The COVID-19 pandemic has caused significant morbidity and mortality throughout the world, as well as major social, educational and economic disruptions. There is an urgent global need for effective and safe vaccines. On 31 December 2020, WHO listed the COVID-19 mRNA vaccine BNT162b2 for emergency use, making the Pfizer–BioNTech vaccine the first to receive emergency validation from WHO since the outbreak began a year earlier. The WHO Emergency Use Listing Procedure (EUL) is a risk-based procedure for assessing and listing unlicensed vaccines, therapeutics and in vitro diagnostics with the ultimate aim of expediting the availability of these products to people affected by a public health emergency. BNT162b2, an mRNA vaccine against COVID-19 developed by BioNTech and Pfizer, has been shown to have an efficacy of approximately 95%, based on a median follow-up of two months. The data reviewed by WHO at this time support the conclusion that the known and potential benefits of BNT162b2 outweigh the known and potential risks. As sufficient vaccine supply will not be immediately available to immunize all who could benefit from it, countries are recommended to use the WHO Prioritization Roadmap and the WHO Values Framework as guidance for their prioritization of target groups. As long as vaccine supplies are very limited (stage I in the WHO Prioritization Roadmap), in settings with community transmission, the Roadmap recommends that priority be given initially to health workers at high risk and older people with and without comorbidities. Protecting high-risk health workers has a threefold purpose: (i) to protect the individual health workers; (ii) to protect critical essential services during the COVID-19 pandemic, and (iii) to prevent onward transmission to vulnerable people. Protecting older people will have the greatest public health impact in terms of reducing the number of deaths. As more vaccine becomes available, additional priority groups should be vaccinated as outlined in the WHO Prioritization Roadmap, taking into account national epidemiological data and other relevant considerations.