Biden says US is securing 600 million vaccine doses by July

President Joe Biden speaks during a visit to the Viral Pathogenesis Laboratory at the National Institutes of Health Thursday in Bethesda, Md. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, listens at right. (AP Photo/Evan Vucci)

BETHESDA, Md. — President Joe Biden said Thursday that the U.S. will have enough supply of the COVID-19 vaccine by the end of the summer to inoculate 300 million Americans.