1 00:00:08,870 --> 00:00:14,350 To protect people against serious infectious diseases, 2 00:00:14,350 --> 00:00:18,070 children are vaccinated in the Netherlands from 2 months of age. 3 00:00:18,070 --> 00:00:23,440 One of those diseases is pertussis. Pertussis is caused by a bacterium and can lead to an 4 00:00:23,440 --> 00:00:26,439 acute and serious respiratory infection. 5 00:00:26,439 --> 00:00:30,610 The bacterium is spread by coughing and can result in weeks or even in months of 6 00:00:30,610 --> 00:00:34,540 prolonged coughing episodes which are very exhaustive for children. 7 00:00:34,540 --> 00:00:39,100 Not, or not entirely, vaccinated babies are extra vulnerable, 8 00:00:39,100 --> 00:00:43,350 and when they are infected, they are at risk to be admitted to the intensive care. 9 00:00:43,350 --> 00:00:49,620 Despite vaccination, the number of pertussis cases in the Netherlands increased since 1996, 10 00:00:49,620 --> 00:00:52,700 with the largest epidemic in 2012. 11 00:00:52,700 --> 00:00:58,110 In other countries, this increase in pertussis notification is also reported. 12 00:00:58,110 --> 00:01:01,750 The age at which pertussis prevalence is highest in the Netherlands, 13 00:01:01,750 --> 00:01:05,659 was in 2001 in children 4 to 6 years of age. 14 00:01:05,659 --> 00:01:09,420 To protect this group a booster vaccination against pertussis was 15 00:01:09,420 --> 00:01:13,009 introduced in 2001 for children 4 years of age. 16 00:01:13,009 --> 00:01:17,679 After this booster vaccination, the pertussis prevalence shifted to children 17 00:01:17,679 --> 00:01:19,579 8 to 15 years of age. 18 00:01:19,579 --> 00:01:23,759 The number of reported pertussis cases in adults increased as well. 19 00:01:23,759 --> 00:01:26,780 Older children can still suffer from pertussis. 20 00:01:26,780 --> 00:01:32,289 In some countries, like Germany, children aged 9 till 11 are being vaccinated with 21 00:01:32,289 --> 00:01:35,130 an extra pertussis vaccine to protect this age group. 22 00:01:35,130 --> 00:01:40,289 Whether this booster vaccination at 9 years of age provides long-term protection, 23 00:01:40,289 --> 00:01:44,929 is yet unclear. The RIVM will develop a study to investigate the effect of 24 00:01:44,929 --> 00:01:46,350 a booster vaccination against 25 00:01:46,350 --> 00:01:51,530 pertussis in children 9 years of age. By vaccinating 9 year old children in this 26 00:01:51,530 --> 00:01:53,079 study against pertussis, 27 00:01:53,079 --> 00:01:56,189 three points will be investigated. 28 00:01:56,189 --> 00:02:00,009 1, determine the level of protection against pertussis by vaccination. 29 00:02:00,009 --> 00:02:05,109 2, assess if these children are better and prolonged protected against pertussis 30 00:02:05,109 --> 00:02:09,630 and 3, evaluate on the long-term if such an extra vaccination can contribute 31 00:02:09,630 --> 00:02:13,160 to a decline in pertussis transition to unvaccinated babies.