At a mostly virtual global COVID-19 summit today on the sidelines of the UN General Assembly meeting, President Joe Biden pledged another 500 million doses of Pfizer-BioNTech vaccine for lower- and middle-income countries and rallied support for other measures to end the pandemic, including improving the supply of medical equipment and aligning around common goals.In other developments, the World Health Organization (WHO) said yesterday that global cases continue to decline, with deaths also falling in most regions.US announces 500 million more dosesBiden said the vaccine doses pledged today will begin shipping in January.