You may have heard the quote, “We have met the enemy and he is us.”

In 1971, Walt Kelly wrote the quote in a strip of his comic “Pogo.” The strip was on Earth Day, and it was about pollution, suggesting that humans are sometimes their own worst enemy. The quote stems from a historical one from the War of 1812: “We have met the enemy and they are ours.”

New research reveals that COVID-19, the disease caused by the SARS-CoV-2 virus, is a disease that turns our body against us.

In a recent study, scientists at the National Institutes of Health discovered damage in the brains of patients who succumbed after COVID-19. This may be surprising to some of you who thought COVID-19 was a respiratory infection. But consider some of the symptoms observed during and after COVID infection — dizziness, fatigue, delirium, the loss of smell and the ability to taste, neurological issues, headache and even strokes. This sounds like more than a respiratory infection.

In patients who died, researchers found damage to small blood vessels in the brain called microvasculature that resulted in leaky and thinned blood vessels. In most of these cases, there was not just virus found at these damaged brain sites — they also found immune cells.

Remember that our bodies respond to infection by activating our immune systems to create an inflammatory response. Most times this helps control the infection we’re experiencing. But sometimes, the inflammatory response gets out of control and instead of helping with the infection, it creates more tissue damage.

This becomes an additional challenge for our bodies to overcome as we try to recover from the infection. This can even occur in areas of the body where the virus is not present. In COVID-19 cases, this damage has been observed in the kidney, the heart and yes, even the brain.

This study examined about 20 patients between the ages of 5 and 73 who had died after COVID-19 infections. The scientists took images of these patients’ brains using a special powerful MRI. The scientists were interested in looking at the brain stem, which controls important functions like breathing, heart rate, blood pressure and the olfactory bulb, the area responsible for our ability to smell and taste.

The MRI images revealed bright areas, which indicated inflammation and dark spots, that showed bleeding from nearby blood vessels. Additional microscopic examination revealed proteins from the blood were leaking from small blood vessels, which may have caused the inflammation at these brain sites. This type of damage is similar to what is seen in people who suffer strokes.

Understanding the reason for tissue damage could help us control or treat this devastating disease and save lives. Because we’re realizing that some of the effects of COVID disease may linger for years or even a lifetime, new interventions could help those recovering from neurological issues, heart problems or other long-term medical complications.

Medical Discovery News is hosted by professors Norbert Herzog at Quinnipiac University, and David Niesel of the University of Texas Medical Branch. Learn more at

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(1) comment

Bailey Jones

This is an important reminder that not all COVID patients fully recover from the disease. 50-80% of COVID patients are still experiencing symptoms three months later, and as many as 10% are still experiencing symptoms a year later. Some suffer permanent damage to their lungs, heart, kidneys, or brains. Get yourself vaccinated and avoid a lifetime of pain.

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