Decline in Disease Mortality

Decline of Childhood Hib Disease in the Hib Vaccine Era

Captured 2023-03-21

Document Highlights

Haemophilus influenzae type b (Hib) conjugate vaccines were first licensed for use in US children at least 18 months old in December 1987 and for infants at least 2 months old in October 1990. We evaluated trends in Hib disease…

Haemophilus influenzae meningitis incidence decreased by 82% between 1985 and 1991.

Both surveillance systems showed decreased rates of Hib disease in infants less than 1 year old before vaccine was licensed for use in this age group.

The decline of disease in infants less than 1 year old before licensure for this age group warrants further investigation.

Comments

While the Hib conjugate vaccines were first licensed for use in 18 month olds in 1987, they were not licensed for use in 2 month olds until late 1990 (October and December), and not recommended by ACIP (the CDC's Advisory Committee on Immunization Practices) for children 2 months of age and older until January 1991.

Sources: Haemophilus b Conjugate Vaccines for Prevention of Haemophilus influenzae Type b Disease Among Infants and Children Two Months of Age and Older Recommendations of the ACIP

The current Hib vaccines are generally considered responsible for the decline in the incidence of Hib meningitis.

However only 28% of 2 year olds in the US were fully vaccinated for Hib in 1992.

HIB Vaccination Coverage of 2 Year Old Children in the US – 1992

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Decline of Childhood Hib Disease in the Hib Vaccine Era