COVID-19 Linked to Unique Brain Impacts Compared to Flu

Tulane study finds COVID-19 causes persistent brain inflammation and small vessel damage, unlike influenza.

Published on Feb. 25, 2026

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New research from Tulane University suggests the long-term impacts of COVID-19 and the flu on the brain differ significantly. While both viruses can cause lasting lung damage, COVID-19 is uniquely associated with persistent brain inflammation and injury to small blood vessels, even after the virus is no longer detectable. These findings may help explain the prevalence of neurological symptoms like brain fog, fatigue, and mood changes in individuals experiencing long COVID.

Why it matters

Understanding the distinct long-term effects of COVID-19 on the brain compared to other respiratory viruses like the flu is crucial for developing effective treatment and management strategies for the lingering neurological symptoms experienced by some COVID-19 patients.

The details

Researchers utilized a mouse model to investigate the effects of both COVID-19 and influenza, examining lung and brain tissue after the infection had cleared. In the lungs, both viruses exhibited similar patterns of damage, with immune cells remaining active longer than expected and an increase in collagen, a protein associated with scarring. However, the crucial distinction emerged in the brain. While neither virus was detected within the brain tissue itself, mice infected with COVID-19 displayed signs of ongoing brain inflammation and evidence of small hemorrhages, which were not observed in mice infected with influenza. Further analysis revealed disruptions in the signaling pathways regulating serotonin and dopamine, neurochemicals vital for mood, cognition, and energy levels. These disruptions were significantly more pronounced in the brains of mice infected with COVID-19 compared to those infected with influenza.

  • The study was published on February 25, 2026.

The players

Dr. Xuebin Qin

Professor of microbiology and immunology at the Tulane National Biomedical Research Center and the lead author of the study.

Tulane University

The institution where the research was conducted.

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What they’re saying

“Influenza and COVID-19 affect large populations worldwide and carry a significant public health toll, yet the mechanisms behind their long-term effects remain poorly understood.”

— Dr. Xuebin Qin, Professor of microbiology and immunology (Frontiers in Immunology)

“Face to the persistence of symptoms that complicate the recovery of some, it is essential to understand their causes in order to reduce the long-term consequences on health.”

— The researchers (Frontiers in Immunology)

What’s next

Researchers emphasize the importance of further investigation into the long-term neurological effects of SARS-CoV-2 infection to develop effective treatment and management strategies for the lingering symptoms of long COVID.

The takeaway

The distinct long-term brain impacts of COVID-19 compared to the flu, including persistent inflammation and small vessel damage, may help explain the prevalence of neurological symptoms in long COVID patients and highlight the need for tailored treatment approaches.