Many countries across the globe are beginning to experience a second wave of SARS-CoV-2, the virus responsible for Covid-19. The horrific prospect of two epidemics, the flu and coronavirus, occurring at the same time is now an all too real possibility. Canadian Chief Public Health Officer Theresa Tam stated that “unless protective measures are strengthened the nation is on track for a major resurgence in cases” . European cities are doing exactly that, with many of them re-imposing restrictions on indoor/outdoor gatherings in an attempt to prevent another nationwide lockdown. However, the question remains: what will happen if and when Covid-19’s second wave arises, and how will it interact with the flu.
This raises an interesting question to researchers who are trying to understand the biochemical and cellular factors that give rise to Covid-19’s varying effects on the human body. Scientists at Washington University School of Medicine recently conducted a study analyzing the immunopathology and causes of severe respiratory distress, like influenza and Covid-19. For the most part, these two viruses seem symptomatically similar except for some key molecular differences. For one, individuals with Covid-19 experience a cytokine storm, an aggressive inflammatory reaction to a virus. In humans, this storm typically leads to the deterioration of endothelial cells in the lungs and increases the risk of contracting pneumonia. However, these scientists were intrigued that patients with Covid-19 experienced “profound type I and type II IFN immunosuppression in comparison to influenza patients” . It is believed that this immunosuppression is what leads to significantly high viral counts found in Covid-19 patients, as “IFN receptors are critical to modulating the antiviral immune response” . These two viruses have vastly different underlying pathologies, regardless of the similarity of their visible phenotypes, so doctors need to adopt new protocols to treat each respective patient.
Beyond the molecular scale, these two viruses pose a unique problem for the healthcare industry. There are significant similarities between the typical symptomatic representation of influenza and Covid-19, so distinguishing between the two based solely off of visible symptoms is almost impossible. It is only through the various PCR and saliva tests that scientists are able to definitively differentiate the two from one another.
Now, as the seasonal flu commences, individuals who would otherwise have just treated themselves at home will now go and get tested for COVID-19. An estimated 25 to 50 million Americans are infected annually, and if a significant portion go to get tested, they will put an increased strain on the United States’ already overburdened testing apparatus. At the present moment, United States labs conduct about “800,000 diagnostic tests daily, but various estimates assert that there needs to be 6-10 million tests per day”  In areas where access to these laboratories is limited, this can have significant consequences, preventing individuals from obtaining the necessary testing and contact tracing they need. This, combined with the “mask and isolation fatigue”—exhaustion with lockdowns and significant healthcare precautions—sets the stage for an incredible burden on an already overdrawn healthcare industry.
However, it is not all doom and gloom. An observational study conducted by Professor Benjamin Crowling determined that “influenza transmission [in Hong Kong] declined substantially after the implementation of social distancing measures and changes in population behaviours in late January , with a 44 percent reduction in transmissibility in the community” . The mandated masks, social distancing and handwashing proved to be effective in curtailing viral transmissions as a whole. Moreover, a separate study determined that “transient immune-mediated interference can cause a relatively ubiquitous common cold-like virus to diminish during peak activity of a seasonal virus” . In essence, this means that because of the high infection rate of SARS-CoV-2, the human population’s burst of temporary immunity can protect against more common seasonal viruses like the flu and the common cold when they are most active.
It is important to understand that the only thing people are certain of during this time is uncertainty itself. These aforementioned studies are used to forecast what could happen in the coming months, and all of them can only be right to some degree of certainty. It is important that we, as citizens, remain vigilant to combating this virus, following public health guidelines and amending our personal behaviors for the benefit of the community.
Edited by: Eileen Yang
Illustrated by: Elena Bosak