Delayed immunisation increases risk of whooping cough

Immunisation for pertussis (whooping cough) is best given early and on time. Grant and colleagues (p 852) compared infants admitted to hospital in New Zealand for pertussis with those admitted for other acute respiratory illness. They found a fourfold increased risk of admission for pertussis associated with delays in each of the first, second, and third scheduled immunisations, or any combination of these. In New Zealand immunisation is given at 6 weeks, 3 months, and 5 months, whereas in Britain the schedule dictates immunisation at 2, 3, and 4 months. In an accompanying commentary (p 853), Berger says that unlike typhoid, diphtheria, and tetanus, whooping cough is endemic and can cause serious illnesses in children. These can be offset by delivering immunisations on time.