AFP, published on Tuesday, May 11, 2021 at 6:02 p.m.
Antibodies neutralizing Covid remain in the blood for at least eight months after infection, according to an Italian study published on Tuesday.
This observation is valid “regardless of the severity of the disease, the age of the patients or the presence of other pathologies”, according to this study carried out by the prestigious San Raffaele Hospital in Milan in collaboration with the Higher Institute of Santé (ISS), the body advising the government on public health matters.
“The presence of antibodies, although it decreases over time, is very persistent: eight months after the diagnosis, only three patients” out of the 162 follow-ups (29 of whom died) were no longer positive for the blood test. detection of these antibodies, explained in a joint statement the San Raffaele and the ISS.
In addition, the early presence of these antibodies is “fundamental to successfully fight infection: those who fail to produce them in the first two weeks after contagion are at greater risk of developing severe forms of Covid-19”.
This study was carried out by the Viral Evolution and Transmission Unit of San Raffaele Hospital, in collaboration with researchers from the Diabetes Research Institute of the same establishment, who developed a specific test for antibodies. by using techniques already used to study the antibodies involved in the autoimmune response underlying type 1 diabetes.
Using techniques already used for the study of anti-HIV vaccines, researchers at San Raffaelle and the ISS have also developed a new method for evaluating antibodies neutralizing SARS-CoV-2.
The study, published Tuesday in Nature Communications, made it possible to “map in an almost exhaustive way the evolution over time of the antibody response to Covid-19”, estimate the ISS and the San Raffaele.
The study was carried out by following 162 SARS-CoV-2 positive patients (67% male, mean age: 63) who presented to the emergency room at San Raffaele during the first wave of the pandemic in Italy. The first blood samples were collected at the time of diagnosis in March-April 2020, the last ones at the end of November 2020.
57% suffered from a pathology other than Covid at the time of diagnosis. The most common were hypertension (44%) and diabetes (24%).