A conjugate vaccine (made from a tiny fragment of the bacteria's sugar-coat attached to a protein) against Hib was introduced in the UK and Ireland in 1992, and provides long-lasting immunity. Since the introduction of the Hib vaccine, the incidence of meningitis cause by Haemophilus influenzae has been reduced by over 90%, across the UK and Ireland1,2 .
Introduction of the conjugate Hib vaccine has also reduced carriage rates of the bacteria3 . Before the vaccine was introduced, a large proportion of children under age 5 carried the bacteria. Now that vaccination is routine, carriage of the bacteria is much less common, and as a result protection is extended to the rest of the population, even those not immunised. This is called 'herd immunity'.
Is the vaccine safe?
Millions of doses given to children worldwide over more than a decade have established an excellent safety record. Adverse reactions are no more common than for other vaccines routinely given to babies and children. The Hib vaccine is not a live vaccine and cannot cause even a very mild form of the disease.
Who gets the vaccine?
Currently in the UK, the vaccine is offered to babies at 2, 3, and 4 months of age in the routine immunisation programme, with a Hib booster (given as combined Hib/MenC) offered at 12 months of age. From 10 September 2007 children will be given a Hib-containing vaccine when they have their pre-school booster vaccines at 3-4 years of age. Children born between 13 March 2003 and 3 September 2005 who have already had their pre-school booster injections will be invited for an extra Hib booster (given as combined Hib/MenC) 4, 6 .
In addition, in the UK, Hib vaccine is recommended for older children and adults with certain immune deficiencies such as people with HIV or those without a functioning spleen (asplenics and hyposplenics), including people who have sickle cell disorder4 .
Currently in the Republic of Ireland, the vaccine is offered to babies at 2, 4 and 6 months of age in the routine immunisation programme, with a Hib booster dose offered at 12 months of age.
In addition to babies, in the Republic of Ireland, Hib vaccine is recommended for all children under four years of age who have not previously had the vaccine and for anyone with malfunctioning or lack of spleen, sickle cell disease, HIV or other immunodeficiency, irrespective of how old they are5 .
Is Hib still an important cause of meningitis?
The Hib vaccine is very effective, but no vaccine is 100% effective. It does not work as well in children with certain immune problems. In addition, a very small proportion of perfectly healthy children do not respond to the vaccine well enough to be protected against Hib meningitis. It is unusual for adults and older children to be susceptible to Hib infection, but cases are known to occur, particularly in hospitalised, sick and elderly patients. Illness caused by non-b types of Haemophilus influenzae is also being monitored.
Immunisation has dramatically reduced cases of Hib meningitis, but in countries which have not introduced the vaccine, Hib is still a major cause of serious disease in children.
UK Hib vaccine catch-up campaign: 10 September 2007 to 3 March 2009
After the small resurgence in Hib disease, apparent from the end of the 1990's, studies showed that protection from the 3-dose primary schedule wanes during infancy. This was addressed by the 2003 Hib catch-up campaign, and the 2006 introduction of a routine booster dose for all children at 12 months (as the combined Hib/Men C vaccine). However, there is a cohort of children born between March 2003 and September 2005 who were too young to have had a booster during the 2003 Hib catch-up campaign, and too old to have received the new Hib/MenC booster after it was introduced in 2006.
Following advice from the Joint Committee on Vaccination and Immunisation, a Hib booster is currently offered to children in this cohort, so that they are as well protected as older and younger children. Children in the target group are those born between 13 March 2003 and 3 September 2005.
For most of these children, the Hib booster is given as part of their pre-school immunisation, at approximately 3 years and 4 months of age. Until March 2009, the pre-school booster will be DTaP/IPV/Hib (rather than DTaP/IPV or dTaP/IPV). This will cover the majority of children in this cohort, as they have not yet received their pre-school immunisations.
Older children in this cohort who had already received their pre-school immunisation when the catch-up campaign began are being offered an additional appointment to receive the Hib/MenC vaccine.
Further information resources about the UK Hib vaccine catch-up
Immunisation Against Infectious Diseases: http://snipurl.com/c6v0
Letter from the Chief Medical Officer:
http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Professionalletters/Chiefnursingofficerletters/DH_076965
National Immunisation website:
http://www.immunisation.nhs.uk/publications/VaccineUpdate_143Jan08.pdf
Q&A for Hib booster campaign 2007 to 2009: http://www.healthpromotionagency.org.uk/Resources/children/pdfs/Hib%20QA.pdf
General References
1. JCVI Statement: Haemophilus influenzae type b (Hib) Disease and Hib Vaccine. Executive Summary. http://www.advisorybodies.doh.gov.uk/jcvi/hib.pdf (accessed 17 May 2007).
2. Health Protection Surveillance Centre. Hib FAQs, How safe and effective is the Hib vaccine? http://www.immunisation.ie/en/HealthcareProfessionals/Hib/#howsafe (accessed May 2007).
3. Frasch CE, Haemophilus influenzae Type b Conjugate and Combination Vaccines. 1995. Clin.Immunother. 4 (5):376-386
4. Department of Health. Immunisation against infectious diseases. Chapter 16: Haemophilus influenzae type B (Hib) pages 127-135. Ed Salisbury D, Ramsay M and Noakes K. 2006. Third edition. TSO. http://www.dh.gov.uk/en/Policyandguidance/Healthandsocialcaretopics/Greenbook/DH_4097254 (accessed 17 May 2007).
5. Immunisation Guidelines 2002.
http://www.ndsc.ie/hpsc/A-Z/VaccinePreventable/Vaccination/Guidance/ (accessed May 2007)
6. Professional Letter- Chief Medical Officer (2003)2: Planned HIB vaccination catch-up campaign: further information Department of Health. http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Professionalletters/Chiefmedicalofficerletters/DH_4004833 (accessed 17 May 2007)
Page last updated 17.07.08