The World Health Organization said Friday it has signed a purchase agreement for up to 40 million doses of the coronavirus vaccine developed by U.S. pharmaceutical giant Pfizer Inc. as part of its initiative to provide global equitable access to COVID-19 vaccines.

Between the anticipated supply agreements for the Pfizer vaccine and ongoing work to approve an AstraZeneca/Oxford vaccine candidate, the U.N. health body expects to begin delivering COVID-19 vaccines by late February under an allocation framework designed to ensure access for low- and middle-income countries, the WHO said in a statement.

Pfizer headquarters in New York City. (Kyodo)

The Pfizer vaccine, jointly developed with German partner BioNTech SE, was the first vaccine to receive emergency use validation from the WHO since the outbreak of the novel coronavirus began.

Under an existing agreement, nearly 150 million doses of the AstraZeneca/Oxford vaccine candidate are ready to be shipped out to countries in need upon completion of the WHO's prequalification process to confirm the vaccine's safety and efficacy.

Earlier this week, WHO Director General Tedros Ghebreyesus had criticized vaccine manufacturers for seeking profit by enabling wealthier countries to buy up the available supply of vaccines.