Five children were infected in Minnesota with a bacterial infection known as Hib: Haemophilus influenzae type b last year. Three of them had not received any vaccinations, including a 7-month-old who died, according to the Centers for Disease Control and Prevention. One child had been partially vaccinated while the other got all the vaccination doses but was affected due to immunodeficiency.

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.  The infection affects infants and children under 5 years of age. According to CDC statistics, one in 20 children infected with Hib dies; survivors of the disease can become deaf and 10 to 30 percent have permanent brain damage.

Following the Minnesota cases, the CDC is urging all parents to ensure their kids under five have had their basic Hib vaccinations.

Dr. Anne Schuchat, director of the CDC’s National Center for Immunization and Respiratory Diseases, said the reported cases “is a terrible reminder to us that we can’t let our guard down. Bacteria and viruses are still out there, and if there is an opportunity, serious disease can come back; Parents who wondered whether Hib vaccination is really necessary need to know the disease is still around; it is a very dangerous disease and we have a vaccine that can protect children.”

Before any Hib vaccine was available, some 20,000 US children would get serious and sometimes fatal Hib infections every year, according to the CDC. Vaccination has cut that by 99 percent.

Two of the vaccines available for Hib infection, Merck & Co Inc.’ PedvaxHIB and COMVAX were recalled by the company in 2007 because production equipment might not have been properly sterilized. Both vaccines would return to the US market late this year, the company said.

For now, the only vaccine available for Hib infection is made by Sanofi Pasteur. Because of the shortage, the CDC has asked doctors to postpone the routine Hib vaccine booster doses typically given at age 12- to 15 months. However, the federal agency said there’s enough for children to get necessary doses at ages 2, 4 and 6 months.

Schuchat said the situation in Minnesota “may be happening elsewhere and hasn’t been reported.” That’s why she urged doctors to inform health authorities about any Hib infection they come across.

On the other hand, Minnesota state epidemiologist Ruth Lynfield, MD said the cases reported in Minnesota may be a result of the current shortage. “Providers did not have the vaccine in their offices.”