All the research
Long Covid Learning collects research from scientists worldwide and summarizes the findings to make takeaways more accessible to those outside the research community. Study summaries can be shared as links or images in messages and social media.
Visit “The Research” to navigate by topic or to search by keyword.
Loss of brain “gray matter”
Imaging of the brain before and after Covid infection showed significant loss of brain tissue — even for "mild" cases that did not require hospitalization — in areas responsible for behavioral and emotional response, memory, and more. The reduction in overall cortical gray matter is equivalent to what older adults lose over years of aging.
Imaging of the brain before and after Covid infection showed significant loss of brain tissue — even for "mild" cases that did not require hospitalization — in areas responsible for behavioral and emotional response, memory, and more.
The reduction in overall cortical gray matter is equivalent to what older adults lose over years of aging.
Source: SARS-CoV-2 is associated with changes in brain structure in UK Biobank | Nature
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Toxic proteins in the brain
Covid virus can produce proteins that form deposits that are toxic to nerve cells, like those found with Alzheimer's and Parkinson's diseases. These "amyloid structures" may explain long-lasting neurological symptoms after Covid: memory loss, sensory confusion, severe headaches, brain inflammation, cognitive and psychiatric issues, and even stroke, as well as the risk of neurodegenerative diseases.
Covid virus can produce proteins that form deposits that are toxic to nerve cells, like those found with Alzheimer's and Parkinson's diseases.
These "amyloid structures" may explain long-lasting neurological symptoms after Covid: memory loss, sensory confusion, severe headaches, brain inflammation, cognitive and psychiatric issues, and even stroke, as well as the risk of neurodegenerative diseases.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Similarities to chemotherapy
Studies of the brain after even mild Covid infections show lasting damage to parts of neurons (including their "myelin sheaths") that are essential to cognitive, sensory, and motor function. Similar damage causes the side effects from aggressive chemotherapy, potentially explaining why Long Covid "brain fog" resembles concentration and memory problems suffered by some cancer patients ("chemo-fog").
Studies of the brain after even mild Covid infections show lasting damage to parts of neurons (including their "myelin sheaths") that are essential to cognitive, sensory, and motor function.
Similar damage causes the side effects from aggressive chemotherapy, potentially explaining why Long Covid "brain fog" resembles concentration and memory problems suffered by some cancer patients ("chemo-fog").
Source: Mild respiratory COVID can cause multi-lineage neural cell and myelin dysregulation - ScienceDirect
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Infection can raise the risk of reinfection
Prior infection by some variants is found to decrease rather than increase immune response to later variants in people who were vaccinated. Prior infection by Omicron only poorly increases immune response to later infections by other Omicron variants. This finding opposes the theory that better “hybrid” immunity arises from vaccination paired with infection — infections that also raise the risk of Long Covid.
Prior infection by some variants is found to decrease rather than increase immune response to later variants in people who were vaccinated. Prior infection by Omicron only poorly increases immune response to later infections by other Omicron variants.
This finding opposes the theory that better “hybrid” immunity arises from vaccination paired with infection — infections that also raise the risk of Long Covid.
Source: Immune boosting by B.1.1.529 (Omicron) depends on previous SARS-CoV-2 exposure | Science
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Metabolic issues in the brain
Scans show that specific parts of the brain have significantly lower energy use in individuals with Long Covid. These abnormal scans clearly separate healthy patients from those with Long Covid symptoms, who report loss of smell and taste, memory problems, sleep disorders, chronic pain, and other symptoms weeks or months after the initial infection.
Scans show that specific parts of the brain have significantly lower energy use in individuals with Long Covid.
These abnormal scans clearly separate healthy patients from those with Long Covid symptoms, who report loss of smell and taste, memory problems, sleep disorders, chronic pain, and other symptoms weeks or months after the initial infection.
Source: 18F-FDG brain PET hypometabolism in patients with long COVID | SpringerLink
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Unexplained stillbirths
In a study of 170 women who delivered after a confirmed Covid infection, 50% had placental abnormalities. These were found to be associated with poor pregnancy outcomes, including a significantly higher number of stillbirths (17% vs. 4%) that could not be explained by other risk factors. Babies who survived had lower Apgar scores (a basic measure of the baby's health at birth).
In a study of 170 women who delivered after a confirmed Covid infection, 50% had placental abnormalities.
These were found to be associated with poor pregnancy outcomes, including a significantly higher number of stillbirths (17% vs. 4%) that could not be explained by other risk factors. Babies who survived had lower Apgar scores (a basic measure of the baby's health at birth).
