The UK health department announced that infants will receive a combined jab for diphtheria, tetanus, pertussis (whooping cough), polio and Hib (Haemophilus influenzae b) from September 2004. The five-in-one vaccine will replace the combined four-in-one diphtheria, tetanus, pertussis, Hib vaccine and separate oral polio vaccine currently used. But parent groups have raised concerns that the five-in-one vaccine to be given at two, three and four months of age may overload an infant's immune system, particularly if other vaccines are added to the schedule. At least the new pertussis component of the vaccine will finally be free from the mercury preservative thiomersal. But despite the link between mercury in vaccines and autism officials say the thiomersal is being removed to reduce environmental exposure to mercury. Still, there are many problems associated with these combination vaccines, and you can read about some of them in this past article.
New Scientist August 9, 2004