HHS funds development of cell-based flu vaccines

Apr 4, 2005 (CIDRAP News) – Sanofi Pasteur has won a $97 million federal contract to develop cell-culture technology for making influenza vaccines and to design a facility to use this technology to make a pandemic flu vaccine, federal officials have announced.

Flu vaccines are currently grown in chicken eggs, a process that takes at least 6 months. Several companies have been experimenting with ways to grow vaccines in mammalian or other cells, in the hope of speeding up the process. The chance that H5N1 avian flu could lead to a human flu pandemic has stimulated these efforts.

In the Apr 1 contract announcement by the Department of Health and Human Services (HHS), HHS Secretary Mike Leavitt said, "This action begins the process of speeding up influenza vaccine production, improving surge capacity and scaling up U.S. manufacturing capability."

Under the 5-year contract, Sanofi Pasteur (formerly Aventis Pasteur) will develop inactivated flu vaccines using human cells and manufacture enough doses for clinical trials, the HHS statement said. Sanofi was the main supplier of inactivated flu vaccine for the US market in the 2004-05 flu season.

"In addition, Sanofi Pasteur will develop plans for a U.S. manufacturing facility capable of producing at least 300 million doses of a pandemic influenza vaccine using this technology," HHS said.

The statement said it takes nearly 9 months to make currently licensed flu vaccines. After health agencies select the three viral strains they think will be most common in the coming flu season, the strains must be adapted to grow in eggs. The adapted virus strains are injected separately into millions of fertilized eggs, which are then incubated. Finally the viruses are harvested from the eggs, killed, and blended into a vaccine that includes all three strains.

HHS cited several advantages of using cell-culture technology to make flu vaccines. Viruses don't need to be adapted to grow in eggs, and manufacturers can freeze cells in advance and then thaw and grow them in large volumes in the event of a shortage or pandemic. Also, the method is safe from certain risks associated with egg-based production, such as the chance of eggs being contaminated by various poultry diseases. Finally, cell-based vaccines could be used by people who can't receive the currently licensed vaccines because they are allergic to eggs.

The HHS announcement didn't suggest how fast it would be possible to produce vaccines with cell-culture technology or how soon Sanofi might have a vaccine ready for clinical trials. HHS officials could not be reached in time to provide more information for this report.

According to a Washington Post report published last November, officials at several companies that are developing cell-based flu vaccine technology said the production process would take about 5 months, shortening the conventional process by about a month.

In November 2004 HHS awarded a contract to Sanofi Pasteur to ensure a year-round supply of eggs for flu vaccine production. The government also has awarded contracts in the past year to develop and test a human flu vaccine based on the H5N1 avian flu virus.

See also:

Apr 1 HHS announcement

Nov 9, 2004, HHS announcement of contract to provide egg supplies for flu vaccine production

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