UNMC experts answer your questions about COVID

There’s no clear-cut definition for when a pandemic starts and ends, and how much of a threat a global outbreak is posing can vary by country.

“It’s somewhat a subjective judgment because it’s not just about the number of cases. It’s about severity and it’s about impact,” says Dr. Michael Ryan, the World Health Organization’s emergencies chief.

In January 2020, WHO designated the virus a global health crisis “of international concern.” A couple months later in March, the United Nations health agency described the outbreak as a “pandemic,” reflecting the fact that the virus had spread to nearly every continent and numerous other health officials were saying it could be described as such.