What to expect from flu season this year

Expert says seniors could face extra risk

ANN ARBOR, Mich. – Flu cases have started popping up here and there around southeast Michigan. Does that mean we're in for an early flu season? Not necessarily.

"I would say by the end of October, beginning of November, we'll know if it's going to be an early season," said Dr. Arnold Monto, from the University of Michigan School of Public Health.

Monto is a world-renowned flu expert who helped write the textbook "Influenza." But even he can't predict the flu with any certainty.

"The problem is that we can really only go on what we already know," Monto said.

One thing experts do know is that children won't have the option of getting FluMist this year.

The "Flu Lab" at the University of Michigan was one of five centers working with the Centers for Disease Control and Prevention that found the nasal spray vaccine was not offering good protection for children last year.

"The company is going back to the drawing board trying to figure out exactly what the problem is," Monto said.

With an injection the only option, there is concern that fewer kids will be vaccinated this year, increasing the risk of child hospitalizations and deaths.

Monto is also concerned about what strain could dominate.

"Last year we had an A strain, the AH1N1 which is the one that caused the pandemic in 2009," Monto said. "We think it's unlikely that it's going to come back again. We think it's probably going to be the AH3N2."

It's a concern because the H3N2 strain typically hits hard in older people.

"That's where we see more hospitalizations," Monto said. "That's what we had two years ago."

It was also when the vaccine was a poor match. Monto is hopeful this year's vaccine will do better.

"We hope that this will match what's circulating," Monto said. "It generally is pretty close."

Adding to the confusion for consumers is that some of this year's vaccine is quadrivalent, protecting against four strains, while other shots are trivalent, protecting against just three.

"The difference between the four and the three is based on having two type B's in the vaccine compared to one type B in the vaccine," Monto said.

So why don't all of the shots include the fourth strain?

"There is a somewhat higher cost to the four in the vaccine than the three, which is why there still continues to be availability of what we call the trivalent," Monto said.

Monto said that while the quadrivalent vaccine probably does offer some extra protection, it really matters most for children who haven't been exposed to as many viruses as adults.

"With adults with all our experience with past viruses, we probably get more protection against the one that is not in the vaccine if you're getting three, than in children where you really need all four to be in the vaccine," Monto said.

It's too soon to know if this year's vaccine will be a good match for the flu that's circulating, but even if it's not, Monto said it's still worth getting a flu shot.

"If you don't get perfect protection, you can get protection against more severe disease," Monto said.

That means even if you do get sick, you're less likely to end up in the hospital, which is exactly what the "Flu Lab" found two years ago.

"We had close to 40 percent protection in preventing hospitalized cases," Monto said.