“Hello Alfredo, I want to consult you on the case of Asun, one of our nurses. I have well-founded suspicions that he contracted symptoms from covid-19 during the first wave of this pandemic. On Wednesday, January 20, she received the first dose of Comirnaty [Pfizer’s vaccine] at the health center. On Thursday the 21st, in addition to pain and heat at the injection site, she noticed a fever above 38, muscle and joint pain, headache, fatigue, chills, and difficulty falling asleep and staying asleep.
The negative antigen test and PCR make me suppose that these symptoms, which persist on Friday the 21st and those that improve on Saturday the 22nd after being recovered on Sunday the 23rd, are unwanted effects of the vaccine. From what is known about the vaccine, could it happen that with the second dose there is a greater reaction? Is it, in this case, advisable, from your immunological knowledge, to receive the second dose of the vaccine? “
This is what Fede, the medical coordinator of a Primary Care Center in Burgos, wrote to me. Messages like Fede’s have been received dozens a day, for about a month. The month in which the first doses of the Pfizer and Moderna vaccine for COVID-19 based on the modified RNA have been administered. But also daily I receive another repeated query: If I have already passed the covid-19 with symptoms, do I have to get vaccinated?
Universal vaccination by priority groups
So far, the answer from the scientific community and health authorities to this question has been “yes.” The Comirnaty leaflet insists that everyone should be vaccinated (whether or not the disease has passed). Even the prestigious medical journal New England Journal of Medicine assures this emphatically in a frequently asked questions and answers about vaccines.
Also an article to disprove hoaxes about vaccines published on this same platform and signed by experts in different areas of knowledge indicates that it is false that you do not have to be vaccinated because you have had the disease.
But let’s go back to Asun’s case. Being a nurse in a primary care center, I asked Fede to give me the history of his serology. He had passed several rapid antibody tests. These tests measure the presence of IgM and / or IgG in the serum of patients.
The first antibodies that are produced against any infection are of the IgM type. Later they are replaced by IgG (or IgA) that has a greater neutralizing capacity (among other biological activities). We see that in the case presented IgG was produced and was preserved up to a week prior to vaccination.
The evidence in favor of universal vaccination is as follows:
- Even after the disease is over, natural antibodies can decline over time and lose their ability to block (neutralize) the virus.
- There is preliminary evidence that immunity generated by vaccines may be longer and stronger than natural immunity (after infection).
Should we rethink this strategy?
Clearly yes. At least at a time – like the current one – when we don’t have unlimited vaccine availability. In addition, the third vaccine to arrive in Europe (AstraZeneca) should not be administered to people over 65 years of age, as it has not been sufficiently tested in this age group.
This is reflected in the file of the European Medicines Agency itself, although it is indicated below that there is no “contraindication to its administration, since other vaccines have worked well in these ages”. But this assumption should not govern the university guideline, because for the same reason none of the vaccines is being administered to young age groups, in which it has not yet been sufficiently tested.
So let’s go back to the beginning. When the immune system responds for the first time to an infectious agent, it generates cells (called T and B lymphocytes) that set in motion mechanisms to kill the microbe, leaving a few “memory” cells in our blood.
So if that same microbe were to repeat the infection a few years later, it would find itself with a much more powerful and effective immune system to fight it.
Vaccines are based on this characteristic of immune memory. Well, they are really “simulations” in which the immune system is forced to respond to a supposed microbe.
After this “deception” generated by the vaccine, our defenses will leave a circulating memory in case the microbe infects us again in the future. So yes… you understood me. If we pass the real infection, our defenses will leave memory cells and antibodies circulating. And the big question is for how long?
At this time we do not know how long natural immunity (induced by infection) or artificial immunity (induced by vaccines) will last. Although we already know the minimums: 8 months for the natural one and 4 or 5 months for the artificial one.
Natural immunity has proven to be effective in the vast majority of cases, as there have hardly been reinfections (and with the amount of virus circulating, it is expected that thousands of daily exposures are taking place in people who have already passed the disease). In addition, the infection has been shown to produce protective immunity in macaques that are re-exposed to the virus.
Basic Functioning of the Immune Response
At a time like this, when we do not have universal doses of vaccines, it seems reasonable that those who have passed the infection symptomatically and have generated an immune response should not be vaccinated.
We are seeing people like Asun who have a very strong reaction to the vaccine. We will not give them the second dose. They are already immunized. Even if they did not have detectable antibodies, they would also be thanks to memory cells, which can start the manufacture of new antibodies in a few days.
Not everything in our defenses are antibodies, let’s not forget. The Spanish Society of Immunology has recently issued a statement positioning itself in this debate, betting not to vaccinate those already immunized under 60 years of age.
In these situations, it is also necessary to apply criteria of prudence and evaluate the risk / benefit of the decisions. What is the greatest risk? That an immunized person has lost the neutralizing power of their antibodies? Leave unvaccinated elderly people and other risk groups such as chronically ill patients who have not yet passed COVID-19 and are not immunized? It is perfectly clear to me: we must save doses of those already immunized and protect the most vulnerable. This is not the time to doubt one of the essential mechanisms of the immune response.
Alfredo Corell Almuzara, Professor of Immunology, University of Valladolid
This article was originally published on The Conversation. Read the original.
