The US Centers for Disease Control and Prevention (CDC), has asked doctors to defer the final booster dose of the childhood Haemophilus influenzae type b vaccine (Hib b vaccine) because of a possible problem with supplies.
However, children at high risk of Hib, which causes serious bacterial infections, including meningitis and pneumonia, should continue to receive the booster shot which is given at age 12 to 15 months.
High risk children includes those with cancer, sickle cell disease, or HIV as well as American Indian and Native Alaskan children.
There is likely to be a short term shortage of Hib b childhood vaccines in the US this year. Last week, the drug company Merck announced it was recalling over 1 million doses of its Hib PedvaxHIB and Comvax vaccines following a potential breach of sterilization procedure at its Pennsylvania factory.
The recall is a precaution said the company, and no contaminated vaccines were found in quality sampling of factory shipments.
Merck fills about half of the annual US demand for Hib b vaccine, the other half being filled by Sanofi Aventis. However, according to the CDC, Sanofi Aventis cannot immediately fill the gap left by the Merck recall, hence the need to prioritize this year’s vaccination programme until the full demand can be met again.
When supplies are restored, doctors should go ahead and give the booster shot to the children who were deferred said the CDC.
The CDC recommends that all American children under 5 receive the vaccine. The first dose is given at 2 months, the second at 4 months and the final one, the booster, at 12 to 15 months.
According to the CDC, Hib used to be the leading cause of bacterial meningitis in children under 5 years old, and it is still a leading cause of bacterial pneumonia deaths in children.
During the 1980s, the incidence of Hib b was between 40 and 100 per 100,000 under 5s in the US, but since routine administration of the vaccine in the US since 1990, the incidence has dropped to under 2 per 100,000 children.
In developing countries, where the vaccine is not routinely given, Hib remains a major cause of lower respiratory tract infections in babies and young children.
The CDC advice to doctors to defer the booster for those children who are not not at high risk was taken in consultation with various bodies, including the American Academy of Family Physicians, the Advisory Committee on Immunization Practices, and the American Academy of Pediatrics.
The Hib vaccine is not the annual flu vaccine which is normally given to adults against seasonal influenza.
Sources: CDC, WebMD, Reuters, Associated Press.
Written by: Catharine Paddock