How many of you have known at least one person lucky enough not to have tested positive for coronavirus, despite his family members, sometimes living together, had contracted the infection? Many. Until now it was considered a kind of miracle, but – obviously – there is a scientific explanation. Some researchers are convinced that yesterday published a detailed study in Nature that investigates the existence of a “abortive immunity“, Or the ability that some people would have to” recognize “the Sars-CoV-2 infection and eliminate it even before a molecular test can reveal the positivity. The virus enters the body, but is immediately “aborted” by the body thanks to the immune response developed thanks to the T cells.
“What we didn’t know is whether these individuals really managed to avoid the virus or if they naturally eliminated it before it was detectable,” he explained. Leo Swadling, the immunologist at University College London and first signatory of the study. “Individuals with potential exposure to Sars-CoV-2”, the research reads, “do not necessarily develop swab positivity or antibody positivity, suggesting that they can clear the infection before seroconversion.” Influencing this process would be memory T cells, inherited from some people previous coronavirus infections (normal colds), therefore already present in the body before the pandemic, and become essential to “support rapid viral control”. Thus stopping the infection.
The study looked at health workers in the first wave of Covid in the United Kingdom, i.e. people particularly exposed to the virus. Why, despite the persistent proximity to the disease, many of them not only did not get sick, but did not even develop positivity? The answer would be precisely in T cells, already developed previously, capable of recognizing the coronavirus and producing an antibody response capable of “aborting” the virus, regardless of the variants developed. Blood tests revealed a high dose of T cells in these subjects, more than they showed in blood samples collected before the pandemic and more than people ever exposed to the virus had. Hence, the hypothesis that they had preserved memory T cells. “Exposure to the common cold – explained Swadling – may have given these individuals an advantage against the virus, tipping the scales in favor of their immune system which eliminated the virus before it began to replicate.”
The studio also has another one valence on the vaccine front. While for today we have worked on the antibody response against the spike protein, this discovery could push pharmaceutical companies to investigate the possibility of pointing to another “region” of the virus, namely the proteins used to replicate. One way to remedy what, to date, is the only small discordant note of the serums produced by Pfizer, Moderna and Astrazeneca: their loss of effectiveness over the months.