Hib Vaccine Administration Guidelines for Children

Catch-up Vaccination Guidelines

For children aged 15 through 59 months who have not completed their primary Hib vaccination series, no further doses of any monovalent or combination Hib conjugate vaccine are indicated, as stated by the Advisory Committee on Immunization Practices (ACIP) 1, 2
The ACIP recommends that unvaccinated children receiving the first dose at age 15 through 59 months need only a single dose of Hib vaccine 3
By age 3 years (36 months), children have developed natural immunity to Hib, making additional catch-up doses unnecessary after 15 months of age unless the child has specific high-risk conditions, according to the ACIP 1

For children aged 12-59 months with high-risk conditions, such as asplenia, HIV infection, immunoglobulin deficiency, or those undergoing chemotherapy, the ACIP recommends the following:
- If they received 0 or 1 dose before age 12 months: 2 doses should be given, 8 weeks apart 2
- If they received ≥2 doses before age 12 months: 1 dose should be given 8 weeks after the last dose 2
- If they completed a primary series and received a booster dose at age ≥12 months: no additional doses are needed, as per the ACIP guidelines 2

For infants beginning vaccination at 2-6 months of age, the ACIP recommends two schedule options:
- 3-dose primary series if using PRP-T vaccines (ActHib, Pentacel, or MenHibRix) 1
- 2-dose primary series if using PRP-OMP vaccines (PedvaxHIB or Comvax) 1
A booster dose is recommended at age 12-15 months regardless of which primary series was used, according to the ACIP 1

The ACIP states that for healthy 3-year-old children without high-risk conditions, no further Hib doses are needed 1
For 3-year-olds with high-risk conditions, the ACIP recommends following the specific recommendations for high-risk groups 2

The Advisory Committee on Immunization Practices (ACIP) recommends that previously unvaccinated children aged ≥60 months (5 years and older) who are not considered high-risk generally are immune to Hib disease and do not require catch-up vaccination 4, 5
The peak risk for invasive Hib disease occurs in infants and young children, with approximately two-thirds of cases affecting children less than 15 months of age 6
The risk of invasive Hib disease decreases dramatically after age 5 years in immunocompetent children 4

Children with functional or anatomic asplenia (including sickle cell disease or scheduled splenectomy) should receive a single dose of any licensed Hib conjugate vaccine 4, 5
Children with HIV infection should receive a single dose of any licensed Hib conjugate vaccine 4, 5
Children with immunoglobulin deficiency (including IgG2 subclass deficiency) should receive a single dose of any licensed Hib conjugate vaccine 4, 5
Children with early component complement deficiency should receive a single dose of any licensed Hib conjugate vaccine 4, 5
Recipients of hematopoietic stem cell transplant should receive 3 doses of Hib conjugate vaccine regardless of prior vaccination history 5
Children receiving chemotherapy or radiation therapy for malignant neoplasms should receive a single dose of any licensed Hib conjugate vaccine 4, 5

The ACIP provides clear age-based guidance: children aged ≥60 months (5 years and older) do not need Hib vaccination unless they have a high-risk condition 4, 5
A single dose of any licensed Hib conjugate vaccine should be administered to unimmunized children aged ≥60 months who have a high-risk condition 4, 5