Scientists at the University of Manchester have made an important discovery that could explain why some people feel breathless and tired long after recovering from serious viral lung infections like the flu or COVID-19.
In a study using mice, the researchers found long-term damage in the lungs—even after the virus had gone and symptoms had faded.
Many people who have had severe infections with viruses like influenza or SARS-CoV-2 (the virus that causes COVID-19) continue to struggle with breathing and energy for weeks or even months.
Until now, scientists didn’t fully understand what caused these lingering symptoms. This new research, published in the journal Mucosal Immunology, helps explain what might be going on inside the lungs.
The researchers found that a part of the lung called the basement membrane remains damaged after a serious viral infection. This membrane is a thin, supportive layer that helps hold lung cells in place and acts as a barrier. It also helps control how fluids and cells move in and out of the lung tissue. In healthy lungs, this structure supports normal breathing.
To study what happens after an infection, scientists looked at the lungs of mice that had been infected with the flu virus. They used a technique called proteomic mass spectrometry to compare proteins in infected and non-infected mice. Another method, called peptide location fingerprinting, helped the researchers detect small changes and damage in protein structures.
They found that after infection, the basement membrane was not only missing some of its usual proteins but also had structural damage.
This means the membrane didn’t heal properly. The damage made the lungs “leaky,” meaning they couldn’t function as well as before. When viewed under a microscope, the damage appeared patchy—some areas were worse than others.
Interestingly, the scientists noticed that the same kind of basement membrane damage was also found in older mice that had not been infected. This suggests that repeated infections may speed up the aging process in the lungs.
According to the researchers, every time the lungs get inflamed from an infection, some damage may stay behind. Over time, this could make the lungs work less efficiently.
Dr. Alex Eckersley, who helped lead the study, said they were excited about the discovery because it shows a brand-new way to look at the long-term effects of viral infections.
He said that just like aging, serious infections can damage the lungs in a similar way. This could explain why people who have had repeated lung infections might have more trouble breathing as they get older.
Dr. Eckersley hopes that by learning more about how the basement membrane is affected, scientists can find new ways to treat post-viral symptoms. If they can figure out how to repair or protect this part of the lung, they might be able to help people recover faster and avoid long-term breathing problems.
In the future, this research could lead to new medicines aimed at helping the lungs heal better after infections. It also gives doctors and scientists a better understanding of what’s happening in the body long after the flu or COVID-19 has passed.
If you care about lung health, please read studies about marijuana’s effects on lung health, and why some non-smokers get lung disease and some heavy smokers do not.
For more information about health, please see recent studies that olive oil may help you live longer, and vitamin D could help lower the risk of autoimmune diseases.
The study is published in Mucosal Immunology.
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