"It would be sad if the rich are given priority for the Covid-19 vaccine. It would be sad if the vaccine becomes property of this or that nation, if it is not universal and for everyone," Francis said at his weekly general audience on Wednesday.

The World Health Organisation (WHO) said on Tuesday that any nation which hoards possible COVID-19 vaccines while excluding others would deepen the pandemic.

WHO chief Tedros Adhanom Ghebreyesus, who has warned against "vaccine nationalism", urged countries to join a global pact by an August 31 deadline to share vaccine hopefuls with developing countries.

More than 150 vaccines are in development, about two dozen are in human studies and a handful are in late-stage trials.

Francis also said it would be a "scandal" if governments doled out pandemic-related bail-out money to only select industries.

He said the criteria for companies to receive public aid should be if they "contribute to the inclusion of people who are normally excluded (from society), to helping the most needy, to the common good and to caring for the environment".

More than 21.9 million people have been reported to be infected by the novel coronavirus globally and 772,647 have died, according to a Reuters tally.

"The pandemic is a crisis and one never exits from a crisis returning to the way it was before," Francis said.

"Either we leave better, or we leave worse. We have to leave better in order to tackle social injustices and environmental degradation."

Australian Associated Press