What is Hib? Doctors sound alarm on deadly bacterial disease

Doctors are raising concerns about the potential return of Hib, a bacterial disease that can cause serious illness and death in babies and young children, as vaccination rates fall across the U.S. 

Before a vaccine was available in 1987, about 20,000 children every year would suffer severe Hib infections, and 1,000 would die. More than half of the children who developed serious Hib disease were younger than 1 year old. 

Here’s what we know: 

What is Hib?

The backstory:

According to the U.S. Centers for Disease Control and Prevention, Hib is short for Haemophilus influenzae type b, not to be confused with the viruses that cause the flu. Hib can cause several different kinds of infections, mostly in children under 5, but sometimes in adults with certain medical conditions. The infections can range from mild, like ear infections or bronchitis, to severe, including sepsis, meningitis, pneumonia and airway obstruction. 

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"Infants with sepsis and meningitis caused by Hib can get sick very quickly and die before the illness is even diagnosed," said Dr. Kimberly Collins, associate professor of family medicine at the University of Washington’s Department of Family Medicine. 

Prior to the vaccine, Hib was the leading cause of bacterial meningitis among children under 5 in the U.S. Meningitis, an infection of the lining of the brain and spinal cord, can lead to brain damage and deafness.

The CDC estimates there are now fewer than 50 Hib cases a year in the U.S., about 5% of which are fatal. 

Is Hib making a comeback?  

Big picture view:

Doctors are pointing to two recent Florida Hib cases and an overall decline in childhood vaccinations as cause for concern. 

Dr. Paul Offit, director of the Vaccine Education Center at Philadelphia Children’s Hospital, said Panama City pediatricians treated two cases of Hib within a six-month period last year. A 4-month-old died and a 2-year-old was in a coma with brain abscesses and seizures. Neither child was vaccinated. 

Dr. Kathryn Edwards, a vaccine safety expert and professor of pediatrics at Vanderbilt University Medical Center in Tennessee, told NBC News that the hospital recently treated two cases of meningitis caused by Hib, the first cases in "a number of years," she said.

What they're saying:

"Fortunately, many doctors, like myself, that have trained in the past 20 years, have never seen a case of Hib meningitis or epiglottis thanks to the Hib vaccine," Collins said. "I worry that these cases that have been highlighted in Florida are just the tip of the iceberg."

Offit and Collins say more children will be at risk for Hib infections amid declining vaccination rates in the U.S. – fueled in part by Health Secretary Robert F. Kennedy’s vaccine skepticism and his efforts to overhaul the nation’s child vaccine schedule. 

A judge has temporarily blocked Kennedy’s childhood vaccine overhaul, but Hib was not one of the vaccines the Trump administration tried to remove from the list. 

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"This vaccine continues to be recommended by the American Academy of Pediatrics and the CDC," Collins said. 

Doctors fear under-reported Hib cases 

Dig deeper:

Offit and Collins also fear Hib cases could be under-reported because the CDC has scaled back programs that track diseases and deaths.

"Immunization rates among U.S. children are clearly declining," Offit wrote in his blog. "As a consequence, the U.S. is experiencing [a] greater number of cases and deaths from measles, influenza and whooping cough than has been seen in decades. Isn’t it possible that Hib infections and deaths are also increasing? We need to know exactly what’s going on. Otherwise, we can’t effectively counsel our patients and respond to outbreaks of preventable diseases."

The other side:

The CDC did not respond to requests for comment. 

Hib cases in the US

By the numbers:

As of March 21, the CDC reported eight Hib cases so far in 2026: two in Ohio, two in New York, one in Kansas, one in North Carolina and one in Tennessee, according to NBC News. 

CDC data on Hib is often lagging because states don’t report cases as quickly as they do other diseases. 

Protecting against Hib

What you can do:

CDC guidance calls for three to four Hib shots (depending on which brand) for all kids younger than 5. The CDC says the vaccines are safe and 93% effective in preventing bacterial disease. 

"It is important for parents who choose not to vaccinate to be aware that their child should be evaluated promptly if they do develop a febrile illness," Collins said. "They should advise doctors that their child is not vaccinated against Hib so that they can be evaluated promptly for possible Hib infection. This evaluation may require more invasive testing … but is important for early diagnosis and treatment."

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