An injection of perspective
'Chaos over 5-in-1 jab' declared the UK Daily Mail, reporting that the government plans to replace an existing four-in-one jab, protecting against diptheria, whooping cough, Hib and tetanus, with a new one that adds protection against polio. The new vaccine will also not contain the preservative thiomersal, a mercury compound, which has been linked to autism by studies in the United States - leading to suggestions that the current vaccine is not safe. Campaigners also raised fears of immune system overload in infants coping with five different vaccines at once. Jackie Fletcher, founder of the support group Justice, Awareness and Basic Support (JABS), told the Guardian: 'Increasing the combinations increases the potential for an adverse reaction and restricts choice for parents.'
There are two panics here. The first is that mercury in the old vaccine, in the form of thiomersal, is harmful. The evidence against thiomersal is based on reports condemned by the American Academy of Paediatrics as containing 'numerous conceptual and scientific flaws, omissions of fact, inaccuracies and misstatements'.
The amount of mercury involved is so tiny that it simply could not be toxic, even to an infant. There is no evidence that it is harmful. It is not used in the new vaccine simply because it is incompatible with the polio element that has been added. However, by even implying that vaccines containing mercury should be withdrawn on a precautionary basis, the government has lent credence to the notion that thiomersal could be harmful.
The second panic is that the immune system of infants could be overloaded by a new multiple vaccine. This is similarly without substance. Newborn babies face a large number of potential infections, even in the process of being born. To counter this they already have the capability to deal with many different threats, a capability which develops further within a few days of birth. On the other hand, immune responses to some infections, like Hib, are much weaker in babies than they are in adults. For that reason, the vaccines used are specially designed to encourage immunity by stimulating well-developed parts of the immune system instead. This is also the reason why early vaccination is very important.
A review published in the journal Pediatrics concludes: 'Current studies do not support the hypothesis that multiple vaccines overwhelm, weaken, or "use up" the immune system. On the contrary, young infants have an enormous capacity to respond to multiple vaccines, as well as to the many other challenges present in the environment.'
While it is assumed that multiple vaccines must be more harmful, developments in protein chemistry mean that all the usual vaccines taken today, 11 in all, use fewer immunity-triggering proteins than just one vaccine (smallpox) did in the past. It seems that problems are found even where there has been progress.
Any conceivable harm caused by these vaccines is far outweighed by the harm done by the diseases they prevent. As Jennie Bristow notes on
spiked, we can fret about the slim possibility of vaccine damage precisely because of the remarkable success of the vaccination campaign. What this debate requires is an injection of perspective.
Doctors try to head off new vaccine row,
Guardian, 10 August 2004
Addressing parents' concerns: do multiple vaccines overwhelm or weaken the infant's immune system?,
Pediatrics, 1 January 2002 (pdf format)
Three cheers for the five-in-one jab, by Jennie Bristow,
spiked, 10 August 2004
First published on
spiked's
Don't panic page