The first update in almost 20 years to the Centers for Disease Control and Prevention’s statement on Haemophilus influenzae type b will reflect changes in the epidemiology of the disease and the vaccines available to prevent it.
The CDC’s Advisory Committee on Immunization Practices unanimously approved a draft of the updated statement on Haemophilus influenzae type b (Hib) at the committee’s meeting Feb. 20.
Dr. Elizabeth C. Briere* summarized the draft statement, which lists the currently available and licensed vaccines, with no changes to previously published recommendations on routine use. But the statement includes guidance for special populations not included in the 1993 statement, consistent with the 2013 IDSA Clinical Practice Guideline for Vaccination of the Immunocompromised, which has not yet been published; as well as 2012 Red Book recommendations, 2011 ACIP General Recommendations on Immunizations, and 2009 ACIP Guidelines for the Prevention and Treatment of Opportunistic Infections for HIV-Infected Adults and Adolescents.In the years since the first Hib vaccine –a polysaccharide vaccine – was licensed in 1985, and the first conjugate Hib vaccine was licensed in 1989, the incidence of invasive Hib infection among children aged under 5 years has dropped dramatically, and has remained low through the 2000s, Dr. Briere of the CDC’s National Center for Immunization and Respiratory Diseases, pointed out at the meeting.
The special populations listed are Alaskan natives and American Indians, children aged under 24 months with invasive Hib, preterm infants, and high-risk groups (those with functional or anatomic asplenia, HIV, IgG deficiency, early component complement deficiency, and recipients of hematopoietic stem cell transplant and chemotherapy).
The guidance for high risk groups includes the recommendation to provide one dose of Hib vaccine to asplenic children aged 60 months and older and asplenic adults who are unimmunized**; and for HIV-infected children aged 60 months and older, who are unimmunized, she said. The Hib vaccination is not recommended for HIV-infected adults.
For patients undergoing an elective splenectomy, who are aged 15 months and older and are unimmunized, one dose of vaccine prior to the procedure is recommended. For children undergoing chemotherapy or radiation therapy who are aged younger than 59 months, revaccination is not required if routine Hib doses were administered 14 or more days before starting treatment. But if the dose is given within 14 days of starting treatment – or during therapy – the recommendation in the guidance is to repeat doses starting at least 3 months following the completion of treatment, Dr. Briere said.
In the updated statement, the guidance for chemoprophylaxis – which was limited in the old statement – is consistent with the guidance in the 2012 Red Book, and includes recommendations for the use of rifampin as chemoprophylaxis, she added.
The draft of the statement was updated after a review of Hib vaccine recommendations, including a draft of IDSA clinical practice guidelines for vaccination of the immunocompromised host, peer-reviewed literature, and surveillance data; and was reviewed by ACIP’s meningococcal and Haemophilus influenzae type b vaccine work group and ACIP voting members, providing comments, prior to the ACIP meeting.
There are 15 experts in immunization-related fields on the ACIP committee, which develops written recommendations for the routine administration of vaccines to children and adults in the civilian population.
*Updated: 2/26/13
**CORRECTION: A previous version of this story incorrectly described the asplenic patients who should receive the Hib vaccine.