The manufacturing process takes just a few weeks -- but the vaccine can't be sent out just yet. Now begins the testing -- samples from each batch undergo 50 tests -- examining everything from purity to strength to sterility. That testing takes up 85 percent of the three to four months it takes to release a batch of vaccine. The U.S. Food and Drug Administration signs off on each batch before its shipped out.
Producing the vaccine was slow going at first because the H1N1 virus didn't grow quickly. "We knew that new viruses are slow growers," Sanofi Pasteur CEO Wayne Pisano told me, "and so we had anticipated a low yield. But it was even lower than we had expected."
Pisano says Sanofi has now figured out how to work with the virus to speed up the growth. The company is producing 5 million doses a week, and hopes to double that in the weeks ahead. It has already shipped 20 million doses, half the nation's supply so far.
That the company was even able to ramp up production was partly due to luck, partly to hard work. Sanofi was busy making the seasonal flu vaccine in its old manufacturing plant when H1N1 appeared last April. Its new manufacturing had not yet been licensed by the FDA. FDA approval came through in May -- just in time. It was 21 days later that the CDC shipped Sanofi a "seed" strain of the H1N1 virus to see if the company could turn it into a vaccine.
One month later, the company was able to begin manufacturing the new vaccine in its new plant. Without the capability, Sanofi would have been forced to decide whether to stop production of the seasonal flu vaccine in its old plant to make way for H1N1. Instead, the company says it will turn out 50 million doses of seasonal flu this year, and 75 million of H1N1.
It has turned into a lucrative business for the company. Sanofi expects to make $500 million dollars from sales of the H1N1 vaccine in the fourth quarter, according to Associated Press reports.
Company officials say they've had to run operations 7-days a week, 24 hours a day in order to produce the millions of doses of H1N1 vaccine. Pisano said employees have postponed honeymoons, and that one worker attended the birth of his son in the morning and was back on the job by afternoon. During a normal flu season, employees and the equipment get a breather from August until October, when seasonal flu production is on hiatus. Not this year.
Sanofi is also testing the vaccine samples as soon as they ready. Susan Powers, Vice President of Quality Operations for Sanofi Pasteur U.S., says usually they would wait until they have 10 or so samples to run tests. Now she says "we don't wait. We test all (H1N1) samples within a day of receipt."
Vaccine production has not come soon enough for those eager to get protection from the H1N1 virus, but Sanofi insists it cannot move any faster.
"We are where we are,' said Chris Viehbacher, CEO of parent company Sanofi-Aventis, "We are working as hard as we can."