AAP E-Breaking News
Friday, January 23, 2009
The U.S. Centers for Disease Control and Prevention (CDC) today
announced that five cases of Haemophilus influenzae, type b (Hib),
invasive disease (meningitis, pneumonia and epiglottitis) were
confirmed in 2008 in Minnesota. This is the highest number of cases of
this vaccine-preventable disease in children under 5 years of age that
Minnesota has seen since 1991.
Three patients had received no vaccinations due to parent or guardian
deferral or refusal of vaccinations. One of the unimmunized patients, a
7-month-old infant, died of Hib disease. Two of the remaining children
received age-appropriate immunizations. One child, a 5-month-old, had
received two Hib immunizations. The other child was 15 months old and
was fully vaccinated for age but, subsequent to Hib infection, was
diagnosed with an immune deficiency (hypogammaglobulinemia).
Hib vaccine is recommended for all infants and is provided as a two- or
three-dose primary series (depending on product) in the first 6 months
of life, plus a booster dose after 12 months. Because of a Hib vaccine
shortage since November 2007, the Advisory Committee on Immunization
Practice (ACIP) has recommended that babies receive only the primary
series and not the booster dose, unless the child has a specific
chronic disease that places the child at greater risk for invasive
disease. The shortage is expected to last into mid-2009. It is
critically important that all children receive their primary series of
three doses of a Hib-containing vaccine on schedule during this
shortage. Currently available Hib formulations are ActHib (PRP-T) and
Pentacel (DTaP -IPV/Hib). Either formulation can be used to complete
the three-dose primary series. Pediatricians should use whichever
formulation is available locally to keep infants on schedule.
A Morbidity and Mortality Weekly Report (MMWR) dispatch will be available (
click here to view ). Information for parents and providers is also available (
click here to view ) . The MMWR dispatch covers recommendations for ensuring that all eligible patients receive all currently recommended doses of this important immunization as well as guidance for those infants who have chronic conditions that qualify them for the booster dose.
AAP News addressed the Hib vaccine shortage in its December 2008 issue ( click here to view ).
Given the vaccine shortage, prolonged booster deferral, and reduced
compliance with the primary series coverage, the increase in the number
of Hib cases in Minnesota likely reflects a weakening of herd immunity
-- that is, the percentage of immunized children in the population has
dropped below a certain critical level. The recent cases of Hib
invasive disease serve as a reminder that serious vaccine-preventable
diseases do occur if infants and children are not vaccinated.
Physicians also should remember to review immunization status when
evaluating a child with fever since evaluation of unimmunized children
with fever and/or lethargy may differ.
