Why do some people never get Covid-19? Theories, from pushing genetics to cross-immunity – Observer

In the end, few friends It is not the only explanation for those who, more than two years after the start of the Covid-19 pandemic, still have not contracted the coronavirus. If you already have dangerous contacts and you still have not become infected, The answer may lie in the strength of your immune system or in your genetic characteristics.

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This is indicated by several studies that have sought to find out how, after a long time, some have never been infected with SARS-CoV-2 – not even had Covid-19 without developing symptoms. One theory came from Imperial College London, he points out ABC: Who has the Production of higher levels of T cells after contact with a cold coronavirus It will be less likely to be infected with SARS-CoV-2.

T cells are cells of the immune system that retain the properties of an invader (such as a virus or bacteria) to attack in the event of a new contact. SARS-CoV-2 has some characteristics similar to other coronaviruses with which the human body comes into regular contact The immune response to a previous infection may act as a cross-immunity Against the Covid-19 virus.

That’s what Rhea Kondo, the study’s author, explained in the press release for Imperial University of LondonThe researcher emphasized that “exposure to SARS-CoV-2 does not always lead to infection.” It concluded that high levels of pre-existing T cells, which the body creates when infected with other human coronaviruses, such as the common cold, can protect against COVID-19 infection. This may not be enough to protect someone from illness, which is why vaccination and compliance with personal protective measures remain essential: “No one can count on this alone.”.

Another theory is found in genes. Stuart Tange, an immunologist at the Garvan Institute of Medical Research, believes that there will be those who are less likely to contract viral infections because they are infected with the virus. Genetic mutations that act as a natural shield. The ABC remembers that it is nothing new for SARS-CoV-2: There are also people who, due to a genetic mutation, do not have the cellular structures that the AIDS virus uses to infect cells. Therefore, these people are resistant to HIV.

One Queen’s University Study In Belfast, Northern Ireland, he determined that if genes could impair the ability of vulnerable individuals to fight off the virus, they could also be an added advantage. Lindsey Broadbent, the report’s lead author, says she discovered a volunteer in the study They cannot be infected with SARS-CoV-2 because it contains genetic mutations that enhance the immune response against infection.

In the United States, a study is underway to find more definitive answers as to why one person gets infected and another escapes similarly exposed to the virus. Jennifer Nuzzo, a researcher in the Brown University School of Public Health, is leading one such study.

In an interview with NBC, he revealed his theory: “There was an opportunity for that Some people may express a different level of receptors, The types of cells the virus is trying to invade and that people with more of these cells may be more likely to be infected than people with fewer.” In the absence of definitive answers, and as the scientific community explores the topic, a vaccine and individual protection methods remain the best barriers to avoidance. Covid-19 and critical diseases.