The increased speed and capacity is not unexpected, said Robert Van Exan, president of Immunization Policy and Knowledge Translation, a vaccine production consulting firm. “Nobody’s ever produced mRNA vaccines at this scale, so you can bet your bottom dollar the manufacturers are learning as they go. Pfizer’s COVID-19 vaccine is made at threePfizer plants: starting in Chesterfield, Missouri, moving to Andover, Massachusetts, and finishing in Kalamazoo, Michigan. As of Saturday, about 20.6 million doses of the Pfizer vaccine had been administered nationwide.
