Whooping cough (pertussis) can be a serious respiratory infection. Vaccines made from killed whole Bordetella pertussis (B. pertussis) were developed but they could cause severe neurologic 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, and 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. Acellular pertussis (aP) vaccines (containing purified or recombinant B. pertussis antigens) were developed in the hope that they would be as effective but less reactogenic than the whole-cell pertussis (wP) vaccines.
This updated review included six efficacy trials with a total of 46,283 participants and 52 safety trials with a total of 136,541 participants. The efficacy of multi-component (≥ three) acellular vaccines varied from 84% to 85% in preventing typical whooping cough (characterised by 21 or more consecutive days of paroxysmal cough with confirmation of B. pertussis infection by culture, appropriate serology or contact with a household member who has culture-confirmed pertussis) and from 71% to 78% in preventing mild pertussis disease (characterised by seven or more consecutive days of cough with confirmation of B. pertussis infection by culture or appropriate serology). One- and two-component acellular vaccines were less effective. Most systemic and local adverse events were significantly less common with aP than with wP vaccines for the primary series as well as for the booster dose. This review found that multi-component vaccines which contain three or more aP components are effective, with less adverse effects than wP vaccines.