Swiss drug giant Novartis says it has redeployed 300 workers from other divisions into its vaccines unit to meet what Chairman and CEO Dr. Daniel Vasella calls the "huge demand" for H1N1 shots.
"You can be assured we have put in everything we can to accelerate and maximize the output," Vasella told CNBC.
But he also acknowledged the company is hamstrung to a certain extent by "physical constraints of production capacity" and low H1N1 vaccine manufacturing yields that are as little as one-fifth the normal yield.
As a result, Vasella said that the company will not be able to ship "large quantities" of the vaccine until around the end of December and that some of the approximately 100 million doses Novartis plans to make may not arrive until the first quarter of next year. Many states, municipalities, clinics and physicians are reporting H1N1 vaccine shortages.
Dr. Vasella also stood by the vaccine's safety, claiming that it has been studied more extensively than any seasonal flu vaccine. More than 8,000 people have been enrolled in Novartis' H1N1 vaccine clinical trials.
In its earnings press release today, Novartis said it expects to book $400 million to $700 million in flu vaccine sales in the fourth quarter.
The FDA has approved H1N1 vaccines from Novartis, Sanofi-Aventis and AstraZeneca .