Hib vaccine
The Hib vaccine, or Haemophilus influenzae type B vaccine, provides critical protection against serious infections caused by the Hib bacterium, including meningitis, epiglottitis, and sepsis. These infections can have severe consequences, including fatality, and are particularly dangerous in children. The vaccine works by introducing a harmless component of the Hib bacterium, stimulating the immune system to recognize and combat the actual bacterium without causing disease. The Hib vaccine was first released in 1985 and became part of the recommended pediatric immunization schedule in 1989. It has since been incorporated into combination vaccines, such as Pentacel, which also protect against other diseases like diphtheria and polio.
The implementation of the Hib vaccine has led to a significant decline in Hib-related diseases, particularly meningitis and epiglottitis, which were once common in children. The mortality rate for those infected with Hib was previously around 5%, with many survivors facing permanent complications. Thanks to widespread vaccination efforts, Hib-related illnesses have become rare, illustrating the vaccine's successful impact on public health. However, awareness of the symptoms and seriousness of other bacterial meningitis causes remains essential.
Hib vaccine
- ALSO KNOWN AS: Haemophilus influenzae type B vaccine
Definition
The Hib vaccine protects against disease caused by the bacterium Haemophilus influenzae type B. This bacterium (also called Hib) can lead to infection of the coverings of the spinal cord and brain (meningitis) and infections of the epiglottis (epiglottitis) and blood (sepsis), among other areas of the body. These infections are dangerous and can be fatal, even with adequate treatment.
Other strains of H. influenzae exist and are commonly referred to as nontypeable H. influenzae. These strains can cause infection, though these diseases are much less virulent than those caused by H. influenzae. These infections, which are common in the ear, sinuses, and lower respiratory tract, rarely spread to the bloodstream and rarely cause meningitis.
Mechanism
The Hib vaccine is made by taking the shell (the polysaccharide coating) of the Hib bacterium and linking it to another protein. Injection of this safe combination incites the body to produce an immune response against this Hib bacteria coating without actually causing the disease, thus protecting against future infection.
History
The first version of the Hib vaccine was released in 1985 and was placed on the recommended pediatric immunization schedule starting in 1989. The vaccine eventually was combined with the DTaP (diphtheria, tetanus, and pertussis) vaccine in 1996 as TriHIBit (diphtheria, tetanus, pertussis, and Haemophilus influenzae type B) and later with the DTaP and inactivated poliovirus vaccines as Pentacel.
Administration
The administration of the Hib vaccine varies depending on the brand of vaccine used. Those receiving the ActHIB, Hiberix, Pentacel, Vaxelis vaccines are recommended to receive the vaccine at two, four, and six months, with a booster between twelve and fifteen months. The Pentacel vaccine also protects against diphtheria, tetanus, pertussis (whooping cough), and polio. The PedvaxHIB vaccine is administered at two and four months, with a booster between twelve and fifteen months.
Impact
The Hib vaccine is highly effective at preventing the diseases commonly caused by the bacterium H. influenzae. Before the development of this vaccine, Hib was the leading cause of meningitis in children. It is estimated that the mortality rate among infants and children who contracted this illness was 5 percent, with an even greater incidence of permanent brain damage or hearing loss, or both, among survivors. It is important to note that other bacterial causes of meningitis still exist. Still, the incidence of meningitis has dramatically declined since the Hib vaccine was added to the immunization schedule.
Epiglottitis, a serious disease most commonly caused by Hib, was widespread before Hib vaccination became standard. However, it has virtually disappeared as a disease, and many pediatricians have learned of this illness only by anecdote.
Bibliography
"About Hib Vaccine (Haemophilus Influenzae Type B Vaccine)." CDC, www.cdc.gov/vaccines/vpd/hib/hcp/about-vaccine.html. Accessed 3 Oct. 2024.
Behrman, Richard E., Robert M. Kliegman, and Hal B. Jenson, editors. Nelson Textbook of Pediatrics. 18th ed., Philadelphia: Saunders/Elsevier, 2007.
Harvey, Richard A., Pamela C. Champe, and Bruce D. Fisher. Lippincott’s Illustrated Reviews: Microbiology. 2d ed., Philadelphia: Lippincott Williams & Wilkins, 2006.
Loehr, Jamie. The Vaccine Answer Book: Two Hundred Essential Answers to Help You Make the Right Decisions for Your Child. Naperville, Ill.: Sourcebooks, 2010.
Plotkin, Stanley A., Walter A. Orenstein, and Paul A. Offit. Vaccines. 5th ed., Philadelphia: Saunders/Elsevier, 2008.
"Vaccine Information Statement - Hib - Haemophilus Influenzae Type B." CDC, www.cdc.gov/vaccines/hcp/vis/vis-statements/hib.html. Accessed 3 Oct. 2024.