One of the most mysterious enigmas related to Covid-19 has been solved: it was in fact discovered why some vaccinated people still end up getting sick developing severe pneumonia that leads them to be hospitalized in intensive care.
The fault lies with some 'crazy' antibodies (auto-antibodies), already present before infection and vaccination, which weaken the innate immune response against the virus.
This is demonstrated by a study published in Science Immunology by an international team in which the Asst Spedali Civili of Brescia, the Irccs Policlinico San Matteo of Pavia, the Irccs Ospedale Bambino Gesù in Rome and the University of Rome Tor Vergata participated.
"This is the first time that it has been explained why some vaccinated people end up in intensive care," said geneticist Giuseppe Novelli of the University of Rome Tor Vergata, one of the authors of the study.
"The result obtained confirms and extends our previous studies, which had highlighted the presence of auto-antibodies capable of neutralizing high concentrations of type I interferon in at least 10% of unvaccinated people with critical Covid-19 pneumonia".
Now these crazed antibodies have also been found in some vaccinated subjects: confirmation was obtained by studying a sample of 48 patients (between 20 and 86 years of age) who had received two doses of mRna vaccine against the SarsCoV2 virus and despite this, over a period of two weeks to four months later,
For each of them, the researchers measured the presence of auto-antibodies against interferon (Ifn), the levels of antibodies against Covid developed thanks to the vaccine and their ability to neutralize the virus.
The results indicate that almost all patients (42 out of 48) had regularly developed antibodies against Covid-19 thanks to vaccination: 10 of them, however, despite having produced antibodies capable of neutralizing the SarsCoV2 virus (as demonstrated by test-tube experiments), they also had auto-antibodies against interferon, just enough to weaken their defenses.
"The presence of anti-Ifn auto-antibodies is therefore at the basis of a response defect in intrinsic immunity that has in fact exceeded the normal adaptive immunity induced by vaccination", underlines Novelli.
"These data, combined with those of previous studies, therefore suggest the need to study the presence of anti-Ifn auto-antibodies to identify those at high risk of serious Covid-19 disease".