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Psychiatric and brain disease
Covid significantly raises the risk of both psychiatric disorders and neurological diseases such as dementia, brain hemorrhage, stroke, and Parkinson’s. 34% of the 236,379 patients were diagnosed with these illnesses in the months after Covid infection — the first such diagnosis for 13% of them. Researchers note that risks “appear widespread” and “persist up to, and probably beyond, 6 months.”
Covid significantly raises the risk of both psychiatric disorders and neurological diseases such as dementia, brain hemorrhage, stroke, and Parkinson’s.
34% of the 236,379 patients were diagnosed with these illnesses in the months after Covid infection — the first such diagnosis for 13% of them. Researchers note that risks “appear widespread” and “persist up to, and probably beyond, 6 months.”
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Heart function impairment
Magnetic imaging shows that 1 in 5 people with Long Covid have significant heart problems after 6 months, with even higher risk among men. 81% of those with heart function impairment had not been hospitalized with Covid, and 58% of them continued to have heart problems over a year after Covid infection.
Magnetic imaging shows that 1 in 5 people with Long Covid have significant heart problems after 6 months, with even higher risk among men.
81% of those with heart function impairment had not been hospitalized with Covid, and 58% of them continued to have heart problems over a year after Covid infection.
Source: Cardiac impairment in Long Covid 1-year post-SARS-CoV-2 infection | medRxiv
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Liver damage
Covid often causes liver damage, as confirmed by tests on two independent groups of hospitalized Covid patients and autopsy results from a third group. The susceptibility of the liver to damage suggests that the molecular changes leading to liver damage is not only a consequence of severe Covid but may also be present in patients with only mild Covid infections.
Covid often causes liver damage, as confirmed by tests on two independent groups of hospitalized Covid patients and autopsy results from a third group.
The susceptibility of the liver to damage suggests that the molecular changes leading to liver damage is not only a consequence of severe Covid but may also be present in patients with only mild Covid infections.
Source: Molecular consequences of SARS-CoV-2 liver tropism | Nature Metabolism
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Vaccines lower risk only 15%
Vaccination reduces the risk of death by 34% and Long Covid chronic health issues by only 15% in the six months following Covid infection. These risks were 50-75% higher than for those without evidence of infection. Risk reduction was most evident for blood clots (56%) and lung issues (46%), but modest in other organ systems. Long Covid symptoms are similar regardless of vaccination.
Vaccination reduces the risk of death by 34% and Long Covid chronic health issues by only 15% in the six months following Covid infection.
These risks were 50-75% higher than for those without evidence of infection. Risk reduction was most evident for blood clots (56%) and lung issues (46%), but modest in other organ systems. Long Covid symptoms are similar regardless of vaccination.
Source: Long COVID after breakthrough SARS-CoV-2 infection | Nature Medicine
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Serious conditions in kids
After Covid infection, children have twice the risk of acute pulmonary embolisms (blood clots that move to the lungs), venous thromboembolic events (clotting in veins), and myocarditis or cardiomyopathy (inflammation of the heart). Rates of sudden kidney failure and type 1 diabetes are 20-30% higher.
After Covid infection, children have twice the risk of acute pulmonary embolisms (clots moving to the lungs), venous thromboembolic events (clotting in veins), and myocarditis or cardiomyopathy (inflammation of the heart).
Rates of sudden kidney failure and type 1 diabetes are 20-30% higher.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Kidney failure
The risk of acute kidney injury doubles and there are multiple signs of kidney function decline after Covid infection regardless of whether patients were hospitalized.
The risk of acute kidney injury doubles and there are multiple signs of kidney function decline after Covid infection regardless of whether patients were hospitalized.
Source: Kidney Outcomes in Long COVID | American Society of Nephrology (asnjournals.org)
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Brain infections in kids
A children's hospital in the U.S. noticed a 236% increase in rare and dangerous bacterial infections in the brain, many of which were diagnosed during or immediately after Covid infection. A follow-up survey found increases in these infections in 43% of responding U.S. hospitals.
A children's hospital in the U.S. noticed a 236% increase in rare and dangerous bacterial infections in the brain, many of which were diagnosed during or immediately after Covid infection.
A follow-up survey found increases in these infections in 43% of responding U.S. hospitals.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
53% affected months later
In a comprehensive study of almost all Faroe Islands residents infected in the first Covid outbreak, 53% reported symptoms months later. 8.9% reported "severe" long-lasting symptoms, despite less than 5% requiring hospitalization for the initial infection. The most common moderate-to-severe symptoms included fatigue (13%), loss of smell (10%), and loss of taste (7%).
