The US Centers for Disease Control and Prevention on Thursday urged doctors and health agencies to be more vigilant for suspected cases of invasive Haemophilus influenzae type B in children under age 5, partly because of an existing shortage of childhood Hib vaccine which will continue at least until mid-2009.

Haemophilus influenzae type B is a bacterium that can on rare occasions be deadly, invading the lining of the brain, bloodstream or lungs. Infection can cause meningitis, sepsis or pneumonia, leading to brain damage or death, CDC epidemiologist Mike Jackson said. Before any Hib vaccine was available, some 20,000 US children would get serious and sometimes fatal Hib infections every year, the CDC noted.

The shortage is due to the fact that Merck & Co Inc last year recalled its Hib vaccines because production equipment may not have been properly sterilized. The company initially said its PedvaxHIB and COMVAX would return to the US market late this year. However, in October, it said they would not do so until mid-2009.

To deal properly with the current shortage, the CDC officials are recommending giving the Hib vaccine to infants, but holding off on a recommended booster shot for children age 12 to 15 months, except those at increased risk for Hib disease.

“Right now the recommendations are to make sure all children get the primary vaccine series, and providers should defer giving the booster dose until the vaccine supply increases. We are not worried about sudden increases in Hib disease, but we are worried over time that, not having the booster, we could start to see increases in Hib,” Jackson said.

Therefore, the CDC urges doctors, health officials and parents to be extra alert for Hib infections during the shortage.

The CDC warning was published in the Nov. 21 issue of its journal Morbidity and Mortality Weekly Report.