It has been nearly a year since an outbreak of H1N1 flu sent a group of 4H kids home early from the Minnesota State Fair.
That marked the beginning of a major influenza outbreak that sickened thousands of Minnesotans throughout the fall and winter. Eight children, and dozens of young and middle-age adults died from the flu in the state.
The pandemic strain of flu is not expected to cause disruptions this year at the State Fair, which opens Thursday. But there are signs that the flu season could be off to an early, and somewhat unusual, start.
The World Health Organization declared an end to the H1N1 pandemic just a few weeks ago. The virus is still circulating here and there around the globe. But overall, far fewer people are becoming ill from it.
It's still possible that H1N1 cases will surge again in the United States this fall. But at the moment, flu viruses aren't following the classic, post-pandemic pattern, said Dr. Greg Poland, an infectious disease expert at the Mayo Clinic.
"Something unusual has happened. Typically, what we would see would be a third wave of H1N1," he said. "We haven't seen that. Doesn't mean it couldn't happen. But we haven't seen it thus far."
Poland said what doctors have seen early in the season are outbreaks of H3N2, a seasonal variety of flu that was virtually squeezed out during the pandemic.
In the past few weeks, Iowa has reported several outbreaks of the strain. No one knows why H3N2 is resurfacing now. But some public health officials think of it as a generally good development.
"It's not like good news, like you won the lottery. But on the other hand, it does sort of signal a return to a more normal presentation for influenza," said Kris Ehresmann, director of an infectious disease epidemiology and vaccination unit at the Minnesota Department of Health.
Ehresmann said H1N1 is a scary flu because it is so hard on children and young adults. They made up the bulk of the nation's estimated 15,000 flu deaths last season.
In contrast, H3N2 flu causes most of its deaths in the elderly. While the early occurrence of the seasonal strain is not ideal news for them, Ehresmann said seniors will have a new weapon this year that may help them fight it more effectively -- a high-potency vaccine, just for people over age 65.
"We have known for quite awhile that as people age, their immune response to vaccines isn't as robust or strong," Ehresmann said. "The hope is that by giving them this higher dose, that they will have a better immune response than they would have with a regular flu vaccine."
“Typically, what we would see would be a third wave of H1N1. We haven't seen that.”Dr. Greg Poland, Mayo Clinic
But early hints about the upcoming flu season are just that -- hints. Public health officials really don't know what to expect. For that reason, they say no one should assume they're safe from flu this year.
Just in the past week, emergency departments in some New Zealand hospitals were suddenly overwhelmed by a surge in H1N1 cases, during what should be the end of their flu season.
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said that same scenario could easily happen in Minnesota again.
He thinks more than one-third of the state's population will be vulnerable to H1N1 flu this season because they didn't get vaccinated last year -- and he doesn't think they will this year either.
"I think that we may be in for quite a ride yet, as we look at this new flu season about to hit us," Osterholm said. "It again really calls out for why we want the younger population, which is the one most likely to be impacted by this, to get vaccinated."
For the first time ever, public health officials are urging everyone age six months and older to get a flu vaccine, which is given in both shot form and nasal mist.
Previously, health agencies had recommended flu vaccinations for specific groups, including children, caregivers, people with high-risk conditions and healthcare workers. But they changed their advice this year because they say the recommendations were just too complicated for most people to understand.
The flu vaccine this season protects against three strains of flu, including H1N1 and H3N2. Some large retail pharmacies have already received vaccine.
The Minnesota Visiting Nurse Agency will offer flu vaccinations during all 12 days of the Minnesota State Fair. Many schools are planning to set up flu clinics for students and other members of the community this fall, the Health Department said.