In a comprehensive study of almost all Faroe Islands residents infected in the first Covid outbreak, 53% reported symptoms months later.
8.9% reported "severe" long-lasting symptoms, despite less than 5% requiring hospitalization for the initial infection. The most common moderate-to-severe symptoms included fatigue (13%), loss of smell (10%), and loss of taste (7%).
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Disrupted T cells and cortisol
Those suffering from Long Covid show "uniformly low" levels of cortisol, the body's main stress hormone that controls how the body makes and uses energy, sleep/wake cycles, blood pressure, and more. Long Covid sufferers also had fewer memory immune T cells and more "exhausted" T cells, which play important roles in how the body fights disease (including the dormant diseases that Covid can reactivate).
Those suffering from Long Covid show "uniformly low" levels of cortisol, the body's main stress hormone that controls how the body makes and uses energy, sleep/wake cycles, blood pressure, and more.
Long Covid sufferers also had fewer memory immune T cells and more "exhausted" T cells, which play important roles in how the body fights disease (including the dormant diseases that Covid can reactivate).
Source: Distinguishing features of Long COVID identified through immune profiling | medRxiv
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Brain blood vessel damage
SARS-CoV-2 infects cells lining the brain’s blood vessels, causing high levels of inflammation and damage to vessels and tissues that can lead to an array of cognitive and neurological problems. The virus thrives in these brain-adjacent cells and can use them to disrupt the blood-brain barrier and enter the brain itself.
SARS-CoV-2 infects cells lining the brain’s blood vessels, causing high levels of inflammation and damage to vessels and tissues that can lead to an array of cognitive and neurological problems.
The virus thrives in these brain-adjacent cells and can use them to disrupt the blood-brain barrier and enter the brain itself.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Immune development in babies
Babies were born with reservoirs of SARS-CoV-2 in their intestines months after the mother's infection. The presence of SARS-CoV-2 in a baby's gut may significantly impact the development of the immune system both before and after birth, with the potential for babies to suffer from higher susceptibility to disease and other dangerous outcomes.
Babies were born with reservoirs of SARS-CoV-2 in their intestines months after the mother's infection.
The presence of SARS-CoV-2 in a baby's gut may significantly impact the development of the immune system both before and after birth, with the potential for babies to suffer from higher susceptibility to disease and other dangerous outcomes.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Liver failure in kids
Mild cases of Covid in children can lead to hepatitis and acute liver failure. Biopsies from a previously healthy 3-year-old girl showed immune cells attacking the liver as part of the inflammatory response to SARS-CoV-2 infection, adding further evidence that Covid is responsible for the sharp increase in cases of hepatitis in kids.
Mild cases of Covid in children can lead to hepatitis and acute liver failure.
Biopsies from a previously healthy 3-year-old girl showed immune cells attacking the liver as part of the inflammatory response to SARS-CoV-2 infection, adding further evidence that Covid is responsible for the sharp increase in cases of hepatitis in kids.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
54% after 6 months
54% of those infected with Covid still suffered from symptoms such as brain, lung, heart, cognitive, and a variety of other issues (such as fatigue and low tolerance for exercise) over 6 months after the initial infection. This was the conclusion of a systematic review of 57 studies spanning over 250,000 people globally.
54% of those infected with Covid still suffered from symptoms such as brain, lung, heart, cognitive, and a variety of other issues (such as fatigue and low tolerance for exercise) over 6 months after the initial infection
This was the conclusion of a systematic review of 57 studies spanning over 250,000 people globally.
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
Heart failure and stroke
Even a mild case of Covid significantly increases risk of cardiovascular problems — including heart failure and stroke — for at least a year after infection. Researchers found evidence of this increased risk even for younger, healthier individuals who lacked other risk factors (such as obesity or diabetes) in their study of 5 million medical records.
Even a mild case of Covid significantly increases risk of cardiovascular problems — including heart failure and stroke — for at least a year after infection.
Researchers found evidence of this increased risk even for younger, healthier individuals who lacked other risk factors (such as obesity or diabetes) in their study of 5 million medical records.
Source: Long-term cardiovascular outcomes of COVID-19 | Nature Medicine
Share the research
Follow us on social media to easily share this study and others with your friends, family, colleagues, and communities. Help us raise awareness of the risk Long Covid poses to us all.
