Biden convenes global COVID-19 summit, U.S. pledges to share more vaccines President Joe Biden announced Wednesday that the United States is doubling its purchase of Pfizer’s COVID-19 shots to share with the world to one billion doses as he embraces the goal of vaccinating 70 per cent of the global population within the next year. President Joe Biden made the pledge at a virtual Covid-19 summit on the sidelines of the UN General Assembly, promising an “arsenal of vaccines”. While many high-income countries have now given at least one shot to…