Senior Editor The Food and Drug Administration on Sunday granted emergency use authorization to Johnson & Johnson's Janssen single dose COVID-19 vaccine for use in individuals 18 years of age and older, making it the third vaccine to prevent COVID-19 that has been cleared for use in the United States. The shipment of 3.9 million doses of Janssen's COVID-19 vaccine began today. Some 800,000 of those doses are expected to go directly to pharmacies, according to an ABC News report. J&J said it expects to deliver enough single-shot vaccines by the end of March to enable the full vaccination of more than 20 million people in the United States. The company plans to deliver 100 million single-shot vaccines to the U.S. during the first half of 2021.