Those with long memories will have a feeling of deja vu when reading a recent report which admits that, yes, there may well be a link between contaminated polio vaccines, given routinely three or four decades ago, and rare cancers.

Between 1955 and 1963 large batches of polio vaccine were inadvertently contaminated with a monkey virus called simian virus 40 (SV40), which was found to cause cancer in laboratory animals. Scientists thought then that there was no risk to humans.

But recently, researchers have discovered evidence of SV40 in tissue samples from people stricken with rare childhood brain tumours, as well as bone and abdominal cancers (JAMA, 1997; 277: 873). This new evidence was recently considered by 250 scientists at the National Institutes of Health in the US where it was concluded that we could not rule out the role which SV40 may have played.

l A recent report has confirmed that the mixture of the Hib and DTP vaccines, originally thought to potentiate the Hib vaccine, in fact decreases its effectiveness (Lancet, 1996; 348: 1688). This is not news to some researchers however, who discovered nearly 10 years ago that a component of the DTP vaccine strikingly reduced the antibody response to Hib (J Paed, 198; 112; 695-702.)

For more information see the WDDTY Vaccination Handbook.