Israel assured supplies of the vaccine from Pfizer Inc. and BioNTech SE by agreeing to pay a premium and to share countrywide data in what amounts to a large-scale effectiveness study. The U.S., as part of its multibillion-dollar Operation Warp Speed program hastening the development of Covid vaccines, used wartime powers to require manufacturers to fill massive U.S. government orders first, amounting to a de facto ban on vaccine exports initially. The U.K. was the first country to authorize a Covid inoculation for emergency use apart from China and Russia, which deployed domestically developed vaccines before they’d undergone full testing. The EU was slower than Israel or the U.S. to lock down supplies, but faster than most. As inoculations were being developed, a number of wealthy countries signed contracts securing doses from a variety of companies. When multiple vaccines proved winners, some countries wound up with enough promised doses to cover their populations several times, leading to complaints of hoarding.