Once the anti-Covid vaccine is done, how calm can you be at the thought of being protected from the virus? Basically how do we know to what extent we are immune, and for how long? To dispel these doubts is a new rapid swab capable of measuring the extent and duration of immunity to SARS-CoV-2, therefore capable of providing valuable information on the timing and methods of future vaccinations against Covid, particularly in individuals. vulnerable.
Covid, ‘old’ and updated vaccines: how much we are protected from the new sub-variants
by Irma D’Aria
The new blood test was made by researchers at Mount Sinai Medical University of New York. A test that will allow, the researchers promise, large-scale monitoring of population immunity and the efficacy of current vaccines to help design revaccination strategies for vulnerable immunosuppressed individuals.
I study
The study was published in Nature Biotechnology. The test takes less than 24 hours to perform and can be used by a wide range of the population. It works by measuring the activation of T cells, which are part of our adaptive immune response to SARS-CoV-2 infection or vaccination and help protect against severe outcomes or death.
“We know that vulnerable populations don’t always activate an antibody response, so measuring T cell activation is critical to assessing the full extent of a person’s immunity,” said one of the study’s senior authors. Ernesto Guccioneprofessor of Oncological Sciences and Pharmacological Sciences, at The Tisch Cancer Institute of Mount Sinai.
Objective: to measure T cells
Furthermore, the emergence of SARS-CoV-2 variants such as Omicron, which elude most of the neutralizing ability of antibodies, indicates the need for tests capable of measuring T cells, which are more effective against emerging variants of concern. Because long-term protection from viral infection is mediated by both antibodies and the T cell response. And many recent studies highlight the importance of determining T cell function in individuals who have recovered or been vaccinated against Covid for the purpose of a better strategy in vaccination campaigns.
Covid, how often can you get infected? Up to four times a year
by Donatella Zorzetto
The method
However, prior to this study, measurement of T cell responses was rarely performed due to the technical challenges that come with it. In conducting this study, Duke-NUS Medical School’s Mount Sinai researchers and partners optimized qPCR-based tests that had the potential to be scalable, sensitive and globally accurate tests.
The researchers narrowed their attention to the two tests that offered the greatest scalability. One, the qTACT test, was accurate and sensitive but had a relatively longer processing time of 24 hours for 200 blood samples, a moderate price, and an average level of technical skill.
The other, the dqTACT test, was accurate and had reduced processing time and cost, and required minimal laboratory experience, making it easy to implement. The dqTACT test has recently obtained the European CE-IVD (in vitro diagnostics) certification, while clinical validation by the Food and Drug Administration and the European Medicines Agency is underway.
Protection goes down
That the protection guaranteed by the Covid vaccine decreases over time was already shown towards the end of 2021 by an Israeli study. Protection that was seen to decrease after about 6 – 4 months from vaccination and which continued to progressively reduce until it exposed the risk of incurring infection.
Covid, infected despite the vaccine: what does it mean?
by Aureliano Stingi
The study conducted by several Israeli institutions, including the Ministry of Health, was published in the New England Journal of Medicine. It analyzed the infections that had occurred during the summer peak of 2021, sifting through data from 5 million people fully vaccinated with two doses before the summer. Between 11 and 31 July in this population there were 13,426 cases of Covid, 403 of which were severe. “The SARS-CoV-2 infection rate – the authors of the research clarified – showed a clear increase as a function of the time elapsed since vaccination”.
According to experts, the summer resurgence of Covid was caused, not by the ineffectiveness of the vaccine against the then Delta variant, but by a progressive decline in acquired protection: “If there were not a drop in immunity – they explained – there would be no there would be differences in the rates of infection between people vaccinated at different times “.