summary: COVID-19-related cognitive impairment is linked to the protein IL-1β. Researchers found that vaccination can reduce brain inflammation and memory loss in rodent models, suggesting that vaccination may reduce the risk of long-term brain disruption from COVID. Further studies are needed to confirm these findings in humans.
Key Facts:
- IL-1β protein: Associated with cognitive impairment and reduced neurogenesis.
- Benefits of vaccination: Reduces brain inflammation and cognitive symptoms.
- research resultMemory loss and effects on brain function were reduced in vaccinated models.
sauce: University of Western Ontario
Since the COVID-19 pandemic began, between 10 and 30 percent of the general population have experienced some kind of virus-induced cognitive impairment, including difficulty concentrating, brain confusion, and memory loss.
This allowed the team of researchers to investigate the mechanisms behind this phenomenon and successfully identify specific proteins that appear to be causing these cognitive changes.
A new study has been published. Nature Immunology, The study, led by researchers at Western Washington University School of Medicine in St. Louis, Missouri, also explored how vaccination may help reduce the effects of memory loss after COVID-19 infection.
The research team, including Professor Robin Klein of the Schulich College of Medicine and Dentistry, who moved to Western University from the University of Washington, used rodent models to better understand how COVID-19 affects cognitive impairment.
“We looked closely at the brain during acute infection and after recovery to understand what’s unusual about the different immune cells that are coming into the brain and the effect they have on neurons,” said Klein, who is a Canada Distinguished Investigator in Neurovirology and Neuroimmunology.
Klein said he was concerned that reports of cognitive impairment early in the pandemic led researchers to wonder whether the virus was invading the central nervous system.
Klein’s previous work had looked at viruses that invade the brain.
“We previously showed that the virus was not detectable in the human or hamster brain, and now our study shows that the virus does not invade the central nervous system,” Klein said. This finding implies that there are other mechanisms by which the virus causes cognitive impairment.
The research team determined that SARS-CoV-2 infection increases brain levels of interleukin-1 beta (IL-1β), a cytokine protein that affects the immune system. They observed that models with elevated levels of IL-1β exhibited impaired neurogenesis, the process by which new neurons are formed in the brain, as well as memory loss.
Vaccination reduces cognitive symptoms
The research team concluded that IL-1β is one of the possible mechanisms underlying SARS-CoV-2-induced cognitive impairment and wondered whether this could be prevented by vaccination.
The researchers then looked at how the vaccinated models were affected and found a promising correlation between vaccination and reduced memory loss and other cognitive impairments.
The researchers showed that prior vaccination reduced brain inflammation and lowered levels of IL-1β, resulting in less impact on memory and brain function in vaccinated models.
Klein said much more research is needed to fully understand how the vaccination achieves this result and whether it applies to humans.
“We know there’s anecdotal evidence that vaccinated humans are at much lower risk of developing long-term brain disruptions from COVID-19,” Klein said.
Klein stressed that because the vaccine used in this study is different from the vaccines available for humans, more research needs to be done to further explore the link between vaccination and reduced long-term COVID effects.
“We know that if you get vaccinated, your inflammation is significantly reduced,” Klein said.
She added that vaccination is not about preventing infection altogether, but about reducing the risk of its effects – for example, the vaccine can prevent the onset of severe pneumonia, but it does not prevent pneumonia entirely.
The same is likely true for cognitive effects.
“People need to understand that about the vaccine,” Klein said, “They need to know what it can and can’t do.”
About this memory and COVID-19 research news
author: Cynthia Fazio
sauce: University of Western Ontario
contact: Cynthia Fazio – University of Western Ontario
image: Image courtesy of Neuroscience News
Original Research: The access is closed.
“Vaccination reduces central nervous system IL-1β and memory impairment after COVID-19 in mice” Robin Klein et al. Nature Immunology
Abstract
Vaccination reduces central nervous system IL-1β and memory impairment after COVID-19 in mice
Up to 25% of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience post-acute cognitive sequelae.
Millions of cases of memory impairment due to coronavirus disease 2019 (COVID-19) are accumulating worldwide, but the underlying mechanisms and how vaccination might reduce the risk are unclear. Interleukin-1 (IL-1), a key component of the innate immune defense against SARS-CoV-2 infection, is increased in the hippocampus of COVID-19 patients.
Here, we show that intranasal infection of C57BL/6J mice with SARS-CoV-2 beta mutants leads to central nervous system infiltration of Ly6C.Hello Activation of monocytes and microglial cells.
Thus, SARS-CoV-2, unlike H1N1 influenza virus, elevates levels of IL-1β in the brain and induces sustained IL-1R1-mediated
Loss of hippocampal neurogenesis promotes post-acute cognitive impairment. Vaccination with a low dose of adenoviral vector spike protein prevents hippocampal IL-1β production, loss of neurogenesis, and subsequent memory impairment during acute SARS-CoV-2 infection.
Our study identified IL-1β as one of the potential mechanisms driving SARS-CoV-2-induced cognitive impairment in a novel mouse model that was prevented by vaccination.