Page 12 - Preventing pertussis in early infancy - Visser

Chapter 1
Chapter 1
worldwide (Broutin et al. 2005, Plotkin et al. 2018). Many factors have been suggested to have contributed to the pertussis resurgence, such as more awareness, better diagnostics, waning immunity, bacterial changes in the circulating pertussis strains (Cherry 2012, Mooi et al. 2014), and, with increasing frequency in recent years, vaccine hesitancy (Phadke et al. 2016).
In the Netherlands, a higher baseline incidence of reported pertussis cases was observed from the 1996-1997 pertussis epidemic onwards with epidemic peaks every 2-3 subsequent year (Figure 1.1). At the same time, the age distribution of pertussis cases seemed to shift towards the older age groups of adolescents and adults. In 1997, as a reaction to the pertussis resurgence, the Dutch National Immunisation Programme (NIP) switched back to the more potent whole-cell vaccination. The vaccination schedule was adapted a few times since then, in response to the epidemiological changes in the years that followed. In 2005, whole-cell vaccination was replaced by acellular pertussis vaccination. The most recent schedule for the Dutch NIP is shown in Figure 1.2., where the acellular pertussis vaccine is combined with the vaccines against diphtheria, tetanus, poliomyelitis, haemophilus influenzae type B and hepatitis B. Despite the changes in the NIP, the incidence among infants continues to be higher than the incidence among children in other age groups (see Figure 1.3).
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