In the midst of controversy over the need to inoculate the entire population with a third or even a fourth dose of the coronavirus vaccine, researchers such as Eduardo Lopez-Collazo They have been warning for some time about the importance of measuring the cellular immunity to really know who needs it and not waste huge amounts of money and resources.
As shown by the study led by Dr. Biomedical Research Institute of Hospital La Paz, “eight months after being vaccinated, you may not have antibodies, but your cells do produce them“However, the complexity and high cost involved in measuring cellular immunity has led governments to be guided solely by the evident loss of antibodies a few months after receiving the full vaccination schedule.
Now, a group of experts from the University Hospital of the Canary Islands (HUC), led by the immunologist Yvelise Barrios and the allergist Victor Matheu, has managed to develop a skin test, a pioneer in the world, which could radically change the game board. “Is easy to do, cheaper and it does not require sophisticated equipment and a laboratory to do it, as is the case with cell tests that are on the market right now,” says Barrios in conversation with digital freedom.
How does it work
At first glance, one could say that the test is similar to those for allergy, since it is about looking for a skin reaction that, in this case, would appear after 24 or 48 hours. “It really is an adaptation of the tuberculin test, which measures the cellular response to the antigen that we use,” explains the doctor. “In the case of tuberculin, an extract of this pathogen is put in. What we did was use a piece of Spike protein“.
When injected into the skin, if the individual has already been infected or has been vaccinated, “they will have T lymphocytes that, if they recognize this antigen, will go to this area of the skin, causing a small inflammatory reaction” . The result will be a Red stain that will allow us to determine that we have a cellular response, “which is what we are interested in measuring”.
The main advantages
In this way, the study of cellular immunity is considerably simplified, since the patient does not even need to return to the hospital to be observed again: “After 24 or 48 hours they send us arm pictures and we can only interpret the result with this”.
All in all, the great advantage of this test is that it could easily reach the entire population. “Let’s say democratizes this type of test, which until now could only be done to small groups of people”, insists the doctor, who emphasizes the large number of vaccines that we could save if we use it to determine who really needs them and when: “Continuing to vaccinate massively entails a very significant investment and mobilization of resources and we believe that, once this first phase of the global emergency has passed, in which it was necessary to vaccinate everyone in a fast and very intense, we are at a time when we can already try to find optimization strategies”.
Thus, Dr. Barrios celebrates that the Government has come to its senses and has decided to delay the third dose for those people who have contracted the virus in recent months, since she underlines that “the hybrid immunity -the one that gives the complete vaccination pattern followed by infection- is the most powerful”.
clinical trials
The test in question has been successfully tested in patients with primary immunodeficiencies -those who do not produce antibodies because they have a failure in their immune system-, renal transplant recipients and even a group of health of the University Hospital of the Canary Islands. In fact, in this last group, the test made it possible to recommend a booster dose to one of the doctors who had lost his cellular immunity before the Government implanted the third dose for the sector.
In addition, it has served to corroborate two things: that cellular immunity lasts much longer than antibodies and that those who have suffered from the coronavirus in a more severe way have a much stronger response than those who have suffered mild symptoms.
Canada will implement it this year
When in the summer 2020 these researchers realized the potential of the test they had in hand, they tried to seek the support of a technology company that could make it a reality beyond the four walls of the Hospital Universitario de Canarias. However, they did not succeed, perhaps because its main limitation is that it offers a purely qualitative information. That is, it is capable of determining whether or not a person has cellular immunity, but not how much.
“We assume that they were looking for more sophisticated methods, with deeper information,” explains Barrios. However, time has ended up proving them right: “After all, the objective in a pandemic has to be to achieve something that we can use in a large population and the methods that have been developed so far are much less plausible to do to large groups of people.
The little commercial interest they perceived at the beginning made them choose to keep the “academic merit of being the first to put this technique into practice” and, instead of applying for a patent, they published the results to put them at the service of the entire community. scientific. Today, almost two years after the pandemic was declared, there is still nothing better on the market, so the Canadian company Biovaxy has been put to work in order to bring it to market “at the end of this year“.
Dr. Barrios acknowledges that, after all the work done, they still have a “sweet and sour taste” for not having managed to get the test to land earlier in the Spanish market. However, both she and Víctor Matheu – the allergist with whom she has worked side by side – are pleased to have been pioneers in putting into practice a technique that in the near future could be decisive.
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