Haemophilus influenzae type b (Hib)

What is Hib?
Hib Symptoms
Conventional Treatment for Hib
When is the Hib Vaccine Given
Duration of Protection
Ingredients in the Hib Vaccine
FDA Hib Vaccine Package Inserts
Hib Vaccine Reactions
The Bottom Line and the Hib Vaccine
Who Should Not Get the Hib Vaccine
References
Resources

What is Hib?

Hib disease is a contagious condition caused by the bacteria Haemophilus influenzae type B. It is spread through contact with mucus or droplets from the nose or throat, as when people cough, kiss, sneeze, or share personal items like drinking cups and toothbrushes. The infection is carried by nose and throat excretions into the bloodstream and then settles into various parts of the body, often the spinal fluid and the brain.

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Hib Symptoms

Hib is transmitted like the common cold and starts with similar symptoms.

Mild Symptoms

fever can develop
doctor will likely treat this with antibiotics: ear or sinus infection, bronchitis, or suspected pneumonia
child will recover without parents or doctor knowing that the cause of illness was Hib.

Moderate Symptoms

all of the above mild symptoms
lethargy
an ill appearance
possibly labored breathing that should prompt chest X-ray and blood testing for infection
oral antibiotics (or perhaps an intramuscular injection) to treat suspected internal bacterial infection
if blood result reveals Hib bacteria, the child will be admitted to the hospital for several days of IV antibiotics
child will be ill but probably recover completely

Severe Symptoms (invasive Hib disease)

symptoms of meningitis, pneumonia, arthritis, cellulitis, or epiglottitis
hospitalization with aggressive antibiotic treatment and possible respiratory support
most respond gradually and recover fully (may spend days to weeks in the hospital)
complications of Hib meningitis, such as hearing loss , learning problems, or nerve injury, occur in about 25 percent of children with invasive Hib
The case-fatality rate of invasive Hib disease is 2%–5%, despite appropriate antimicrobial therapy.

A graph of the declining Hib incidence rate per 100k children less than five years old in the United States from 1987-1999.

http://www.cdc.gov/vaccines/pubs/pinkbook/hib.html

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Conventional Treatment for Hib

Antibiotics (third-generation cephalosporin (cefotaxime or ceftriaxone), or chloramphenicol in combination with ampicillin)
Ampicillin resistant strains of Hib are becoming more common in the United States [1]

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When is the Hib Vaccine Given?

The Hib vaccine is given at two months, four months, six months, and fifteen months of age.

The longer you wait to vaccinate your child from Hib, the less number of doses are needed.
If breastfeeding your infant, chances are very likely that your child has maternal antibody immunity until 6 months of age (see CDC note below the chart).
If you choose to vaccinate, you may skip the first few doses of Hib vaccine.

An information table containing a detailed schedule for Hib vaccines.

http://www.cdc.gov/vaccines/pubs/pinkbook/hib.html

Important to Note From the CDC [1]:

The most striking feature of Hib disease is age-dependent susceptibility. Hib disease is not common beyond 5 years of age. Passive protection of some infants is provided by transplacentally acquired maternal IgG antibodies and breastfeeding during the first 6 months of life. In the prevaccine era peak attack rates occurred at 6–7 months of age, declining thereafter. The presumed reason for this age distribution is the acquisition of immunity to Hib with increasing age.

Translation: If breastfeeding your infant, she has maternal IgG antibodies against Hib for the first 6 months of life. Hib is not common beyond 5 years of age, the reason is this: most children came into contact with Hib by this age, giving them lifetime natural immunity (pre-vaccine era).

For more information: CDC/Alternative Vaccine Schedules

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How Long Does Hib Vaccine Protection Last?

The majority of older children are immune to Hib, probably from asymptomatic infection as infants. [1]
Nascimento-Carvalho CM, de Andrade AL. Haemophilus influenzae type b vaccination: long-term protection. J Pediatr (Rio J). 2006 Jul;82(3 Suppl):S109-14:

Introduction of the Hib conjugate vaccine produced great decline in the incidence of invasive Hib disease in childhood in countries where this vaccine was introduced into the routine immunization schedule. Nevertheless, the resurgence of invasive Hib disease in some regions has challenged several researchers to identify the reasons for this epidemiological pattern, as well as the measures to be implemented in order to avoid such a phenomenon.

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Ingredients in the Hib Vaccine

The ActHIB brand

Hib sugar/ tetanus toxoid complex
Sucrose sugar
Saline solution (salt water)
Formaldehyde— > 0.5 micrograms

The PedVaxHIB brand

Hib sugar/ Neisseria protein complex
Saline solution
Aluminum —225 micrograms

The Hiberix brand

Hib sugar/ tetanus toxoid complex
Lactose sugar
Saline solution
Formaldehyde— > 0.5 micrograms

If you would like specific information regarding each ingredient, including studies:

Vaccine Ingredients

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FDA Hib Vaccine Package Inserts

Pentacel FDA Package Insert (Sanofi Pasteur)- Hib, DTaP, and polio combo
Hiberix FDA Package Insert (GlaxoSmithKline)- Hib and tetanus combo
ActHIB FDA Package Insert (Sanofi Pasteur, SA)- Hib and tetanus combo
PedvaxHIB FDA Package Insert (Merck)- Hib and meningococcal combo
MENHIBRIX FDA Package Insert (GlaxoSmithKline)- Hib, meningococcal, and tetanus combo

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Hib Vaccine Reactions

According to the CDC, moderate or severe reactions to Hib vaccine should be reported to and checked by a doctor immediately. If any of these reactions were to occur they would happen within a few minutes to a few hours after receiving the shot. All adverse reactions should also be reported to the Vaccine Adverse Events Reporting System (VAERS).

Signs to look for include:

High fever
Behavior changes
Difficulty breathing
Hoarseness or wheezing
Weakness
Fast heartbeat
Dizziness
Hives
Paleness

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The Bottom Line and the Hib Vaccine

According to Ronald Kennedy, Ph.D., professor of microbiology and immunology at the University of Oklahoma Health Sciences Center, the combination vaccine of Hib, hepatitis B, and DTP may render the hepatitis B vaccine INACTIVE.
If you plan to vaccinate, separate out the vaccines and give on different days.
If you are nursing your infant, chances are good that she has antibodies against Hib infection until at least 6 months of age. If you are concerned, you may test antibody titres to Hib or give dose of Hib at 7 and/or 15 months of age (if you’d like to reduce number of doses).
There is an association between the Hib vaccine and insulin-dependent diabetes. [12]

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