The makers of one of the Hib (Heamophilus Influenza) vaccines, Merck, have initiated a voluntary recall of certain batches of their vaccines. The CDC has a good page on the matter and details which specific vaccine batches are being removed from the market.
PedvaxHIB® [Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate)] and COMVAX® [Haemophilus b Conjugate (Meningococcal Protein Conjugate) and Hepatitis B (Recombinant) Vaccine] are the names of the specific recalls.
The recalled vaccines have been in use, within America, since April 2007. The reason for the recall is a precautionary measure due to an inability to assure total sterility of the vaccines. In total, about one million doses of vaccine are being removed from the market.
There have been no reports of adverse events associated with the vaccines in question and children already immunized with the vaccine lots in question do not need to be re-vaccinated.