Decoding Long COVID in women: Immunological mechanisms and clinical implications

Millions of people have lingering illnesses following COVID-19 infection, often referred to as "long haulers" or Long-COVID. As COVID-19 continues to reinfect tens of thousands of Canadians and millions of people globally every day, this could result in an explosion of individuals with Long-COVID symptoms. Because each episode further elevates the risk of Long-COVID, reinforcing the urgent clinical and public health need to understand its mechanisms and develop effective interventions. Although the Long-COVID syndrome has yet to be well-defined, prominently reported manifestations include breathlessness, headache, chest pain, abdominal pain, myalgia, fatigue, cognitive problems, anxiety, brain fog, and depression. While it is still unclear how many people develop long-term symptoms following COVID-19 infection, some cohorts report that between 10% and 30% of infected individuals experience symptoms for months, and some for years. Unfortunately, we do not yet know why women are more likely to develop long-term complications and lingering illnesses than men. With an already established platform and collaborations in place, we have studied more than 100 Long-COVID patients compared to the same number of recovered patients who lack any long-term complications. In particular, we focused on those with chronic fatigue syndrome as the most debilitating form of Long-COVID. We have discovered a wide range of immunological changes in these patients. Specifically, we observed that the odds of developing Long-COVID are three times higher in women than in men. We plan to build on our novel discoveries to understand why women are more susceptible to Long-COVID and how this can be prevented or treated. In doing so, we will address one of the most important research areas concerning Long-COVID in women, with potential therapeutic implications.