‘Brain fog’: Alzheimer’s-like changes found in COVID patients’ brains

FILE PHOTO: A medical staff administers the Pfizer-BioNTech COVID-19 vaccine to a woman at a coronavirus disease (COVID-19) vaccination center in Neuilly-sur-Seine, France, February 19, 2021. REUTERS/Sarah Meyssonnier

People who die of severe COVID-19 have brain abnormalities that resemble changes seen in Alzheimer’s disease – accumulation of a protein called tau inside brain cells, and abnormal amounts of the protein beta-amyloid that accumulates into amyloid plaques – small studies have found.

At Columbia University, Dr. Andrew Marks and colleagues studied the brains of 10 COVID-19 patients and found defects in proteins called ryanodine receptors that control the passage of calcium into cells.

In Alzheimer’s disease, defective ryanodine receptors are linked to accumulation of tau into so-called neurofibrillary tangles. These tangles were present in high levels in the COVID-19 patients’ brains, the Columbia team reported on Thursday in Alzheimer’s & Dementia. Other research teams have looked for – and found – abnormal amyloid levels in brains of COVID-19 patients, according to reports posted online ahead of peer review on bioRxiv and on The Lancet’s preprint server.

In all the studies, patients had experienced the most severe forms of COVID-19. If similar changes are occurring in the brains of patients with milder illness, that might help explain the “brain fog” associated with long COVID, Marks said.

Patients with severe COVID-19 might be at higher risk for dementia later in life, but it is too soon to know, he added. His advice: Get a booster vaccine and avoid the virus. “If you get COVID-19, you probably won’t die, but we still don’t know a lot about the long-term effects.”

Flu shot, mRNA COVID-19 booster safe together

Seniors can safely get the high-dose flu vaccine and an mRNA COVID-19 booster dose at the same time, a new study confirms.

The study involved 306 participants, all older than 65, randomly assigned either to receive Sanofi’s Fluzone High-Dose Quadrivalent influenza vaccine and a third shot of Moderna’s mRNA vaccine at the same time, or either of the vaccines alone.

Blood samples obtained before and 21 days after vaccination showed that giving the two vaccines together did not affect the resulting immune response, with similar antibody levels generated in participants in each of the three groups, according to a report published on Tuesday in The Lancet Respiratory Medicine.

A spokesperson for Sanofi said combined administration of the COVID-19 and influenza vaccines “did not raise any safety concerns and the study team is continuing to follow study participants through 6 months after vaccination.”