The ordinary whole-cell pertussis vaccine is acknowledged to be the deadliest of all the vaccines. The US National Vaccine Compensation Program (which has paid out over $1 billion to vaccine-damaged children) obliges drug companies that produce vaccines to contribute to the program by paying an excise tax on each dose of vaccine, based on likely risk.

In 1997, the latest figures available to WDDTY, the DTP vaccine was taxed at the highest rate per dose - $4.56 - compared with $0.29 for polio and $0.06 for DT (without pertussis). Only the MMR vaccine, at $4.44 per dose, approaches the DPT in ‘taxation’. This is tacit acknowledgement by the government that the pertussis vaccine carries the highest risk of them all.

However, no randomised placebo-controlled trials of whole-cell vaccine have been performed since the 1950s, when diagnostic methods were different. Indeed, in the early 1990s, the Institute of Medicine (IOM), which spent 20 months studying all the available data on vaccinations, confirmed that no controlled clinical trials have ever been conducted to rule out whether the vaccine can cause chronic neurological damage, blood disorders, juvenile diabetes, Guillain-Barré paralysis and learning disabilities. With the most controversial vaccine in history, most questions about safety have never been asked.

* The only large-scale study ever conducted in the US, at University of California at Los Angeles in 1979, found that one in 875 doses of DPT is followed by convulsions, or an episode of shock or collapse, leading to death in the case of two babies (Pediatrics, 1981; 68: 650-60). As for brain damage, a Swedish study showed a rate of brain damage or death of one in 17,000 children (BMJ, 1967; 4: 320-3).

* The main study supposedly of safety, the British National Childhood Encephalopathy Study, showed that one in 110,000 DPT shots causes a serious neurological reaction and one in 310,000 shots causes brain damage or death (DHSS, Whooping Cough: Reports from the Committee on the Safety of Medicines and the Joint Committee on Vaccination and Immunisation, HMSO, 1981). As children receive three shots apiece, the true figures may be that one in 30,000 children will have a neurological reaction and one in 100,000 children will be killed or brain-damaged by the jab. These figures may also be on the low side, as high-risk children were excluded from the study as well as any child who was not hospitalised or experienced convulsions of less than 30 minutes’ duration.

The IOM report concluded that:
* the triple shot definitely causes anaphylactic shock and extended periods of inconsolable crying or screaming
* evidence is consistent with a causal relationship between acute encephalitis (inflammation of the brain) and shock and unusual shock-like (hypotonia/hyporesponsive) reactions, causing total collapse (Stratton K, Adverse Events Associated with Childhood Vaccines; Evidence Bearing on Causality, Washington, DC: National Academy Press, 1993).

Other evidence shows:
* the pertussis vaccine may cause lasting brain damage (J Oklahom St Med Assoc, 1996; 89: 135-8). The IOM estimates 105 cases per million vaccinations
* premature infants given the vaccine have episodes of apnoea, where they stop breathing (J Pediatr, 1997; 130: 746-51)
* according to a 1992 reanalysis of the Childhood Encephalopathy Study, the risk of encephalitis with the vaccine have been grossly underestimated. The new analysis estimates a four-fold increase in the estimated risk of encephalitis (Dev Med Child Neurol, 1993; [Suppl 68] 35: 1-118)
* the DPT increases the risk of febrile seizure fivefold on the day of vaccination (N Engl J Med, 2001, 345: 656-61)
* children vaccinated with pertussis vaccine are six times more likely to develop asthma (JAMA, 1994; 272: 592-3).