Study Finds Spike Mutations Help COVID Infect the Brain

Scientists announced they have found a mutation in the COVID-19 virus that plays a role in its capacity to infect a person’s central nervous system and brain.
They said the study, published in Nature Microbiology, could shed more light on “long COVID,” or symptoms persisting for weeks or months after an infection.
They found that the “spike protein,” or the outer portion of the virus that allows it to penetrate into cells, has a series of mutations that allowed it to infect the brains of mice involved in their study.
Changes in the virus’s spike protein were required for it to travel from the lung to the brain, Hultquist said, adding that the process could be a “critical regulator of whether or not the virus gets into the brain.”
“In the lung, the spike protein looked very similar to the virus used to infect the mice,” the release said. “In the brain, however, most viruses had a deletion or mutation in a critical region of spike that dictates how it enters a cell. When viruses with this deletion were used to directly infect the brains of mice, it was largely repaired when it traveled to the lungs.”
Whether so-called long COVID is caused by the spike protein’s ability to directly infect brain cells is not clear, the researchers said.
“It’s still not known if long COVID is caused by direct infection of cells in the brain or due to some adverse immune response that persists beyond the infection,” Hultquist stated. “If it is caused by infection of cells in the central nervous system, our study suggests there may be specific treatments that could work better than others in clearing the virus from this compartment.”
Their finding could have “large implications” for treating long COVID and neurological symptoms reported by COVID-19 sufferers, he said.
According to the Sept. 9 release, funding for the study was provided by the U.S. National Institutes of Health, the Department of Defense, and Northwestern University.
“We know of many other viruses that unleash a similar cytokine storm in response to infection, but without causing blood clotting activity like we see with COVID,” Dr. Warner Greene, senior investigator with the University of California–San Francisco, said in a statement.
The U.S. Food and Drug Administration (FDA) late last month said it updated the COVID-19 vaccine, adding that the shots will target newer strains of the virus. The CDC also has recommended the fall’s shot for everyone age 6 months and older.