The Spanish company Ingenasa has developed an antibody test prototype specifically directed at protein S, against which vaccines act.

Results of two rapid antibody tests with the same sample.

Some innovations are not made to be used massively, which does not mean that they are more than remarkable from a scientific point of view. This is the case of an antibody test -still in the prototype phase- designed by the Spanish company Ingenasa that allows detection with a small blood sample whether or not a vaccine has been effective.

This was proven in person by the scientific director of the Research Institute of the La Paz University Hospital, Eduardo López-Collazo without knowing what result was going to come out. He did it for a program on Madrid’s public television Telemadrid.

López-Collazo has already received both doses of the Pfizer BioNTech vaccine and should therefore be immunized. But the drug is 94% effective, so there is always some chance that the body will not react correctly and no coronavirus antibodies are developed.

Scientist Eduardo López Collazo explains the result of his antibody test.

The question that arises is, therefore, how can one know if the vaccine has been effective. And the answer is that there is a type of rapid test – the kind that detects antibodies – that allows it. Y It is also a Spanish product.

“What happens when one suffers Covid-19 is that the body reacts against the virus and creates antibodies against it. When this happens naturally, the antibodies that are created go against the whole virus but, with the vaccine, things change ”, explains López-Collazo to EL ESPAÑOL.

What is done when developing vaccines is for the body to create antibodies against certain proteins or bits of the pathogen. And, specifically, there is a protein that is they fell in love all vaccine creators: the S or spike. “It is the one that binds to the ACE2 receptor, which is the gateway for the coronavirus,” says the scientist.

When hearing about antibody detection, everyone thinks about general antibody tests, most of them fast, those that have been practiced so far – always, according to the Health recommendation, in the context of epidemiology and public health studies – to find out who has passed the Covid-19, something especially useful to detect those cases of the first wave, when there was very little ability to test.

However, this type of test generally detects general antibodies. And no, not all of them would help to know if a vaccinated organism has reacted well to the drug and would prevent infection. The reason: not all detect antibodies to protein S.

“People are going to start having to learn some immunology,” jokes IdiPAZ’s scientific director. What a test has to locate to know if a vaccine has worked it is precisely the antibodies against protein S.

Ingenasa has developed a specific test for it and it is the one that López-Collazo tried, although not only. The scientist underwent the conventional rapid test and compared the results with the new one. The result: two different ones, one negative and one positive.

Result of the two tests.

Result of the two tests.

The conventional, negative, reported that the researcher the disease had not passed naturally. Reading his results, no one could have deduced that he had been vaccinated or that he had protection against the virus. No sign of the S protein.

The second, the prototype, yes it found out. The double line (the red one) indicated that there were antibodies to protein S in that blood, which they will take care of keeping the virus at bay if you try to infect it.

However, despite this scientific advance, López-Collazo is clear that he does not recommend people who have been vaccinated to have this test. “The important thing is that we all get vaccinated, and if someone belongs to the percentage that has not developed antibodies, it will be seen protected by herd immunity“, He concludes.