Long COVID refers to symptoms and conditions that continue to develop after the initial COVID-19 infection and lasts for at least 2 months.1,2 It is hard to diagnose long COVID as there is no test to determine the symptoms are due to COVID-19.1
At least 10% of those who experienced severe COVID-19 infections develop long COVID, and more than 200 symptoms have been identified with impacts on multiple organ systems.3
Additionally, unvaccinated individuals have a higher risk of developing long COVID compared to those who are vaccinated10. Therefore, it is important to keep up to date with your vaccinations.
The 7 hypotheses on long COVID’s cause:
Viral Persistance
Studies have shown that for some people, SARS-CoV-2 RNA may remain in the body well after the initial infection, resulting in the virus not being fully cleared and potentially causing chronic symptoms to persist.4
Immune Dysregulation
Patients in long COVID may have altered immune system, including T-cells and B-cells.5,6 These cells all play an important role in helping the immune system fight off current and future infections.6
Latent virus reactivation
Viruses that are dormant in patients may reactivate when the immune system is weakened. Challenges to the immune system with long COVID may cause some of these viruses to flare up.4
Autoimmunity
SARS-CoV-2 virus infection may cause our immune system to produce antibodies against our own body, leading to long COVID symptoms such as organ damage or inflammation.7
Microclots
Patients with acute COVID-19 and / or long COVID may develop tiny blood clots known as microclots.8 These clots may lead to blockages in the blood vessels and alter the flow of oxygen and blood to the body.8
Dysfunctional Neurological Signaling
Long COVID may have an impact on the nerve fibres in the patients’ brain.9 This may result in cognitive impairment and affect memory, concentration, and information processing.9
Disruption of the Microbiome
Long COVID’s negative impact on the immune system can disrupt the balance of microorganisms that normally exist throughout the body.4 This disruption may result in inflammation that enables bacteria to enter the body.4