Whooping cough vaccine ineffectiveA study from the USA confirms what we already knew: that the acellular pertussis (whooping cough) vaccine is not very effective at preventing whooping cough. This is why a 6th dose of the vaccine – given to children aged 11-12 – has recently been introduced in the USA. However the introduction of this extra dose has done little to reduce the number of cases of whooping cough in children. A large outbreak of whooping cough gave doctors the opportunity to calculate exactly how effective the vaccine is by comparing the number of cases in vaccinated children compared to the number of cases in unvaccinated children. The overall effectiveness was around 50% which is really rather poor when compared with most other vaccines. Of particular concern was the very low effectiveness of only 24% in children aged between 8 and 12 years. This is because, even after 5 doses of vaccine given to children by 6 years of age, any protective effect obtained is short lasting and wears off after only a few years. Though the introduction of the pre-adolescent pertussis booster has reduced the number of cases of pertussis in teenagers, the number of cases in younger children continues to rise.
Whooping cough remains a common illness that many children, including those fully vaccinated, will catch. Being fully vaccinated is likely to reduce the severity of the illness which, though rarely life-threatening in developed countries, can be unpleasant and distressing particularly in infants. However, unless we develop a more effective vaccine, the only way that we will be able to really control the disease is probably to vaccinated everyone every 5-10 years throughout life - an unattractive and unrealistic proposition.
Added 17 April 2012