Speaking with the press, the organisation's director-general, Tedros Adhanom Ghebreyesus, said, "Pandemic is not a word to use lightly or carelessly. It is a word that, if misused, can cause unreasonable fear or unjustified acceptance that the fight is over, leading to unnecessary suffering and death."
What does this mean?
As the WHO director-general pointed out, this term is not used lightly. According to the organisation, it is reserved for "the worldwide spread of a new disease."
To determine if an outbreak can be called a pandemic, the organisation looks at the geographic spread of a disease, the severity of illnesses it causes, and its impact on the world.
"WHO has been assessing this outbreak around the clock, and we're deeply concerned both by the alarming levels of spread and severity and by the alarming levels of inaction," Ghebreyesus said while making the declaration.
What is next?
Once an outbreak is officially declared a pandemic, The Conversation reports that this tells governments, agencies and aid organizations worldwide to stop focusing on containment.
Now, everyone has to turn their efforts to mitigation (taking the appropriate steps to reduce the severity of the virus).
The economic, political and societal impacts on a global scale that come with making this formal declaration is why the WHO took its time deliberating.
However, the organisation is hopeful that the COVID-19 pandemic can be controlled.
"We have never before seen a pandemic sparked by a coronavirus. And we have never before seen a pandemic that can be controlled at the same time. We cannot say this loudly enough, or clearly enough, or often enough: All countries can still change the course of this pandemic," the WHO Director-General said.
A little history class
This is not the first time an outbreak has been declared a pandemic. One of the earliest in human history is back in 1580.
Since then, the Centers for Disease Control and Prevention (CDC) says there have been at least four pandemics caused by the influenza in the 19th century and three in the 20th century.
Before the virus, the last one was in 2009 when H1N1 flu killed between 151,700 and 575,400 people worldwide during the first year.
Coronavirus in Africa