Changing vaccine systems no easy shot

Cell-culture technology Bush advocates would require major investment by manufacturers


The threat of a pandemic may persuade the makers of flu vaccine to give up the chicken eggs they've used for decades and begin moving to a newer, faster production system.

The question is whether they're willing to abandon the tried-and-true - or do it soon enough to head off the next potential public health disaster.

Last week, President Bush branded current vaccine production methods "antiquated" and asked Congress for a $2.8 billion "crash program" to help the industry develop simpler and more flexible "cell-culture" technologies that can better keep up with new flu strains.

For decades, drug companies have made flu vaccines by growing viruses in millions of live, fertilized eggs. The system works well, but all agree that it's cumbersome, time consuming and hard to ramp up quickly in a public health emergency.

Cell-based production methods grow the flu virus in steel vats filled with living cells derived from monkeys, dogs, humans or even insects. Some vaccines produced this way have won limited approval in Europe, but none has been cleared for use here.

"By bringing cell-culture technology from the research laboratory into the production line, we should be able to produce enough vaccine for every American within six months of the start of a pandemic," Bush said.

Cell-culture technology is hardly new. The industry has used it successfully since the 1950s to produce vaccines for such viral ailments as polio, measles, mumps and tetanus.

But vaccine experts and drug makers say the industry has stuck with eggs for flu vaccine production because they work pretty well. And change would cost billions.

"We've got the plants set up. We've got the whole system worked out, and we're not going to rock the boat unless we have to," said Dr. Samuel L. Katz, a professor of pediatrics at Duke University and co-developer of the measles vaccine.

"Now, maybe we have to," he said.

Moving the industry to cell-based technologies will require billions - money for continued research and development, money to win federal approval for new cell lines in human products, money for human clinical trials.

When all that's done, drug makers will need millions more to build the factories to produce hundreds of millions of doses of the new vaccines every year.

That's why the president is asking Congress to help.

Proven technique

Len Lavenda was understandably miffed by Bush's use of the word "antiquated." He's a spokesman for Sanofi Pasteur of Swiftwater, Pa. The company, based in France, is one of the world's largest flu vaccine makers, and the last one with production in this country.

Sanofi Pasteur uses eggs.

"The fact is, it's a tried and proven technology that has worked well for us," Lavenda said. Other drug makers have abandoned the flu market in recent years because of low and inconsistent demand for flu vaccine and correspondingly slim profits - not problems with the egg-based vaccine technology.

"We believe our nation will remain dependent on egg-based technology for at least the short to medium term," Lavenda said. "We're looking at quite a few years before we can obtain licensure for commercial-scale, cell-culture flu vaccine."

Meanwhile, Sanofi is using an infusion of $41 million in federal tax dollars to expand and maintain its chicken flocks and enable year-round egg production.

Flu vaccine makers got into the egg business to start with, Katz said, because the first flu vaccines were developed before World War II - before the first cell-culture techniques were invented.

At that time, eggs were already being used to make yellow fever vaccines, and the technology proved to work well for flu vaccines, too. Drug makers who later adopted cell-culture technologies for other vaccines saw no reason to tackle the established technology for flu vaccines, Katz said,

Besides, he said, flu is a real headache because the viruses change so quickly.

"It's something you have to fiddle with every year," he said. By contrast, "we're making the same measles vaccine in 2005 that we made in 1963, when we developed the vaccine."

That might be changing. Several big drug companies, from Sanofi Pasteur to GlaxoSmithKline and Chiron, are developing cell-based flu vaccines.

No Maryland companies are known to be working on cell-based flu vaccine at the moment. But government and business leaders see it as an opportunity.

Baltimore Mayor Martin O'Malley, with backing from state officials and the Economic Alliance of Greater Baltimore, is pushing for a new cell culture vaccine production center in the city or elsewhere in Maryland.

"I think we've got a great shot at it," said Nipon Das, executive vice president of the Alliance, a nonprofit group dedicated to furthering the region's business interests.

Das said the group hopes to complete a feasibility study by the end of January.

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