Almost one year since the coronavirus outbreak was declared a pandemic, the World Health Organization (WHO) clarified on Monday that it did use the "highest level of alarm" to urge responses from all countries in early 2020.

Asked at Monday's press conference whether the organization should have used the word "pandemic" sooner, Maria Van Kerkhove, the WHO's technical lead on COVID-19, said that the WHO announced a Public Health Emergency of International Concern as early as January 30 last year.

She said that the announcement was indeed the highest level of alarm, or "the highest level that we can under international law."

On January 30, 2020, the WHO declared the outbreak, later named COVID-19, as a Public Health Emergency of International Concern, following two days of discussion by a team of international experts.

Michael Ryan, executive director of the WHO Health Emergencies Program, told the press conference that this level of action was the "highest possible" under common agreement between WHO member states.

He added that there is a solemn legal agreement between 194 WHO members, reached in 2005 when they came together and agreed on what would represent the highest level of alert for global public health emergencies.

"That is an agreement between all member states on this planet, who agreed in law, that this would represent the trigger to collective action in response for containment," he said.

"Maybe we need to shout louder," said Ryan, "But maybe some people need hearing aids."

Ryan also noted in the press briefing that the UN health agency advises against using vaccine certification as a condition for travel since "vaccination is just not available enough around the world and is not available certainly on an equitable basis."

The strategy might be unfair to people who cannot be vaccinated for certain reasons and that requiring vaccine passports might allow "inequity and unfairness be further branded into the system," he added.

(With input from agencies)