Within weeks, the World Health Organization(WHO) declared it the first pandemic since 1968.

This is the first pandemic that can be controlled, Tedros said in a tweet Wednesday.

The 2009 pandemic marked the first pandemic during which influenza antivirals were available for global use.

It's also the first pandemic for which there's been global activism and the very rapid development of treatments.

H1N1 swine flu is still spreading globally, having caused the first pandemic of the 21st century.

The country's first pandemic plan was published in 1997, the same year that the World Health Organisation produced its own pandemic preparedness plan.

The new H1N1 influenza virus has caused the first pandemic of the 21st century, according to the World Health Organisation.

H1N1 flu, first identified in March, spread globally in a matter of weeks to cause the first pandemic of the 21st century.

Chan said last week it would take another six to 12 months for the first pandemic in more than 40 years to run its course.