The World Health Organization (WHO) has listed Pfizer-BioNTech’s COVID-19 vaccine for emergency use, a critical step that the United Nations health agency said aims to make the vaccine more readily available in developing nations.

In a statement on Thursday, WHO said its validation of the vaccine – the first since the start of the pandemic – “opens the door for countries to expedite their own regulatory approval processes to import and administer the vaccine”.

It will also allow groups, such as UNICEF and the Pan-American Health Organization, “to procure the vaccine for distribution to countries in need”, the WHO said. “This is a very positive step towards ensuring global access to COVID-19 vaccines,” Dr. Mariangela Simao, WHO assistant director-general for access to medicines and health products, said in the statement.

“But I want to emphasize the need for an even greater global effort to achieve enough vaccine supply to meet the needs of priority populations everywhere.” WHO said the Pfizer-BioNTech vaccine met its safety requirements and its benefits outweighed any potential risks.

The vaccine, which must be kept at ultra-low temperatures, is already being administered in several countries, including the United States, Canada, Qatar, Bahrain and Mexico. Human rights groups have raised concerns about richer countries “hoarding” vaccines at the expense of developing nations.

A recent report by Amnesty International found that all of Moderna Inc’s COVID-19 vaccines and 96 percent of Pfizer-BioNtech’s doses had been secured by rich countries, including Canada, the United Kingdom and the US.

“Many countries have seen the vaccine, understandably so, as their way out of this crisis and it’s been a race,” Stephen Cockburn, head of economic and social justice at Amnesty, said this month.

“Rather than work together, we’ve had a ‘me first’ attitude in many countries and there’s been a lack of multilateralism and global coordination in the world.” Africa Centers for Disease Control and Prevention Director John Nkengasong also warned that Africa might not see vaccines until after the second quarter of 2021.

Nkengasong called it a “moral issue” and urged the UN to summon a special session to discuss the ethical and fair distribution of vaccines to avoid “this North-South distrust in respect to vaccines, which is a common good”.

The UN health agency, with the GAVI Vaccine Alliance and the Coalition for Epidemic Preparedness Innovations (CEPI), is spearheading a global effort called COVAX to secure and distribute vaccines to poorer countries, to ensure shots do not go only to wealthy nations.

The WHO-backed COVAX alliance has agreements for nearly two billion doses, with first deliveries due in early 2021. The alliance has been in talks with Pfizer and BioNTech to secure vaccine.