High levels of T cells from the common cold coronavirus may provide protection against COVID-19, according to a study from Imperial College London published Monday.
This information could be a new approach to second-generation vaccines. Immunity to COVID-19 is a complex picture. There is evidence that antibody levels decrease six months after vaccination. Well, T-cells are believed to play an important role in providing such protection.
T cells or T lymphocytes are a group of white blood cells that play a major role in cellular immunity. T cells are able to distinguish between types of pathogens with the ability to evolve over time for increased immunity every time the body is exposed to a pathogen.
This is possible because a number of T cells are activated into memory T cells with the ability to proliferate rapidly to fight off infections that may recur. The ability of T cells to remember certain infections and their systematic resistance, exploited throughout the vaccination process, has been studied in the adaptive immune system.
The study, which began in September 2020, looked at levels of cross-reactive T cells produced by a pre-existing common cold in 52 household contacts of positive COVID-19 cases shortly after exposure. This is done to see if they continue to develop the infection.
It was found that the 26 uninfected people had significantly higher levels of T cells than the infected people. But Imperial College London did not say how long the protection from T cells would last.
"We found that pre-existing high levels of T cells, which the body makes when infected with other coronaviruses such as the common cold, can protect against COVID-19 infection," said study author Dr Rhia Kundu. 1/2022).
The study, published in Nature Communications, reports that the internal protein of the SARS-CoV-2 virus targeted by T-cells could offer an alternative target for vaccine makers.
The current COVID-19 vaccine targets a spike protein that mutates regularly. When the spike protein creates variants such as Omicron, it reduces the vaccine's efficacy against symptomatic infections.
"In contrast, the internal proteins targeted by the protective T-cells we identified mutated much less," said Professor Ajit Lalvani, co-author of the study.
"As a result, they are highly conserved among the various SARS-CoV-2 variants, including Omicron. Therefore, a novel vaccine that includes this conserved internal protein will induce a broad protective T-cell response that should protect against the SARS-CoV-variant." 2 now and in the future," he concluded.