What will this flu season be like?

Experts say different strain of flu could dominate

ANN ARBOR, Mich. – Influenza is notoriously unpredictable. That's what makes preventing it so challenging.

Inside the "Flu Lab" at the University of Michigan's School of Public Health, there is a team dedicated to monitoring both the spread of flu and the effectiveness of the vaccine. It's critical information that helps guide decisions that can save lives.

But as Americans roll up their sleeves to get this year's flu shot, the severity of last year's season cast a big shadow.

"The U.S., almost alone in the Northern Hemisphere, had a very bad flu season related to the H3N2," said Dr. Arnold Monto, a world-renown flu expert at the University of Michigan.

Monto said the predominance of the H3N2 virus last year was bad because H3N2 tends to cause more severe complications and the vaccine often doesn't work as well against it.

It's still very early in this year's flu season, but there are hints that a different flu virus called H1N1 could be the dominant flu this year. The H1N1 strain used to make this year's vaccine is actually from Michigan. It's called A/Michigan.

"It was specimens from our lab that helped pull this together to identify what is needed," said Monto. "We showed that there was a difference between the A/California, which is the previous one, and the A/Michigan. And this related to the history of people's exposure to flu. Flu occurs many times in your life and you are imprinted, is what we call it, by whatever occurred first. And in people who had exposure with this other virus, the A/California didn't work as well as the A/Michigan, and that's why we now have a Michigan virus in the vaccine."

This "Flu Lab" is one of five centers across the country that collect data for the Centers for Disease Control and Prevention.

"Those estimates that come out in the news to say 'The vaccine is X percent effective,' those come directly from the University of Michigan and four other places," said assistant professor Emily Martin.

In addition to samples collected from hospitals and clinics, researchers also monitor local families.

"They visit us every time they're sick, and we get samples, and we find out when they're vaccinated. For some families, we take blood a few times a year to see immunologically how the vaccine is working," said Martin.

Martin and Monto are frustrated that the vaccine is sometimes not as effective as everyone would like, but wish more people understood the benefits even a "poor match" can offer.

"With many other diseases, if we could tell you that you could take one shot that would reduce your risk of dying or going to the doctor, or even getting infected with this disease by 30 percent, that's as good as many other interventions that we have on the market. Many things that are more expensive, a lot more side effects than flu vaccine," said Martin.

"Even some protection is better than no protection," said Monto. "The flu vaccine is one of our safest vaccines." 

Monto also urges more people to take advantage of antiviral drugs, which work best in the first two days of the illness.

"People tend to go to the doctor five days, six days, two weeks out, 'I'm still coughing.' Well there isn't a whole lot you can do at that point. It's only early that you can do something about flu," said Monto. 

While many people have heard of the antiviral drug Tamiflu, the Food and Drug Administration recently approved a new single-dose antiviral drug called Xofluza. In addition to shortening symptoms, Monto said, it appears it may reduce your ability to transmit the flu to others. 

His best advice heading into flu season?

"Be aware. Be ready. Get vaccinated. Because even though it isn't an ideal vaccine, it does protect us. And be sure that if you are getting sick in the flu season, think about getting treated," said Monto.