Is This Deadly Childhood Illness Making a Comeback?

Some physicians are increasingly worried that Haemophilus influenza type b (Hib), a potentially disabling and sometimes lethal bacterial infection in children, is making a comeback as vaccine hesitancy rises.

Serious cases are being reported in California, New York, Florida, and many other states, MedPage Today has learned.

The fact that there were two severe cases in Panama City, Florida, alone in the past 6 months is “frightening, because that’s what you would expect across the entire country in a year,” Paul Offit, MD, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told MedPage Today.

One child died and the other is “pretty much brain dead,” Offit said. He learned of the new cases coincidentally, as he was giving a talk to about 30 Florida physicians during a meeting on a proposed state law that would relax childhood immunization requirements.

One of the physicians in attendance, Eehab Kenawy, MD, mentioned the two cases at the hospital where he practices — and he suspects there are many more.

“Now I have to worry about Hib, treating patients from out of town who aren’t vaccinated … and worrying about all sorts of things you don’t know until the blood culture or spinal tap results come back or God forbid, the child dies,” he told MedPage Today.

Before the Hib vaccine became available in 1987, some 20,000 U.S. children developed severe Hib disease each year — many of whom were under 18 months of age — and about 1,000 died. But that all stopped with the vaccine, when cases dropped to about 50 a year, with about a 5% mortality rate, Offit said.

Offit believes the CDC isn’t paying attention to case counts of many diseases as it has cut back on personnel and funding for surveillance. That comes as “immunization rates among U.S. children are clearly declining” as seen in the uptick in measles, influenza and whooping cough, Offit noted in his Substack.

A January report in the Annals of Internal Medicine showed that among 82 CDC disease databases, 34 had gaps or pauses lasting more than 6 months. “The CDC isn’t the CDC anymore,” Offit said.

“We need to know exactly what’s going on,” he wrote. “Otherwise, we can’t effectively counsel our patients and respond to outbreaks of preventable diseases.”

HHS spokesperson Andrew Nixon said the CDC is not seeing an increase in Hib infections among children. He provided a link to 2026 data showing a total of 4 cases among kids under age 5, with 21 cases in 2025 and 27 in 2024. The data come from the CDC’s National Notifiable Diseases Surveillance System.

Kathryn Edwards, MD, a vaccine safety expert and professor emeritus at Vanderbilt University Medical Center in Nashville, Tenn., told MedPage Today about a newer case in the last month in an unvaccinated child. And then, a few days later, she heard about yet another case. She declined to give details on the cases, referencing health record privacy laws.

“And it’s just not clear whether this is something that the current CDC is looking into, or what the status is in terms of the numbers of cases,” she said. “This is a very severe illness that often would lead to brain swelling.”

The California Department of Public Health reported that from 2018, when there were no cases, to 2024, healthcare professionals reported 11 cases of Hib illness in children under 5, the age below which Hib vaccination has been strongly recommended. Three were in 2022, 2 in 2023, and 1 in 2024. One of those children died, state officials said.

Of those 11, 7 children did not have any Hib vaccinations and 3 had not completed the full 3- or 4-dose series (depending on the brand).

Last week, ProPublica reported how HHS Secretary Robert F. Kennedy Jr.’s vaccine skepticism may be at the root of lower pediatric vaccination rates and more serious, preventable childhood illnesses and used Hib as its lead example. Adam Ratner, MD, a pediatric infectious diseases physician at NYU Langone Health in New York, described treating a child with Hib meningitis in 2022, and two more in 2023, all unvaccinated.

For Kenawy, the two cases have put him and his fellow clinicians in a very difficult position, and “the only good that may come out of this is that [parents who reject vaccines] may realize how serious some of these diseases are, and it may make them change their mind.”

Part of the problem in getting a handle on actual case counts is that many states report all types of Haemophilus influenza in the same bucket, including far less serious non-type cases. For example, Texas data show an increase of Haemophilus influenzae, invasive cases from 11 in 2015 to 538 in 2024. Not all of those are Hib.

Offit also is worried that physicians today — most of whom have never seen a case – won’t recognize the disease until it is too late. For starters, because Hib is spread through small droplets from the mouth or nose, family members potentially exposed should receive antibiotic prophylaxis, Offit said. He noted, however, that the disease is usually much less severe in adults.

The bacteria can cause a variety of illnesses that physicians not used to seeing it may not associate with Hib, he said.

“It is primarily a disease in children less than 5 years old, but can cause sepsis, septic arthritis, pneumonia, and meningitis. But the thing that scares us the most is a swollen epiglottis,” Offit said, which can cause the child to suffocate.

There are emergency protocols to calm the child with Hib and a swollen epiglottis — transport to surgery and intubate so if the epiglottis flopped on top of the trachea and occluded it, a tracheostomy could be rapidly performed, he said. One would never transport a child like that in an ambulance.

“Sadly, younger physicians are about to be re-educated about what these diseases look like,” he said. “Physicians just have to let parents know that these viruses and bacteria are still out there. And a choice not to give their child a vaccine is not a risk-free choice. It’s a choice to take a greater risk.”