While we are talking about the upsurge in new cases of patients affected by Covid-19, many of them will not realize that they have had the disease. Indeed, the study by Karolinska University Hospital in Stockholm shows that many people infected with Covid-19 in a mild or asymptomatic form, have developed a immunity mediated by “T cells” (a category of leukocytes that play a big role in the secondary immune response).
However, these same “T cells” have also been found in subjects who have never been in contact with SARS-CoV-2. The reason, still unknown, could be the result of a past infection by a common coronavirus (HCoV).
There are seven identified coronaviruses to date. Four of them are prevalent worldwide, the Alphacoronaviruses (229E and NL63) and Betacoronaviruses (OC43 and HKU1). They were discovered several years ago, the first in the mid-1960s. The other three are identified since the start of the new millennium : SRAS 1, MERS, SRAS-CoV-2.
Much research has focused on the relationship between T cells and the coronavirus. Some researchers and companies are talking about the development of a possible vaccine about which there is a lot of speculation, medical uncertainty and polarization of minds.
To date, the vaccines currently being researched do not target a specific, personalized and individualized, focusing on a general approach.
Italian researcher Andrea Savarino, one of the first to study the effects of chloroquine and its derivatives on the SARS 1 virus in 2003, foresaw for the Covid-19 that:
“The immune response should not be dispersed, but focused only on certain parts of the virus”.
Son équipe, of the Higher Institute of Health Andrea Savarino has been studying this subject for a while and the progress of their work is such that a patent has been filed.
“Yes, this is an international collaboration. We have filed a patent application in the United States, which will then be extended internationally.”
The optimal approach would therefore be a personalized immunization against parts of the virus essential for its replication, so as not to disperse the immune response. One of these parts of the virus is Spike’s surface glycoprotein on which the effects of the drug chloroquine and derivatives like hydroxychloroquine occur.
This drug is able to inhibit the replication of certain coronaviruses, at least in vitro. Its action is manifested by the” inhibition of the attack of a sugar (sialic acid) on the ACE2 receptor, that the virus continues to enter the cells. A component of their vaccine involves the part of the glycoprotein Spike which recognizes sialic acid on the surface of cells to be attacked.
It is necessary to better understand what this concept of“tailor-made” vaccine immunization, adapted to the different immune responses of individuals:
“Simply put, each of us has a combination of protein variants (HLA I). Our cells have a signaling system to the immune system when invaded by an outside agent such as a virus. This signaling system causes pieces of virus to “mount” on this protein, which activates the immune system. However, “recognized coins” are not the same for all individuals, and “suitable parts ” have to be administered to each individual in order to immunize them” .
Indeed, decades of research in the study of HIV, have made it possible to establish with relative certainty that not all CD8 “killer lymphocyte” mediated responses provide defense against the virus. Many can even be counterproductive, as they direct the immune response to changing portions of the virus, which then escape the response itself. Studies on macaques and humans have shown that immunity is only effective when directed to certain parts of the virus that are not mutable, because they are fundamental for viral replication.
Asked about the timetable for arriving at safety and tolerance tests on humans, Andrea Savarino replied:
“At the moment, we are testing the approach on mouse. In developing a vaccine, the issue is not only what portion of virus to use, but also what is called l’adjuvant, that is, a carrier which allows small antigens to become immunogenic or to elicit an immune response.
Once we fix this mouse issue, we plan to start a human clinical trial, with a little luck at beginning of next year ”.
To be continued
Peter D’Angelo is an author and director of documentaries for television (Rai) and a journalist. He has conducted several surveys for Il Fatto Quotidiano, Corriere della Sera, La Repubblica, Panorama, Il Tempo, L’Espresso and Il Venerdì.
He has signed several polls for Il Fatto Quotidiano, Corriere della Sera, La Repubblica, Panorama, Il Tempo, L’Espresso and Il Venerdì. He has also collaborated on various television programs: Report (prime time investigations), Presadiretta, Le Iene, Petrolio, Mi mandda Raitre and Agorà.