Post-COVID: research program, knowledge infrastructure and expertise network

People with post-COVID are at the centre of the Post-COVID programme. The aim is to help them as quickly and effectively as possible and to improve their quality of life.

Post-COVID affects both children and adults. Symptoms are reported more frequently by women than men. The severity of symptoms varies: some people are able to work or attend school, while others are (partially) housebound or bedridden.

It is important that research includes all groups: people of different ages and genders, and people with mild as well as severe symptoms. Post-COVID can manifest itself in multiple ways. A better understanding of these differences will help tailor care to the individual patient.

Although most projects focus on adults, research is also being conducted into children and people who are bedridden.

People with post-COVID can experience severe symptoms that have a major impact on their daily life. Examples of common and most limiting symptoms include:

• Post-exertional malaise (PEM): PEM is a worsening of symptoms after (minimal) physical, cognitive, and/or emotional exertion.
• Postural orthostatic tachycardia syndrome (POTS): POTS is a form of orthostatic intolerance and causes a significant increase in heart rate upon standing, often accompanied by symptoms such as palpitations, fainting, and fatigue.
• Cognitive problems: For example, difficulties with concentration and memory.
• Exhaustion: Severe, persistent fatigue that does not improve with rest.

These symptoms often occur together and can worsen one another. Research into these symptoms is needed to gain a better understanding of their causes and to develop appropriate treatments.

Want to learn more about research into these symptoms? Click on the different ‘Research into …’ buttons.

A biomarker is a measurable indicator in the body that provides information on a disease or condition. This may include, for example, a specific substance in the blood or stool.

Researchers are working to identify biomarkers associated with post-COVID. If reliable biomarkers are found, they could help physicians diagnose post-COVID more accurately in the future. In addition, biomarkers may provide insight into the underlying disease mechanisms and help tailor treatment more effectively to the individual patient.

Want to learn more about research into biomarkers? Click on ‘Research projects’.

Why do some people develop post-COVID while others do not? And what is the risk for people with post-COVID of developing other chronic conditions, such as cardiovascular disease or dementia?

To answer questions like these, researchers study risk factors: characteristics that may increase the likelihood of developing post-COVID or other chronic conditions. These may include factors such as age, sex, ethnicity, and the severity of symptoms.

By gaining a better understanding of these risk factors, it becomes possible to earlier identify who is at increased risk of developing post-COVID. This can help ensure that patients receive support more quickly.

Want to learn more about research into risk factors? Click on ‘Research projects’.

Post-COVID does not affect everyone in the same way. Some people primarily experience extreme fatigue, while others have symptoms such as breathing difficulties, memory problems, or a combination of these. Based on the type of symptoms or the underlying processes in the body that are not functioning properly, people with post-COVID can be grouped into categories, known as subtypes.

By studying these subtypes, physicians may in the future be able to better tailor treatments to specific symptoms or to the underlying biological processes that are disrupted.

Want to learn more about research into subtypes? Click on ‘Research projects’.

The immune system protects your body against pathogens such as viruses and bacteria, and helps you recover when you are ill. There are indications that the immune system may be dysregulated and/or overactive in people with post-COVID. Research into this helps us better understand the role of the immune system in post-COVID.

Research on the immune system focuses on 3 areas:

• Autoantibodies: antibodies that mistakenly attack healthy cells
• Viral persistence: the continued presence of viral particles in the body
• Immune cells and molecules: which immune cells and molecules play a role in post-COVID and how this differs from healthy individuals

Want to learn more about research into the immune system? Click on ‘Research projects’.

To better understand post-COVID, it is important to study processes in the blood, such as blood clotting and inflammatory responses.

Research shows that the coronavirus may cause small blood clots, also known as microclots. Microclots can damage blood vessels. Inflammation and blood clotting may also interact and reinforce each other. This is known as thromboinflammation. This process may contribute to post-COVID symptoms. Research into microclots and thrombosis is important to gain new insights into the causes of post-COVID and to develop potential treatments.

Want to learn more about research into microclots and thrombosis? Click on ‘Research projects’.

Many people with post-COVID experience long-term symptoms such as concentration problems, memory loss, and brain fog. One possible explanation is neuroinflammation: an inflammatory response in the brain.

In research on neuroinflammation, scientists study how the immune system affects brain cells and neural connections. In addition, these inflammatory processes may disrupt blood flow in the brain. Researchers investigate how and where this inflammation develops, what its effects are, and what can be done to address it.

Want to learn more about research into neuroinflammation? Click on ‘Research projects’.

People with post-COVID often experience extreme fatigue, even after minimal exertion. In these studies, researchers focus on mitochondria: the energy-producing structures within our cells.

Mitochondria are responsible for supplying the body with energy. There are indications that mitochondria may function less effectively in people with post-COVID. By studying this, researchers hope to better understand the origin of severe fatigue and how it might be treated.

Want to learn more about research into mitochondria? Click on ‘Research projects’.

The microbiome is the collection of bacteria, viruses, and fungi that live in and on our bodies. Most of these microorganisms are found in the gut. The microbiome plays an important role in our health: it helps with digestion and supports the immune system.

After a COVID-19 infection, the composition of the microbiome, and therefore the balance in the gut, may remain disrupted for an extended period. This disruption may contribute to post-COVID symptoms.

In microbiome research, scientists investigate whether the composition of bacteria, viruses, and fungi is altered in people with post-COVID. They also study the role the microbiome may play in persistent symptoms and how this knowledge could lead to new treatments.

Want to learn more about research into the microbiome? Click on ‘Research projects’.

Other non-pharmacological treatments may play an important role in managing or recovering from post-COVID symptoms.

For example, researchers investigate whether adjusting activities, stimulating brain function, or reducing inflammation in patients can promote recovery. These approaches focus on alleviating symptoms such as fatigue, concentration problems, and pain. The aim is to help patients cope better with their symptoms and improve their quality of life.

Want to learn more about research into other treatments? Click on ‘Research projects’.

Research into medications is important for finding effective treatments for post-COVID. Several studies within the Post-COVID programme are testing different medications. Many of these medications are already used for other diseases or similar symptoms.

Researchers are investigating whether these medications can also help reduce symptoms in post-COVID and improve recovery. The aim is to identify treatments that are both safe and effective for people with post-COVID.

Want to learn more about research into medications? Click on ‘Research projects’.