Covid virus can remain in the lungs for 2 years!

1 of 1

London. A study has shown that SARS-CoV-2, the virus that causes COVID-19, can persist in the lungs of some people for up to 18 months after infection.

The study published in the journal Nature Immunology showed that the persistence of the Covid virus is linked to the failure of innate immunity.

One to two weeks after becoming infected with COVID, the SARS CoV-2 virus is usually undetectable in the upper respiratory tract.

But, some viruses remain in the body in a secret and unknown manner after causing infection. They persist in what is known as a viral reservoir, even if it remains undetected in the upper respiratory tract or blood.

This is the case with HIV, which remains latent in certain immune cells and can reactivate at any time.

This could also be the case for the SARS CoV2 virus that causes COVID-19, said the team at the Institut Pasteur, which first proposed the theory in 2021, and now have pre-clinical studies in a non-human primate. This is confirmed in the model.

To study the persistence of the SARS CoV2 virus, scientists analyzed biological samples from animal models that were infected with the virus.

They found that the amount of virus that persisted in the lungs was lower for the Omicron strain than for the original SARS CoV2 strain.

“We were really surprised to find the virus in some immune cells, alveolar macrophages, after such a long period of time and when routine PCR tests were negative,” said Nicolas Huot, a researcher at the HIV, Inflammation and Persistence Unit of the Institut Pasteur.

“In addition, we cultured these viruses and were able to see that they were still able to replicate, using tools that were developed to study HIV.”

To understand the role of innate immunity in controlling these viral reservoirs, scientists then turned their attention to NK cells.

“The cellular response of innate immunity, which is the body’s first line of defense, has so far been little studied in SARS CoV2 infections,” Müller-Trutwein said.

“Yet it has long been known that NK cells play an important role in controlling viral infections.”

Studies show that in some animals, macrophages infected with SARS CoV2 become resistant to destruction by NK cells. While in others, NK cells are able to adapt to infection and destroy resistant cells.

Innate immunity therefore appears to consistently play a role in the control of the SARS CoV2 virus, the team said.

–IANS

read this also – Click to read the news of your state/city before the newspaper.