The Dallas Morning News

DALLAS – New research from Rice University could give the annual flu vaccine a shot in the arm.

Bioengineer Michael Deem has invented a method that could help the flu shot – which contains a mix of flu strains that changes each year – more closely match the strains that are making people sick. In theory, the research could help vaccine developers choose the most effective flu-fighting mix for that year.

“It seems we’ve developed a tool for vaccine design,” Deem said. He reported his findings this month in Los Angeles at a meeting of the American Physical Society, and has also passed them along to flu-control experts.

Doctors who specialize in the flu say Deem and his colleagues may be onto something.

“His technology offers a very accurate way of anticipating what virus strains we have to use for the vaccine,” said Mohammad Madjid of the University of Texas Health Science Center at Houston, who studies the link between the flu and heart attacks.

“More importantly,” he added, “is it a good match for this year or not? That’s a big problem right now.”

Early each year, the World Health Organization in Geneva recommends which three strains to include in the next winter’s flu vaccine for both hemispheres. Which strains get picked depends on which ones are most widespread and whether any new or particularly virulent strains have surfaced recently.

The three chosen strains, or versions of them, are then grown for months in chicken eggs before being tested for safety. By autumn, the flu vaccine is distributed to health providers nationwide.

The shot contains killed versions of the three strains, which means it has to closely match the strains that are circulating among people. Doctors currently test the closeness of the match through ferret tests.

But those tests aren’t always accurate, Deem said.

“As far as we know, we’re the first people to show this relative lack of correlation,” he said. “We find that a little surprising.”

Instead, his mathematical model compares genetic sequences for the part of the flu strain that triggers the biggest immune response. The method appears to predict a match much better than the ferret studies do, he said.

Looking back to 1971, he said, the research seems to explain why some annual vaccines performed well while others did not. It could also help doctors decide which strains to include in upcoming vaccines.

For instance, last year’s flu shot included a strain called Wyoming, but Deem’s model suggested that a related strain called Kumamoto might have been more effective. Next year’s shot will replace Wyoming with an emerging strain called California, a decision his research supports.

Klaus Stoehr, who runs the flu program for the WHO, has told Deem that he is interested in any way to improve the vaccine’s effectiveness.

Vaccines are expected to be in ample supply this year. Last winter, a vaccine shortage prompted more than 16 million people to give up their shot. Still, 4.5 million doses were left unsold, health officials announced last week.

Deem became interested in the flu vaccine when he got his 1998 shot at a Costco in Los Angeles. The nurse giving him the shot told him he might be more likely to get the flu if he skipped the next year’s dose.

That didn’t seem to make sense, so Deem began researching the flu. He read about the phenomenon known as “original antigenic sin,” in which a person’s immune system recognizes a flu strain but then tries to fight it the same way it fought the first flu strain it ever saw.

Thus, he said, skipping a flu shot can make a person more likely to get the flu than if he or she had never gotten a shot at all.