Pfizer and BioNTech's Covid-19 vaccine candidate and is "reviewing it for possible listing for emergency use."A WHO emergency use listing would allow countries to authorize vaccine for national emergency use and could open the door to international supplies of the vaccine through global procurers, WHO stated to Reuters.WHO's comments come after Britain gave the vaccine approval for emergency use on Wednesday, jumping ahead of the United States and Europe to become the first country to formally endorse a jab.Britain's Medicines and Healthcare products Regulatory Agency (MHRA) granted emergency use approval to the Pfizer-BioNTech vaccine, which they say is 95% effective in preventing illness, in record time - just 23 days since Pfizer.