Long-Term Effects of COVID-19

The majority of individuals who contract COVID-19 recover within a short period of time without any lingering health problems. However, some people experience long-term health complications despite the mild symptoms during the infection¹. 

Research into long-term COVID-19 effects is still in its early stages as we do not yet have a complete understanding of what it is and what it isn’t. Still, there are a few commonly reported symptoms by patients, namely extreme fatigue, shortness of breath and joint pain².  

What is long-term COVID-19?

Long covid, also known as post-acute COVID-19, is an umbrella term for a collection of lingering health problems that continue or develop after acute COVID-19. Experiencing symptoms 4-12 weeks after contracting coronavirus is termed ongoing symptomatic COVID-19. If the symptoms continue or worsen after 12 weeks of acute COVID-19, it is classified as post-covid syndrome. 

While a conclusive definition is yet to be agreed upon for long-Covid, there are common symptoms that act as potential markers for post-Covid syndrome. The most frequently reported symptoms of long-term COVID-19 include neurological complications, cardiovascular effects, pulmonary impediments and a change in sense of smell. The symptoms categorized by major organ system includes²:

• General symptoms: extreme fatigue, insomnia, unordinary mood swings, joint pain;
• Lungs: shortness of breath, chest pain, prolonged dry cough;
• Nervous system: memory and concentration difficulties (“brain fog”), headache, change in sense of smell;
• Cardiovascular: heart palpitations;
• Gastrointestinal: diarrhea, abdominal pain.

Some individuals predominantly experience respiratory symptoms, namely cough and shortness of breath, and fatigue, while others suffer multi-system effects. These complications affect multiple parts of the body including the brain, gut and cardiovascular system³. 

What causes long-term COVID-19?

It is still unclear why patients experience long-term symptoms and what predisposes some individuals over others to developing them. The majority of experts argue that these long-term effects are caused by a robust inflammatory response – a response in which the immune system goes haywire – in some individuals. 

This immense inflammation is associated with blood clots in the lungs, heart and brain, which may lead to blood vessel damage and subsequent development of long-term health complications⁴. In other words, long-term COVID-19 could be classified as a self-destructive, autoimmune disease. 

Although this hypothesis seems promising, there are no conclusive answers. Other studies have indicated that even after  COVID-19, fragments of the virus remain in the bloodstream and continue to disrupt different functions in the body in various ways.

Alternative hypotheses suggest that post-covid syndrome could be attributed to multiple disorders combined into one, meaning that it is unlikely that there is one, simple, universally applicable explanation for the long-term effects.  

Who is at risk?

Surveys have indicated that over 1 one in 10 people who had COVID-19 continue to develop ongoing health complications. While there is increasing clarity on the incidence of long-term covid, we are still in the early stages of categorizing which individuals are at greatest risk, and why it only impacts some people and not others. 

There is conflicting evidence on the relationship between acute infection severity and the incidence of long-term COVID-19 symptoms. Some research has indicated that individuals who experienced long-term effects had a moderate-severe case of COVID-19, while other research showed that they were asymptomatic or had only a mild infection^1,5.

Studies have suggested long-term COVID-19 becomes increasingly likely with age. Statistics indicated that 10% of below 50-year-olds suffered from long-term Covid, while the incidence increased to 22% for individuals above 70³. Being female, having a high BMI (body mass index) and suffering from a pre-covid respiratory condition were also shown to be potential risk factors for lingering health problems⁶. Still, many ambiguities remain. 

Can the vaccine help reduce the risk of long-term Covid?

It is commonly known that being fully vaccinated against COVID-19 reduces the risk of developing severe symptoms during acute infection. However, research is shedding light on its additional role in lessening the incidence of long-term Covid. 11% of unvaccinated individuals developed ongoing symptoms, while only 5% of fully vaccinated people experienced long-term Covid effects⁷. 

However, the data is highly inconsistent and varies between studies; more research is required to confidently conclude the precise effectiveness of the jab in preventing long-term Covid. What we can be certain about, though, is that Covid vaccines are the most effective known method of reducing viral spread, while also reducing the risk of infection severity.