By John Enger, Minnesota Public Radio News

It has been a rough six weeks at the Johnson household in Bemidji. Early last month, 2-year-old Walter — the youngest child — brought home the flu. He gave it to his big brother, Henry. Not long after, Rachel said she and her husband, Jason, got sick, too.

“It just totally wiped us out,” she said. “There’s fever, runny nose, cold sweats, hot sweats. It feels like you got a crazy amazing workout the day before, because every single muscle is sore and aching.

They never got flu shots — a decision Rachel said she regrets. The family has been in and out of the clinic since January. Walter developed pneumonia, thanks to his flu-compromised immune system, and spent weeks coughing like a chainsmoker.

“You could sleep all day,” Johnson said, “but you can’t sleep when you have little kids.”

The Johnsons are far from alone. This flu season has been breaking records. The federal Centers for Disease Control and Prevention reports that nearly 8 percent of all hospital visits nationwide are from the flu — rivaling the swine flu pandemic of 2009.

The Minnesota Department of Health reports flu-related hospital stays are on track to surpass records from three years ago, when the H3N2 influenza virus put more than 4,000 Minnesotans in the hospital.

Some hospitals were barely prepared for the influx of patients. Heading into the season, Sanford Medical Center in Bemidji was short on IV bags, thanks to the hurricanes in Puerto Rico. IVs are vital for keeping flu patients hydrated.

“Typically we keep two to three weeks of IV fluids on hand,” said Sanford chief medical officer Dr. David Wilcox. “There were points where we got down to two or three days. So coming into this season we were very frightened about that.”

New weekly statewide flu estimates was expected to be released Thursday. According to Minnesota Department of Health infectious disease specialist Karen Martin, flu outbreaks and hospital stays seem to have peaked a few weeks ago. Since then, numbers of H3N2 cases appeared to have dropped off slightly.

“We’re certainly hoping so,” she said. “Sometimes it’s hard to know whether it’s a blip, but it does look like it’s starting to go down.”

That’s good, since 63 children in the U.S. have already died from the flu this season. At least one of those was in Minnesota. Flu-related deaths among the elderly are certainly much higher. The CDC only has rough estimates, however, its data suggest this season may surpass the 2014-15 death toll of 56,000.

The severity of this year’s flu season once again highlights problems with the effectiveness of the flu vaccine. Most vaccines made in the U.S. are still grown in chicken eggs, like they were during WWII.

According to Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, H3N2 flu vaccines have a habit of mutating slightly in the chicken eggs. By the time the vaccine is injected into people, he said it’s not all that effective.

Last year, during Australia’s earlier flu season, it was only about 10 percent effective.

Earlier this week U.S. Sen. Amy Klobuchar called for more funding and research on better flu vaccines. That’s something Osterholm has urged for years.

“What’s desperately needed right now is not just increased funding,” he said. “We also need global coordination in doing the research. We can’t just put money out there and hope that we’ll do something better.”

Public health officials said the current flu vaccine is still a vital tool in combating flu. Even if it is less effective against the H3N2 virus this year, they argue it may offer better protection against other strains of flu that are also circulating.