People who were infected with SARS-CoV-2 more than once are at a higher risk of experiencing long COVID.
Over 64% of Canadian adults have been infected with COVID-19 since the start of the pandemic, according to the Canadian COVID-19 Antibody and Health Survey conducted in June 2023.
Of these, nearly one in five (19%) reported ever experiencing long COVID, which refers to the presence of symptoms three or more months after an infection that could not be explained by anything else.
In the survey, the most commonly reported symptoms were fatigue, brain fog, and shortness of breath, although research suggests long COVID may have over 200 different symptoms.
People with disability or/and one or more chronic conditions before the start of the pandemic were more likely to experience long-haul symptoms, the survey reveals.
The risk of long COVID also increases with every reinfection. Those who had COVID-19 twice were 1.7 times more likely to report the condition than adults infected only once. Meanwhile, having three or more infections raises the risk of long COVID 2.6-fold.
One in four (42.2%) adults who still had long COVID during the time of the survey said the symptoms lasted for one year or more.
The symptoms have changed since the emergence of the Omicron strain in late 2021, with more individuals reporting feeling worse after physical or mental activity, coughing, and fatigue. People infected with Omicron are less likely to report persistent loss of smell or taste and headache.
Long-term symptoms set COVID-19 apart from other respiratory viruses, such as the flu. This may be because COVID-19 affects a wide range of body systems, not limited to the respiratory system, and can cause organ damage.
Less than half (46.9%) of Canadian adults with long-term symptoms discussed them with their healthcare provider. Of those, most (66.4%) said they did not receive adequate treatment or support.
No cure for long COVID
Scientists are now looking for what can help to relieve long COVID, the condition that affects over 65 million people worldwide.
Research suggests vaccination against COVID-19 significantly cuts the risk of developing long-term symptoms or makes them less severe.
A 2023 study found that the type 2 diabetes drug metformin may prevent long-term COVID if taken shortly after symptoms begin.
Another study suggests that taking the antiviral nirmatrelvir (Paxlovid) within the first five days of the infection may also cut the risk of long-term symptoms.
The mixture of certain probiotics and prebiotics may help to reduce fatigue, memory loss, and difficulty in concentration caused by long COVID, according to a recent study published in the Lancet Infectious Diseases.
There is no cure for long-term COVID-19. Therefore, it is crucial to protect yourself from infections by getting a vaccine and practicing good hand hygiene.