Dry ice is poured into a box containing the Pfizer-BioNTech Covid-19 vaccine as it is prepared to be shipped at the Pfizer Global Supply Kalamazoo manufacturing plant in Portage, Mich., Sunday Dec. 13. (AP Photo/Morry Gash, Pool) WASHINGTON (CN) — Ramping up production, drugmakers Pfizer and BioNTech announced Wednesday that they will supply the United States with an additional 100 million doses of its vaccine for Covid-19 by July of next year. This announcement ups the total number of vaccines to be distributed to 200 million. Some 70 million of those doses would be delivered by June 30 with another 100 million delivered no later than July 31.