From school closures and lost jobs to devastated industries and millions of lives stolen by the pandemic, its impacts go far beyond individual suffering. It’s time to take this global crisis seriously, and stop it from worsening inequalities around the world and undermining progress on poverty reduction and clean energy goals.
The definition of a pandemic differs from that of an epidemic, with the former focusing on the scale of disease transmission and the latter identifying illness severity and differentiability. Moreover, the threat from pandemics varies over time, owing to both the frequency of pathogen emergence and the nature of its interaction with human populations (e.g., transmissibility, asymptomatic periods, and symptomatology).
At one extreme, some pathogens have high potential to cause global, severe pandemics, including avian influenza viruses and the SARS-causing coronavirus. Other pathogens have moderate potential, with a global risk but not a severe threat, and still others present a limited risk because they do not have efficient transmission between humans or long asymptomatic periods.
Further, many pathogens that have caused pandemics in the past have emerged from animals, and as a result, the majority of new infectious diseases today are zoonotic. Meanwhile, global trends like population growth and urbanization, increasing demand for animal protein, increased travel and connectivity between population centers, climate change, habitat loss, and antibiotic resistance all increase the probability of a pandemic occurrence and reduce the ability of health systems to contain it.
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