In an experiment tested on mice, the researchers learned that the most serious cases of COVID-19 were the ones that affected the brain.
“Our thinking that it’s more of a respiratory disease is not necessarily true,” said researcher Mukesh Kumar. “Once it infects the brain, it can affect anything because the brain is controlling your lungs, the heart, everything. The brain is a very sensitive organ. It’s the central processor for everything.”
How the body processes infection
The researchers had two groups of mice involved in the study: one group served as a control group and received a saline injection while the other group was infected with COVID-19. The main goal of the study was to see how the virus affected the mice’s organs.
The study revealed that the infection is likely to cause the most severe symptoms when the virus reaches the brain. The researchers explained that the virus has a better chance of directly reaching the brain when it enters the body through the nose, as opposed to the mouth. Once in the brain, it’s difficult for the body to process the infection, and this can lead to serious, long-term health complications.
“The brain is one of the regions where viruses like to hide because it cannot mount the kind of immune response that can clear viruses from other parts of the body,” Kumar said. “That’s why we’re seeing severe disease and all these multiple symptoms, like heart disease, stroke, and all these long-haulers with loss of smell, loss of taste. All of this has to do with the brain rather than with the lungs.”
In the study, the researchers observed a high viral load in the mice’s lungs in the first few days post-infection; however, the lungs stabilized after that initial spike. Nearly one week post-infection, the researchers noted higher traces of the virus in the brain, which is when the mice started to experience the most severe symptoms. The researchers explained that this trajectory mimics what a lot of consumers have experienced with COVID-19 -- improvements after a few days, and then significant, rapid declines.
Though these findings are important in understanding how COVID-19 can affect consumers’ health, the researchers still worry about the long-term impacts and the potentially endless recovery process.
“It’s scary,” said Kumar. “A lot of people think they got COVID and they recovered and now they’re out of the woods. Now I feel like that’s never going to be true. You may never be out of the woods.”