Long Covid - 2022 Warning

The initial emergency of Covid may feel like it's over, but millions of people are still suffering from ongoing symptoms known as long Covid. So are we any closer to understanding the causes of this sometimes debilitating condition or to finding the best way of treating it?

Most people who catch Covid don't become severely ill and appear to get better relatively quickly. We do not know if there are any long term or long-lasting health effects, such as a lower life expectancy, reduced immune system response to other sickness. We are all guinea pigs, so to speak, and only time will tell what the long term effects of having Covid, or of having Covid more than once, are. 

Some people have long-term problems after recovering from the original infection - even if they weren't very ill in the first place.

What are long Covid symptoms?

Long Covid isn't fully understood, and there's no internationally-agreed definition - so estimates of how common it is, or what the main symptoms are, vary. These can be defined as symptoms that continue for more than 3 to 4 months which cannot be explained by another cause.

These can include:

• extreme tiredness
• shortness of breath, chest pain or tightness
• problems with memory and concentration ("brain fog")
• changes to taste and smell
• joint pain

This pattern will be familiar to many with long Covid. The core experience of long Covid revolves around three principal symptoms: fatigue, brain fog and muscle pain. But there is a long list of rarer symptoms covering almost every bodily function ranging from digestive problems to night sweats and depression to hair loss.

But patient surveys suggest a range of other symptoms may also be present, including gut problems, insomnia and vision changes. It is crucial to remember these symptoms can have other causes too. There's a lot of research investigating the potential long-term impact of coronavirus.

One study suggests Covid may affect the brain, with a slight shrinkage in size visible after infection.

Another suggests some people with long Covid have lung abnormalities.

But the significance of these changes and whether they are permanent is unknown. And the severity of problems also varies enormously. Some people will have no issues continuing with their day-to-day lives, while others may struggle.

The UK Office for National Statistics says one in 40 people have symptoms that last at least three months after an infection. Around 1.5 million people in the UK say they have long Covid symptoms with growing numbers (685,000) saying their long Covid has lasted longer than a year.

"This is a picture that we're seeing more and more," Dr David Strain, from the NHS long Covid taskforce and the University of Exeter, told me.

The likely causes of long Covid

It seems remarkable that a viral infection, even one that was brief and mild, can lead to debilitating symptoms that, for some people, can last for years. There is no single unifying cause of all long Covid, but scientists are focusing on four main areas:

Blood-clots and damage to small blood vessels (micro-clotting)

A disturbed immune system

People are still infected with the coronavirus

Impaired metabolism

Micro-clots: Some symptoms of long Covid could be down to tiny clots blocking up the smallest blood vessels in our bodies, called capillaries. Our major arteries and veins are like motorways up and down our body, but capillaries do the actual job of getting oxygen and nutrients to the individual cells of our bodies. Crucially, capillaries also clear away the waste products of our metabolism. Blocked capillaries could lead to cells becoming rapidly distressed.

"That would account for why some people start the day feeling great because the body's had time to replenish itself, but very, very quickly, they become exhausted," says Dr Strain. It could also account for fatigue that lasts for days after strenuous activity as "those toxins build up and they're just not clearing at the normal rate," he says.

Research has also shown the brain can shrink by between 0.2% and 2% even after mild infection so unrepaired damage is a potential cause of symptoms like brain fog.

Immune system: Scientists have also reported changes in the immune system of people with long Covid. Inflammation is part of the body's normal response to infection or injury, but proteins in the blood suggest excessive inflammation in long Covid which could be driving some symptoms.

Meanwhile, antibodies that normally attack foreign invaders have been shown to stick to the body's own cells in long Covid. Autoantibodies are antibodies that mistakenly target and react with a person's own tissues or organs. These could cause different symptoms depending on where they bind, explains Prof Chris Brightling, from the University of Leicester: "Those with muscle pain and weakness might have an autoimmune problem related to muscles, those with an affected heart rhythm might have autoantibodies to the heart tissue."

Persistent infection: There is also debate about whether the virus is fully kicked out of the body in some with long Covid. The infection starts in the lungs and airways, but the virus is able to infect other parts of the body too. The idea is that the virus takes up residence elsewhere in the body, most likely the in gut which is already teeming with microbial life. "It is just leaking enough virus into the blood that every so often you are back to the beginning again, you are experiencing that flu-like illness and you are exhausted for no apparent reason," says Dr Strain.

Mitochondrial damage: Another concept centres around the body's ability to harness energy, possibly due to abnormalities in the mitochondria. Mitochondria, which are in nearly every cell of our body, are like minute power stations that convert the energy from food into a form usable by the body. "There are people suggesting that the virus itself makes those mitochondria go dormant, which is why we run out of energy much quicker in the fatigue and in the brain fog," says Dr Strain.

How will I know I have long Covid?

There is currently no standard test. People suspected of having it are often  checked for other issues like diabetes, thyroid function and iron deficiency first, before being offered a long Covid diagnosis.

A blood test could become available in the future.

What causes long Covid?

We don't know. It could be that the initial infection sends some people's immune systems into overdrive, meaning they attack not just the virus but their own organs.

The virus entering and damaging our cells might explain some symptoms like a loss of smell and taste, while damage to blood vessels could, for example, contribute to heart problems. It is likely several different things are going on in different people, causing a wide range of problems.

What about children?

Children can also develop long Covid. A team of researchers investigated more than 200,000 positive cases among 11 to 17-year-olds in the UK between September 2020 and March 2021. They estimated that between 4,000 and 32,000 were still experiencing symptoms 15 weeks later. We don't know how severe the symptoms were, although there was little evidence that children were left bedridden or unable to attend school.

However, researchers stress the risk to young people is "not trivial", and say it is vital that children get the right medical support.

What treatments are available?

Currently there are no proven drug treatments, with the main focus on managing symptoms and gradually increasing activity where possible. Studies on how best to improve the lives of people with long Covid are continuing.

Can the vaccine help?

Some reports suggest people who have been vaccinated are less likely to have long Covid. Vaccines help stop people contracting the virus in the first place - but infections can still occur, particularly when immunity starts to wane. Their main job is to prevent people getting very sick with Covid. They may also improve Covid symptoms, either immediately or over several weeks. And there is some evidence that jabs may help prevent infections "turning into" long Covid.

What should you have learnt from this article: one very important thing: YOU DO NOT WANT TO GET COVID - EVEN IF YOU HAVE HAD ALL YOUR VACCINATION SHOTS. IF YOU HAVE ALREADY HAD COVID, YOU DO NOT WANT TO GET IT AGAIN. We do not know whether or not getting covid will harm us long term. For some people their health problems that seemingly originated with a Covid infection, or that were made worse by Covid infection, never leave them. 

So, keep your FFP2 and N95 masks on in indoor places where Covid is likely to be circulating. Limit your exposure. Don't stop protecting yourself because the government says it's OK to stop wearing masks, etc. The government knows it won't be re-elected if it doesn't get the economy moving again.