Good Question: Why Isn't The Flu Shot More Effective?

MINNEAPOLIS (WCCO) – Many of the Minnesotans ending up in the hospital because of influenza are those who have had the flu vaccine.

That got us wondering: Why isn't the flu shot more effective?

"We think we can do much better with flu vaccine," said Dr. Mike Osterholm, the director of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota. Osterholm has studied influenza for years.

In a research report published in October of 2012, his team found that children under the age of 7 who get the live flu mist have great success -- on average 83 percent don't get sick.

But among healthy adults getting a traditional flu shot, the average success rate is just 59 percent. Better than zero, but still…

"We can't be using a vaccine that was around in the '40s and '50s, and call that modern," Osterholm said.

The flu isn't like mumps or measles; it constantly changes. Vaccine makers try to account for that by predicting which strains will be out there, and matching the vaccine.

"Just today I heard a very prominent medical doctor in the media say, 'We nailed the match this year.' Well, it doesn't really mean much," Osterholm said.

He added: "We've seen years when the match was supposedly very good, and vaccine protection was really bad. We've seen years where the match wasn't very good, and yet vaccine protection was above average."

Osterholm advocates the development of what's called a novel-antigen game–changing vaccine, one that would cover many different strains of flu over a longer period of time. But developing a new kind of vaccine isn't cheap.

"We believe to bring one new flu vaccine to market will take over $1 billion. You gotta believe you need a new flu vaccine before you commit a billion dollars," he said, arguing that the U.S. government's policy towards approving vaccines makes it challenging for private companies to spend the money to get a new vaccine approved.

Another financial obstacle toward developing a new vaccine is that success could be a money-loser.

"What if we could do it so you needed to get vaccinated once every 10 years? Now you wouldn't get vaccinated every year...so in a sense, it's a disincentive. You've just cut your market by tenfold," Osterholm said.

But he said there's hope for success. In 2009, there was a flu pandemic around the world. Researchers looked at people who were infected by the last pandemic in the 1930s and '40s, and they still had immunity. If a vaccine could mimic that, it would be truly a game-changer.