Eight-year-old Liam Dahlberg stepped off the school bus with a headache one Thursday afternoon last spring.
The following Saturday morning, he was in a coma with no brain activity.
He was dead by Monday.
His doctors said the northwest Indiana boy contracted an aggressive form of H flu, a rare bacterial infection. He died in a Chicago hospital despite being a healthy kid and vaccinated against the disease, his mom, Ashlee Dahlberg, told the Sun-Times.
While doctors can’t say for sure how he got sick, one way that the disease can spread is through the unvaccinated, who are more likely to be infected and spread the disease. Unlike Illinois, Indiana does not require the vaccine as a part of a student’s immunizations.
The boy’s mom worries her son’s tragic case could become more common as vaccine skepticism rises and vaccination rates fall.
“His doctors told us that he was handed his death card the second he contracted it,” Dahlberg said.
H flu, also called haemophilus influenzae, is uncommon — each year about 200 cases are recorded in Illinois and roughly 150 are documented in Indiana, according to data from the Centers for Disease Control and Prevention. Despite the name, H flu is a bacteria, not a virus like the flu. It can lead to pneumonia and meningitis.
But it isn’t always fatal or life-threatening. Cases can be mild, usually presenting as an ear infection in kids or as a chest cold in adults, the CDC says.
Just like all communicable diseases, H flu cases dropped off during the COVID-19 pandemic and have steadily risen in the years since. Indiana saw more cases in 2022, the most recent year data is available, than before the pandemic.
Before a vaccine was developed and made widely available in the late 1980s and early 1990s, haemophilus influenzae type b was the most common form of H flu. Roughly 20,000 kids, mostly ages 5 and younger, contracted H flu each year in the early 1980s, and about 1,000 died, according to the CDC. Those rates dropped dramatically after the vaccine was widespread.
Type b is the only type of H flu with a vaccine. Other versions are rare but can also cause serious infections like meningitis.
In 2024, the vaccination rate for kids in Lake County, Indiana, where Liam was from, was 80%, according to data from the Indiana Department of Public Health.
The vaccination rate for H flu at Chicago Public Schools slightly dropped during and after the pandemic — which disrupted vaccinations for several diseases — but remains high for the current school year at 93%. Herd immunity for H flu is reached at a 90% vaccination rate.
Herd immunity helps protect children who can’t get vaccines for medical reasons or don’t make as many anti-bodies to fight an illness despite having the vaccine, public health experts say.
‘A devastating case’
Liam was a healthy boy who loved to play outside, ride his dirt bike and work with his hands, his mom said. He was a fierce protector of his baby sister, and he dreamed of one day owning his own landscaping company. He lived in Lowell, Indiana — a small town about 60 miles south of the Loop — with his parents and his two sisters.
Liam had seasonal allergies, and was recently diagnosed with asthma and used an inhaler.
Headaches weren’t unusual for him, especially given his allergies. When he came home with the headache on April 24, Ashlee Dahlberg gave him ibuprofen, and he felt well enough to play outside.
But a couple hours later, he came home screaming in pain, telling his mom his head “hurt real bad,” she said. He spiked a fever overnight and woke up early the next morning delirious and unable to keep his balance.
They took him straight to the emergency room. Within two hours, his doctors in Lowell transferred him to University of Chicago Comer Children’s Hospital, fearing he had a severe brain infection.
At Comer, he was put on more antibiotics and a lumbar puncture confirmed he had fulminant haemophilus influenzae. His doctors suspected he had type b. But a culture test of his spinal fluid could not officially determine the correct type, according to his medical records.
Liam has “a devastating case of H flu meningitis,” a doctor wrote in one report. “We do not yet know the type of H flu William acquired. … We are suspicious for Haemophilus influenza type b (Hib) … and will do everything we can to get these answers for family.”
Two days later, his brain swelled, then shrunk, putting major pressure on his brain stem. His brain showed no activity, and he went into a coma. Liam never woke up.
Dahlberg wasn’t familiar with H flu, aside from remembering it as one of the many vaccines her kids received as babies. It was also the first time some of Liam’s doctors had seen it.
“It’s a little mind-blowing,” Dahlberg said. “Some of the doctors working on his team, who had been there for 25 years, had never seen this before.”
Liam’s doctors explained to his parents that vaccines both limit the chance of someone contracting the disease and limit how much of the virus or bacteria they carry if they do get infected.
His doctors suspect if he had type b, he would have come in contact with a person who was unvaccinated and a carrier of H flu. Liam was also likely exposed the same week he contracted it, given how severely and quickly the infection progressed, his doctors told his parents.
She pleaded with other parents to make sure their children are vaccinated — not only to protect their own child but other kids like Liam.
“This just shows how important vaccinations are,” she said. “What may be a slight cold for one is a hospital visit for another.”
‘A tidal wave of misinformation for all vaccines’
As anti-vaccine sentiment continues to grow, vaccines that never faced controversy are getting lumped in with the “myth and lore” that’s plagued other better-known effective and safe vaccines, said Dr. Ravi Jhaveri, the division head of pediatric infectious diseases at Lurie Children’s Hospital.
“H flu has never been a controversial vaccine, the myth and lore has never been there,” Jhaveri said. “But this particularly highly effective vaccine gets caught up in the tidal wave of misinformation for all vaccines.”
When anti-vaccine disinformation was more fringe, Jhaveri said, vaccination levels were higher, and there were fewer cases of vaccine preventable illnesses.
“That was because people believed in the information they were getting from trusted experts,” he said. “But since experts have become undermined and these voices that have no expertise at all are more prevalent and have a platform, we’re seeing an increase in these illnesses that can be prevented with a vaccine.”