The United States will start sharing its stockpile of AstraZeneca’s COVID-19 vaccine with other countries, the Biden administration said on April 26. The United States plans to share all the doses it has, provided they pass safety reviews. As many as 60 million doses will be sent to other countries in the coming months. The administration sent several million doses to Mexico and Canada last month, but has been holding onto the bulk of the stockpile as a reserve. AstraZeneca’s shot is authorized for use in a number of countries, even though dozens of people have died from post-vaccination blood clots in the UK and elsewhere. U.S. drug regulators are considering granting emergency authorization but have not yet done so. “Given the strong portfolio of vaccines that the United States has already authorized and that is available in large quantities, including two 2-dose vaccines and one one-dose vaccine, and given …