unsafe to leave someone immunosuppressed with two doses, than to give them a third”, says Geffner and adds: “My suggestion is that they give it to them“.
What is immunosuppression
A person can be immunosuppressed for two reasons. Because it has an illness that affects your immune system or because you are low a treatment that lowers your defenses, as in the case of Josefina. The universe is wide. It ranges from cancer or lupus patients, through transplant patients and patients with liver disease, to men and women with kidney failure and on dialysis treatment.
“The vaccine mix may sound messy but we know it is effective“, says Elena Obieta, infectious disease doctor and member of the Argentine Society of Infectology.” We are certain that with the same vaccine an immunosuppressed person generates fewer defenses than a healthy person, that is why it is considered that this population has just completed the scheme with a third dose “.
In these cases, the application of a third dose does not seek to stop a supposed immune loss, but to balance: help these people reach a more robust level of defenses. Most immunosuppressed patients need three doses to obtain the same protection as the rest of the population obtains with two.
“It is logical that there are doubts among patients. But those doubts have to be cleared in the correct places, not in social networks or WhatsApp chains, but before health professionals or official organizations”, says Obieta and continues: “Immunosuppressed people have to get the vaccines available. We need you to complete your schematics. Sticking with two doses and ignoring a third would be a risk, because your immune system is weaker to deal with the Delta. “
Immunosuppressed people need to receive a third dose to complete their Covid vaccination schedule. Photo Maxi Failla
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Since the end of October, when the City and Province of Buenos Aires announced a third dose for people with immune compromise, consultations like Josefina’s with her oncologist were replicated in clinics and among health professionals. In particular, oncologists who went -and still go- to infectologists to know what indication to give.
Next Wednesday, November 10, Josefina will visit her oncologist and from there she will come out with a definition. Now, for this note, by WhatsApp message he says: “We patients already have a painful path to travel and doctors are overwhelmed, with more patients and many of them in serious situations due to controls or treatments that they could not do during the quarantine. We feel pressured and, above all, alone. I would like not to have to invade my doctor and receive a clear communication from the authorities. I am not standing in an anti-vaccine place, on the contrary, I just need information to decide“.
Who is receiving a third dose against the coronavirus?
In the City and Province of Buenos Aires, together with immunosuppressed people, they were summoned those over 50 years of age who have been inoculated with Sinopharm.
The Chinese origin vaccine is developed with inactive SARS-COV-2 virus: entering the body, it does not reproduce or cause disease.
People over 50 who have been vaccinated with Sinopharm will also need a third dose. Photo Andrés D’Elía
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Its methodology is the same as that of other vaccines, such as polio or influenza. Thus, because it has a “conservative” platform, it is considered one of the safest options with almost no adverse effectsThat is why it was decided to apply it to boys.
But at the same time, as shown in scientific studies, Sinopharm is a vaccine that generates a lower level of antibodies compared to others. For that reason, and unlike what happens in immunosuppressed people, in people over 50 years a third dose will act as a booster.
NS
