MOSCOW, 10 Jan. Researchers at Imperial College London have found that high levels of T cells created by the body when infected with the common cold-causing human coronaviruses can protect against COVID-19 infection. An article published in the journal Nature Communications. Not all people, even in the absence of vaccination, become ill with COVID-19 after exposure to the SARS-CoV-2 virus. Scientists suggest that such people have a very strong first line of defense — T-cell immunity, which they developed when they met other human coronaviruses that have long been present in the population. The authors of the article present the first evidence that T cells induced by other coronaviruses can recognize and build protection against SARS-CoV-2. The study began in September 2020, when most people in the UK were neither infected nor vaccinated. against SARS-CoV-2. It was attended by 52 people who lived with those infected with the coronavirus, but did not get sick. All participants underwent PCR tests at the very beginning, and then 4 and 7 days after confirmation of infection in their loved ones. However, all three tests were negative and blood samples were taken from those with whom they were engrafted within 1-6 days after infection, which allowed the scientists to analyze the levels of pre-existing T cells induced by previous colds from coronavirus infections. It turned out that these cells recognize the proteins of the SARS-CoV-2 virus — external surface proteins (spike, membrane and envelope), as well as internal proteins, including the nucleocapsid, which packs the genetic material of the virus, and ORF1 is part of the replicative mechanism of SARS-CoV The researchers found that the level of cross-reactive T cells was significantly higher in 26 people who did not get infected, compared with 26 people who did get infected, and the T cells themselves in such coronavirus-resistant people were targeting internal proteins SARS-CoV-2, not a spike protein on the surface of the virus. Scientists have found out how influenza vaccination affects the risk of contracting COVID-19 Existing vaccines do not elicit an immune response to these internal proteins. The authors believe that their results will help create a second generation vaccine that protects against all current and future variants of SARS-CoV-2. According to the researchers, such vaccines will provide long-term protection because T cell responses persist longer than antibody responses, which weaken for several months after vaccination. “Our study provides clear evidence that common cold coronavirus-induced T cells play a protective role. a role against SARS-CoV-2 infection, «said research leader Professor Ajit Lalvani in a press release from Imperial College London.» These T cells provide protection by attacking proteins within the virus, not the spike protein on its surface. » «The spike protein is under strong immune pressure from vaccine-induced antibodies, which stimulates the evolution of mutants that escape the vaccine. In contrast, the intrinsic proteins that the protective T cells we have identified mutate much less. Thus, new vaccines containing these conserved internal proteins will induce a broad protective A T-cell response that should protect against current and future SARS-CoV-2 variants, «the scientist notes. Emphasizing the important role of T-cell immunity, the authors note that you should not rely on it alone. In their opinion, only a fully vaccinated person can consider himself to be reliably protected from infection.
