From Jon Cohen and Martin Enserink, excerpts:
For proprietary reasons, Lurie would not name the delay issues at each manufacturer, but said “one company was just really overoptimistic” in its delivery predictions to HHS. Initially, all of the makers of inactivated vaccine had trouble with the “potency assay” used to ensure that 15 micrograms of influenza antigens are present in each dose. Once that was corrected, said Lurie, this company lost 20% to 35% of its antigen during the “recalibration.”
One [company] had a new production line to fill doses of vaccine into individual syringes. “Getting up the new production lines with prefilled syringes was really slow,” Lurie said. The third company had “major production problems” that Lurie said she could not describe in detail for proprietary reasons. Basically they had difficulty making “acceptable” vaccine that did not contain an immune booster called an adjuvant, which is used in several countries but not the United States.
In response to questions about safety, Frieden stressed at the press conference that these companies are using the same processes to make the novel H1N1 vaccine that they use each year to make 100 million or so doses of seasonal product. But if they have so much experience making the product, why so many snafus with the pandemic vaccine? “Almost every flu season, something goes wrong,” said Lurie, emphasizing that she was referring to manufacturing, not safety.