Whooping cough (pertussis) can be a serious respiratory infection. Vaccines made from killed whole Bordetella pertussis (B. pertussis) were developed, but they could cause serious and permanent nervous system disorders such as convulsions, encephalopathy and hypotonic-hyporesponsive episodes, as well as minor adverse events, such as anorexia, drowsiness, fever, irritability and fretfulness, prolonged crying, vomiting, injection site pain/redness/swelling/induration. This led to a fall in immunisation rates which resulted in an increase in the incidence of whooping cough.
New vaccines were developed which contain acellular purified B. pertussis antigens and have fewer adverse effects (less fever, irritability and injection site pain). This updated review of trials found that multi-component vaccines which contain acellular pertussis components are effective, with less adverse effects than whole-cell pertussis vaccines. One and two-component vaccines are less effective.