Chiron had its manufacturing licence suspended last October by the UK Medicines and Healthcare products Regulatory Agency after contamination problems were uncovered at its Liverpool plant, leading to shortages. But it was given the go-ahead to resume production last week.
The US company's chief executive, Howard Pien, told journalists and analysts in a conference call that problems at the plant had been due to human error, now resolved, and the company was pulling out the stops to get production back into full swing. But he would not commit to meeting the full quota for the next flu season.
He said that the complexity of the vaccine manufacturing process, it was too early to forecast either the number of doses the company hopes to produce, or indeed give any financial guidance for the coming year. Fluvirin achieved sales of $100 million for Chiron in the third quarter of 2003, but the company had to write off its entire 2004 inventory as a result of the plant shutdown. That resulted in a $91 million charge to earnings in the third quarter last year.
Meanwhile, Chiron still has to provide weekly updates to the MHRA on the plant's progress, and will have to wait for a full US Food and Drug Administration inspection - when all stages of manufacturing are operational - before it can resume US sales of the vaccine.
Mr Pein said the firm was aiming to provide financial guidance when it unveils its first quarter earnings in April.