Vaccine makers Pfizer, Moderna pledge boost to U.S. supply after sluggish rollout Isaac Stanley-Becker and Christopher Rowland, The Washington Post Feb. 23, 2021 FacebookTwitterEmail Three vials of the 'Moderna COVID-19 Vaccine' are pictured in a new coronavirus, COVID-19, vaccination center at the 'Velodrom' (velodrome-stadium) in Berlin, Germany, Wednesday, Feb. 17, 2021.Michael Sohn/AP WASHINGTON - Drug companies told lawmakers Tuesday that they project a major increase in vaccine deliveries that will result in 140 million more doses over the next five weeks, saying they have solved manufacturing challenges and are in a position to overcome scarcity that has hampered the nation's fight against the coronavirus.