What It Means Now That the Coronavirus Is a Pandemic
It’s now official: With the novel coronavirus in over 100 countries by mid-March, the World Health Organization declared the outbreak a pandemic. Though the label might seem semantic, the step could help spark more emergency action plans around the globe, bringing with it more disruptions to daily life. Still, questions linger about why the WHO deferred the call for so long, and what prompted the change.
1. What’s the definition of a pandemic?
The technical criteria are when a new infection, against which most people do not have immunity, mushrooms across continents. That’s a bigger threat than an epidemic, which refers to a more constrained spread to a specific country or area. But the dividing line can by fuzzy. The WHO’s Director-General Tedros Adhanom Ghebreyesus stopped short of labeling the outbreak a pandemic at a Feb. 24 press conference, citing the lack of an “uncontained global spread” or “large-scale severe disease or death,” even though about 30 countries had reported cases at the time.
2. What were they looking at here?
In general, the WHO will examine the geographical reach of cases, along with the deadliness of the disease and the effectiveness of containment efforts before declaring a pandemic. In this case, the virus, which causes the pneumonia-like Covid-19 illness, has spread well beyond its original epicenter in the Chinese city of Wuhan. There are aspects of the virus’s spread and transmission that are still not clear, as well as early indicators of slowed or stopped transmission in some places, including China, Singapore, Nepal and Vietnam.
3. Why now?
A declaration is often triggered after efforts to contain the outbreak in specific regions or countries fail. The goal then switches from containment to mitigation -- trying to ease the pain. (On March 10, Centers for Disease Control and Prevention Director Robert Redfield said that the window for fully containing the coronavirus has passed in some areas of the U.S.) The WHO director has expressed frustration with what he described as a lax response to the crisis in some countries, which he didn’t identify. At a briefing on March 11, he signaled that there had been “alarming levels of inaction” and called again for a more aggressive response, saying countries “should double down.” At the same time, cases have proliferated across the globe, with many of them showing more evidence of sustained person-to-person transmission.
4. What does a pandemic designation mean on the ground?
It could spur more countries to roll out higher-level, emergency-grade response plans at local and state levels. The CDC, for example, said there are a range of measures health officials can take if the outbreak spreads widely in the U.S. One major tool is what’s known as social distancing -- finding ways to limit personal interactions where the virus could transmit, such as closing schools or canceling public events. Still, the way the WHO talks about the virus isn’t any sort of legal designation, and precautions were already being deployed in many countries, including a massive quarantine in parts of China, Italy and extended school closings. Australia activated an emergency plan on Feb. 27, although details were sparse, and scores of American universities -- including Harvard -- shifted classes online and asked students not to return to campus after spring break. Shortly after the declaration, U.S. President Donald Trump suspended all travel from continental Europe to the U.S. for 30 days.
5. How does this compare with other recent outbreaks?
The new coronavirus is from the same family as the one that causes severe acute respiratory syndrome (SARS). Its mortality rate appears to be much lower, but its highly contagious nature has led to more deaths in two months than all those recorded in the nine-month SARS epidemic. Another related virus, known as MERS-CoV, that’s been spreading since 2012, has led to death in 34% of the 2,499 cases recorded. Neither of those outbreaks qualified as pandemics, by WHO standards. The last virus that did make the cut as a pandemic was the 2009 outbreak of a new strain of H1N1 flu, or swine flu. It infected an estimated 61 million people in the U.S. alone and may have killed as many as 575,000 people worldwide in the first year it circulated, according to the CDC. Even then, the WHO faced criticism that it had exaggerated the threat. Perhaps one of the most widely cited pandemics was the 1918 flu outbreak, which killed about 5% of those infected, an estimated 50 million people worldwide.
6. What now?
Tedros said the call does not change the WHO’s overall assessment of the threat or its recommendations for what countries should be doing. “All countries can still change the course of this pandemic,” he said in the briefing. “Those with a handful of cases can prevent those cases becoming clusters and those clusters becoming community transmission.” The official declaration did rattle traders who were already on edge, with expectations mounting that the spreading virus will upend global growth.
The Reference Shelf
- The WHO’s official definition of a pandemic and its various phases.
- Bloomberg Opinion’s Therese Raphael explains why the WHO is a frustrating actor.
- A Feb. 27 Bloomberg Q&A blog with public health experts.
- Articles in Nature and New Scientist about using the pandemic label.
- QuickTakes on what you need to know about the coronavirus, early efforts to contain its spread, questions about its transmission, efforts to develop treatments and a vaccine, the meaning of a WHO “global health emergency,” and one on MERS.
- The CDC has a coronavirus web page, and the Journal of the American Medical Association offers advice for clinicians.
--With assistance from John Lauerman.
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