For much of 2009, the swine flu was the biotech industry’s cash cow.

The virus’s sudden contagion last spring spread rapidly and lucratively to the life-sciences community, where a handful of companies scrambled to assemble enough money and staffers to launch studies, conduct research, and shape products to respond to the first documented flu pandemic in 40 years.

Their battle against the H1N1 virus generated millions of dollars in revenue and lifted some stock prices to new yearly highs, with some leaping as much as 700 percent over the course of last year.

But the pandemic’s relatively light impact—only 16,455 people died worldwide, compared with 1 million to 50 million deaths in past flu pandemics—and a shorter-than-expected flu season has brought some of those biotechs, not to mention their stock prices, back to earth. The companies are now evaluating their performance and lessons learned last year to push for improving flu vaccine technology in time for the next outbreak.

“The opportunity for a specific product for the swine flu has essentially passed,” said Frank Malinoski, a former MedImmune executive who spent most of last year consulting for the Centers for Disease Control and Prevention and small companies preparing for pandemic diseases. “The companies in the area now are either concentrating on how they can be part of the seasonal flu market or how they can prepare for the next pandemic.”

The swine flu frenzy touched several local biotechs in different ways.

One behemoth, MedImmune, won a contract for up to $453 million to manufacture and deliver its FluMist vaccine to the federal government, boosting its parent company’s revenue and stock price. At least two other companies, Novavax Inc. and Cel-Sci Corp., sped up flu-related vaccine research. While they did not recognize any sales revenue from the pandemic, both companies watched their stock prices soar.

Though MedImmune and its parent, London pharmaceutical giant AstraZeneca, are now unlikely to see another federal dollar from contracts for their widely used FluMist vaccine tailored to guard against H1N1.

Last year, the government paid $389 million for FluMist, the first vaccine to reach the clinic shelves. The unanticipated income helped convert a potential 5 percent slide in AstraZeneca’s U.S. revenue into a 4 percent bump in the fourth quarter and turn what would have been a roughly 2 percent revenue increase into a 9 percent jump for of 2009.

But now the Department of Health and Human Services will likely leave $64 million of that original $453 million contract with MedImmune on the table. With 74 million unused H1N1 vaccine doses of its own, the department plans to redirect those toward the next seasonal flu vaccine, which will include the H1N1 strain. Overall, the feds spent $1.6 billion on flu vaccines last year.

Although MedImmune spokeswoman Karen Lancaster said the H1N1 revenue injection was always understood to be a “onetime event,” the loss of that money this year is already having an impact on the parent company. AstraZeneca said it expects a mid-single-digit decline in this year’s revenue compared with last year.

Cel-Sci, another company that positioned itself at the center of the swine flu stage last year, watched its stock price swell from an 18-cent low to a $2.10 high in seven months.