From the Guidelines
The HIB vaccine is crucial in protecting against Haemophilus influenzae type b (Hib), a bacteria that can cause severe infections, particularly in young children, and its function is to prevent serious illnesses such as meningitis, pneumonia, epiglottitis, and bacteremia by stimulating the immune system to produce antibodies against the bacteria's protective capsule. The standard HIB vaccination schedule for children includes doses at 2 months, 4 months, 6 months (depending on the brand), and a booster at 12-15 months of age, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1. This vaccine has been highly effective in reducing the incidence of invasive Hib disease in children under 5 years, with a 99% decrease in annual incidence between 1989 and 2000 1. The vaccine works by creating immunity before natural exposure occurs, which is particularly important because HIB infections can progress rapidly and were once a leading cause of bacterial meningitis in children under 5 years before widespread vaccination.
Key Points
- The HIB vaccine prevents severe illnesses including meningitis, pneumonia, epiglottitis, and bacteremia.
- The standard HIB vaccination schedule for children includes doses at 2 months, 4 months, 6 months, and a booster at 12-15 months of age.
- The vaccine has an excellent safety profile with only mild side effects like redness at the injection site or low-grade fever, which typically resolve quickly.
- Vaccination with Hib conjugate vaccine leads to decreases in oropharyngeal colonization among both vaccinated and unvaccinated children 1.
Recommendations
- All children should receive the HIB vaccine as part of their routine vaccination schedule.
- Children who missed their primary series should receive catch-up vaccination up to age 5.
- Certain persons at increased risk for Hib disease, such as those with early component complement deficiencies, immunoglobulin deficiency, anatomic or functional asplenia, or HIV infection, should also receive the vaccine 1.
From the Research
Function of the Haemophilus influenzae type b (HIB) Vaccine
The Haemophilus influenzae type b (HIB) vaccine is designed to protect against severe pneumonia, meningitis, and other life-threatening illnesses caused by the Haemophilus influenzae type b bacterium [ 2 ]. The vaccine is particularly important for children under the age of 5, as they are most susceptible to Hib disease [ 2 ].
Efficacy of the HIB Vaccine
Studies have shown that the HIB vaccine is highly effective in preventing invasive Hib disease, with an efficacy rate of:
- 84% against invasive Hib disease [ 3 ]
- 75% against meningitis [ 3 ]
- 69% against pneumonia [ 3 ] The vaccine has also been shown to be safe and well-tolerated, with rare serious adverse events [ 3 ].
Mechanism of Action
The HIB vaccine works by inducing antibody production against the polysaccharide capsule of the Haemophilus influenzae type b bacterium [ 4 ]. The vaccine is designed to be administered in infancy, and it has been shown to be effective in reducing the risk of invasive Hib disease in young children [ 4 ].
Impact of the HIB Vaccine
The widespread use of the HIB vaccine has led to a significant reduction in the incidence of Hib infections and associated morbidity and mortality worldwide [ 5 ]. However, many children remain unimmunized or underimmunized against Hib, particularly in limited-resource countries, and future efforts to further reduce the disease burden of Hib infections remain a high priority [ 5 ].
Key Points
- The HIB vaccine is highly effective in preventing invasive Hib disease [ 2,3 ]
- The vaccine is safe and well-tolerated [ 3 ]
- The vaccine works by inducing antibody production against the polysaccharide capsule of the Haemophilus influenzae type b bacterium [ 4 ]
- The widespread use of the HIB vaccine has led to a significant reduction in the incidence of Hib infections and associated morbidity and mortality worldwide [ 5 ]