ATLANTA (AP) -- Merck is recalling about a million doses of a childhood vaccine. The move was made after testing showed a sterilization problem at its Pennsylvania plant.


Merck is not aware of any harm to children who received the vaccine, known as Hib, which prevents meningitis and pneumonia.


The vaccine is a three-dose shot recommended for all children under 5 and is usually given to infants starting at two months old.