Why are there people who don’t get infected with Covid?

One of the questions that many people have asked themselves since the emergence of Covid-19 pandemic es why there are people who seem immune to the disease.

Since then, several theories have emerged, but now a team of scientists has discovered new ones. immune responses which help explain how people who were even in contact with the coronavirus avoid contracting and developing Covid.

Using single-cell sequencing, researchers from the Wellcome Trust Sanger Institute, University College London (UCL) and Imperial College London studied the responses immune against SARS-CoV-2 infection in healthy adult volunteers.

Not all exposed participants developed a Covid-19 infection, allowing the team to uncover unique immune responses associated with resistance to sustained viral infections and illness.

Why are there people who don’t get infected with Covid?

The findings, published in Nature, provide the “most comprehensive timeline” to date on How the body responds to exposure to SARS-CoV-2 or any infectious disease, according to the authors.

The work is part of the international Human Cell Atlas initiative, which is Mapping all cell types in the human body to transform the understanding of health and disease.

The researchers set out to capture immune responses directly from exposure, the Wellcome Trust Sanger Institute reports in a statement.

To do this, at 36 Healthy adult volunteers with no history of Covid They were administered the SARS-CoV-2 virus through the nose.

Monitoring people with the SARS-CoV-2 virus

The researchers conducted a Detailed monitoring of blood and lining of the nosetracking the entire infection as well as immune cell activity prior to infection in 16 volunteers.

The teams then used the single cell sequencing to generate a data set of over 600,000 individual cells.

In all participants, the team discovered previously unreported responses involved in the immediate detection of the virus.

This included the activation of immune cells specialized mucosal cells in the blood and a reduction in inflammatory white blood cells that normally engulf and destroy pathogens.

“Different” immune response to Covid

Individuals who immediately eliminated the virus did not show a typical generalized immune responsebut developed subtle innate immune responses never seen before.

Researchers suggest that high levels of activity in a gene called HLA-DQA2 before exposure also helped people prevent long-term infection.

In contrast, the six individuals who developed sustained SARS-CoV-2 infection exhibited a rapid immune response in the blood, but a slower immune response in the nosewhich allowed the virus to establish itself there.

The researchers also identified common patterns among activated T cell receptors, which recognize and bind to virus-infected cells.

Potential for new therapies against Covid and other diseases

This provides insight into immune cell communication and the potential to develop therapies directed with T cells not only against Covid, but against other diseases.

Rik Lindeboom, now at the Netherlands Cancer Institute, says it was “an incredibly unique opportunity” to see what cancers are like. immune responses when encountering a new pathogenin an environment where factors such as infection time and comorbidities could be controlled.

For Marko Nikolić from UCL, there is now a much greater understanding of the full range of immune responses.

New Covid vaccines?

That could provide a basis for developing potential treatments and vaccines that mimic these natural protective responses.

Sarah Teichmann, lead author of the study and co-founder of the Human Cell Atlas, adds that as this map is built, it will be possible to better identify which of the cells are essential to combat infections and understand why different people respond to the coronavirus in different ways.

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