Pertussis immunisationBMJ 2003; 326 doi: https://doi.org/10.1136/bmj.326.7394.853 (Published 19 April 2003) Cite this as: BMJ 2003;326:853
Tolerance for pertussis (whooping cough) immunisation is highest when given early, and on time. Since the disease is most severe in young infants, early completion of immunisation is critical. Pertussis immunisation in the United Kingdom is presently given at 2, 3, and 4 months. This “accelerated” course was introduced in 1990, and there is good direct evidence that the early schedule is tolerated better than the previous (later) schedule.1 This negates the idea that parents sometimes have that babies “cope” better with vaccination when they are older and bigger. Efficacy of the pertussis vaccine used in England and Wales is high although it wanes with increasing age.2
If primary immunisation is delayed or not completed, child health will be compromised. While typhoid, diphtheria, and tetanus are not endemic in the United Kingdom, pertussis is present and does cause morbidity and mortality. Pertussis causes most morbidity before the age of 8 weeks (before immunisation begins). The number of hospital admissions for pertussis in all ages was 853 in 1999 (E Miller, personal communication, 2001) and almost half of these were in children under 3 months of age. Without the accelerated course, these rates would be higher, and overall protection depends on the course being completed.
The youngest babies are probably getting pertussis from older children, who usually suffer only a mild illness, and for this reason preschool boosters for pertussis were introduced from October 2001. One study that looked at whole cell pertussis preschool boosters found that while antibody responses were high, the rate of reactions increased,3 whereas another study found that acellular pertussis boosters result in good immunogenicity and do not produce more reactions.4