06/03/2021

Data (and not scientists' statements) are the mother of science

3 min
The Pfizer/BioNTech vaccine, shown here, and Moderna's vaccine protect against the new variants of the virus through the T-lymphocyte mechanism.
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"The devil is already here", infectious disease physician Charles Chiu of the University of California, San Francisco, said a few days ago. And he did so in statements to the Los Angeles Times, the second most widely read newspaper in the United States after the New York Times. This assessment referred to the variant of the coronavirus discovered in California. As Chiu explained, the variant is more contagious, more deadly, and more easily escapes the antibodies generated by natural infection and vaccines. "I wish it were different, but science is science", he added. What science was he referring to? Let's look at it.

Between September and January, Chiu and his team analyzed 2,172 viral genomes and saw that the variant had doubled its presence every 18 days from anecdotal to predominant. They also studied 324 patients who had required hospital care and found that those infected with the variant were five times more likely to be admitted to the ICU and 11 times more likely to die. In addition, they observed that infected people had twice the viral load and that in laboratory studies the variant was four times less susceptible to antibodies from people who had passed the disease, and twice less susceptible to antibodies generated by the Pfizer/BioNTech and Moderna vaccines. All of these studies have not yet been reviewed and published.

Although these data, if confirmed and expanded, suggest that the Californian variant may be more contagious, the possibility that it may predominate as a result of some supercontagion event or simple chance cannot be ruled out. In any case, they also suggest that it would be less contagious than the so-called British variant, which was doubling every ten days when it arrived in the United States. The latter variant has wreaked havoc in many countries, but has been brought under control by tightening restrictions and, in places like the UK and Israel, by vaccinating the population. In terms of the severity of the disease and the likelihood of death, of the group studied, only fifteen patients were admitted to the ICU and twelve died. These figures are low and it could be that, if the sample were enlarged, the differences between those affected by the variant and the rest would be insignificant.

Antibodies and T lymphocytes

On the other hand, there are several studies that show that, although antibodies neutralize the new variants less, the body has another protection system that does not fail: T lymphocytes. The problem is that studying antibodies is easy and quick, while studying lymphocytes is slow and complicated. Therefore, conclusions about immunity drawn from antibody studies should be quarantined until they are confirmed by lymphocyte studies.

In a paper published a month ago in the journal Cell Reports Medicine, researchers at the La Jolla Institute for Immunology, the world's leading American institution in immunology, demonstrated that T lymphocytes generated after natural infection are capable of destroying virus-infected cells in a way that is effective against the new variants.

A new study by the same researchers, not yet published in any journal, now shows that the T-lymphocytes generated by the body after receiving the Pfizer/BioNTech and Moderna vaccines are able to act against the so-called British and South African variants, as well as those from Brazil and California. In short, both natural infection and these vaccines protect against the new variants. Reinfections, if they occur, should be mostly milder. As the director of immunology at the Hospital Clínic de Barcelona, Manel Juan, explains, "T lymphocytes are the most important protection we have against viruses".

In light of these data, the California variant is, with what is known today, less diabolical than the British one. This does not mean that we should not monitor developments, nor, of course, that measures should be neglected or vaccination relaxed. It is still the same virus causing a global epidemic. In the present context, however, calling it the devil is perhaps overly alarmist.

One of the things that the pandemic is making increasingly clear is that, now more than ever, the criterion of authority must be called into question. In other words, we should not let ourselves be dazzled by who says what, and we should pay more attention to what they say, and what evidence they provide. Facts are more important than headlines or viral statements.

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