On this edition of Africa 54: U.S. President Joe Biden has formally announced that his administration is donating 500 million doses of the Pfizer COVID-19 vaccine to 92 low- and middle-income countries; French President Emmanuel Macron has declared an end to the Barkhane counter-terrorism operation in West Africa's Sahel; & In a recent interview with VOA's Medina Dauda, the U.S. Ambassador to Nigeria, Mary Beth Leonard, spoke about the role of development initiatives in sustaining a solid security partnership between Nigeria and the United States.