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Haemophilus influenzae type b (Hib)

Each year, Haemophilus influenzae type b (Hib) kills more than 200,000 children worldwide and causes an estimated two to three million cases of Hib disease, mostly in developing countries. Hib mainly affects children under five years of age and is a significant cause of meningitis (inflammation of the covering of the brain) and bacterial pneumonia in children. Hib can be treated with antibiotics, and conjugate Hib vaccines, mainly in the form of pentavalent (diphtheria-tetanus-pertussis-hepatitis B-Hib) vaccines, provide more than 95 percent protection in infants receiving the complete series of pediatric vaccination.

Hib resources on the Vaccine Resource Library were mainly gathered during PATH’s Hib project, which conducted activities in Senegal from 2005 to 2009. For additional resources, visit the Hib page on the World Health Organization website.

View resources on Haemophilus influenzae type b (Hib)

Hib disease

  • Each year an estimated two to three million cases of Hib disease and more than 200,000 Hib deaths occur worldwide. The majority of Hib disease is in developing countries, and Hib’s victims are primarily children less than five years old.
  • Hib bacteria are a significant cause of childhood meningitis (inflammation of the covering of the brain) and bacterial pneumonia in children. Even though “influenza” is part of its name, Hib does not cause the “flu.” Hib can leave children with permanent neurological disabilities, including brain damage, hearing loss, and mental retardation. Most serious Hib disease occurs in children between 6 and 12 months old. Children who have not been breastfed and those with underlying medical conditions, such as immune system deficiencies, are at greater risk for Hib disease.
  • Hib normally establishes itself in the nose or upper throat and is spread through sneezing, coughing, or speaking closely with an infected person. Children often carry Hib bacteria without showing any signs or symptoms (asymptomatic carriers), but they can still infect others.
  • Hib can be treated with the use of antibiotics; however, antibiotic resistance is a growing concern in the treatment of Hib in the developing world. Furthermore, if children are not treated early enough, antibiotics may not be sufficient.

Hib vaccines

  • Several Hib conjugate vaccines have been licensed and are prequalified for use by the World Health Organization (WHO). They are manufactured by both multinational and developing-country manufacturers. All have shown protective efficacy in early infancy. The Hib component has shown a very low level of side effects (temporary redness or swelling at the injection site).
  • Conjugate Hib vaccines are highly immunogenic, conferring more than 95 percent protection in infants receiving the complete series of pediatric vaccination (two to three doses starting after six weeks old). A booster shot is usually required at 12 to 18 months. To reduce the number of injections, Hib vaccine is often given in combination with diphtheria-tetanus-pertussis and hepatitis B vaccine. In the developing world, this is referred to as a pentavalent vaccine. In high-income countries, the antigen can be combined with acellular pertussis vaccine, with or without hepatitis B and injectable polio vaccines.
  • Hib vaccines are routinely used in the childhood immunization programs of nearly all countries and territories, and since vaccine introduction, Hib disease has declined drastically, reaching very low levels in countries where vaccine has been used. Not only does Hib vaccine provide protection to vaccinated individuals, it also protects unvaccinated people through herd immunity. Studies in the Gambia, Indonesia, Chile, and Uruguay have all demonstrated significant declines in disease following vaccine use.
  • The WHO's Global Programme for Vaccines and Immunization recommends that the Hib vaccine be included in routine infant immunization programs in all countries.

Related diseases

There are several key causes of childhood pneumonia and meningitis (inflammation of the covering of the brain), including pneumococcus, Hib, and meningococcus bacteria. Learn more about pneumococcus. Learn more about meningococcus.

In addition, there are a number of repiratory diseases, all of which affect the lungs and airways, including pneumococcus, respiratory syncytial virus (RSV), Hib, and influenza. Learn more about pneumococcus. Learn more about RSV. Learn more about influenza.

For more information

Hib resources on the Vaccine Resource Library were mainly gathered during PATH’s Hib project, which conducted activities in Senegal from 2005 to 2009. For additional resources, visit the Hib page on the World Health Organization website.

References

Page last updated: June 2013.

Photo: PATH/Evelyn Hockstein.