Respiratory syncytial virus vaccination during pregnancy for improving infant outcomes.

Background: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections (LRTIs) in infants. Maternal RSV vaccination is a preventive strategy of great interest, as it could have a substantial impact on infant RSV disease burden. In recent years, the clinical development of maternal RSV vaccines has advanced rapidly.

Comparison of the tolerability of newly introduced childhood vaccines in the Netherlands.

Unlabelled: In 2011, the 7-valent conjugated pneumococcal vaccine (PCV7) was replaced by the 10-valent vaccine (PCV10) and universal hepatitis B vaccination has been introduced in the Netherlands. A questionnaire study was conducted to assess the tolerability of DTaP-IPV-Hib + PCV7 (PCV7-cohort), DTaP-IPV-Hib + PCV10 (PCV10-cohort), and DTaP-IPV-Hib-HepB + PCV10 (HepB-cohort). Parents were asked to report in questionnaires local reactions and systemic adverse events (AEs) before and after vaccination of their infant at 2, 3, 4, and 11 months of age.

The Use of Innovative Two-Component Cluster Analysis and Serodiagnostic Cut-Off Methods to Estimate Prevalence of Pertussis Reinfections.

Bordetella pertussis circulates even in highly vaccinated countries affecting all age groups. Insight into the scale of concealed reinfections is important as they may contribute to transmission. We therefore investigated whether current single-point serodiagnostic methods are suitable to estimate the prevalence of pertussis reinfection.

Tolerability of Early Measles-Mumps-Rubella Vaccination in Infants Aged 6-14 Months During a Measles Outbreak in The Netherlands in 2013-2014.

Background: In 2013-2014, a measles outbreak spread through the Netherlands. To protect young infants, measles-mumps-rubella (MMR) vaccination was offered to those aged 6-14 months in municipalities with routine first-dose MMR vaccine coverage of <90%. We assessed the tolerability of this early administration of MMR vaccine.

Effect of vaccinations on seizure risk and disease course in Dravet syndrome.

Objective: To study the effect of vaccination-associated seizure onset on disease course and estimate the risk of subsequent seizures after infant pertussis combination and measles, mumps, and rubella (MMR) vaccinations in Dravet syndrome (DS).

Methods: We retrospectively analyzed data from hospital medical files, child health clinics, and the vaccination register for children with DS and pathogenic SCN1A mutations. Seizures within 24 hours after infant whole-cell, acellular, or nonpertussis combination vaccination or within 5 to 12 days after MMR vaccination were defined as "vaccination-associated.

Etiologies for seizures around the time of vaccination.

Objectives: This study was an assessment of the incidence, course, and etiology of epilepsy with vaccination-related seizure onset in a population-based cohort of children.

Methods: The medical data of 990 children with seizures after vaccination in the first 2 years of life, reported to the National Institute for Public Health and Environment in the Netherlands in 1997 through 2006, were reviewed. Follow-up data were obtained of children who were subsequently diagnosed with epilepsy and had had seizure onset within 24 hours after administration of an inactivated vaccine or 5 to 12 days after a live attenuated vaccine.

Estimation of the serial interval of pertussis in Dutch households.

Increasing incidence has led to the re-appearance of pertussis as a public health problem in developed countries. Pertussis infection is usually mild in vaccinated children and adults, but it can be fatal in infants who are too young for effective vaccination (≤3 months). Tailoring of control strategies to prevent infection of the infant hinges on the availability of estimates of key epidemiological quantities.

Low varicella-related consultation rate in the Netherlands in primary care data.

Background: In the Netherlands, a relatively low varicella disease burden compared to other European countries is observed within routine surveillance. To validate this, we estimated the varicella-related consultation rate using The Integrated Primary Care Information database.

Methods: In this retrospective cohort study, varicella patients in 2006-2008 were identified by the International Classification of Primary Care (A72) and free text in the electronic medical records, and manually reviewed to be categorised as 'varicella' or 'probable varicella'.

Delayed start of diphtheria, tetanus, acellular pertussis and inactivated polio vaccination in preterm and low birth weight infants in the Netherlands.

Background: It is recommended that preterm (PT) and low birth weight infants be vaccinated according to standard guidelines. We studied the timeliness of the first diphtheria, tetanus, acellular pertussis and inactivated polio vaccination in the Netherlands, by gestational age (GA) and birth weight (BW).

Methods: We included all vaccinated children born during 2006-2010.

Pertussis in the Netherlands, is the current vaccination strategy sufficient to reduce disease burden in young infants?

Background: Pertussis has resurged in the Netherlands since 1996. Several measures, i.e.

Prevalence of SCN1A-related dravet syndrome among children reported with seizures following vaccination: a population-based ten-year cohort study.

Objectives: To determine the prevalence of Dravet syndrome, an epileptic encephalopathy caused by SCN1A-mutations, often with seizure onset after vaccination, among infants reported with seizures following vaccination. To determine differences in characteristics of reported seizures after vaccination in children with and without SCN1A-related Dravet syndrome.

Methods: Data were reviewed of 1,269 children with seizures following immunization in the first two years of life, reported to the safety surveillance system of the Dutch national immunization program between 1 January 1997 and 31 December 2006.

Acceptance of vaccination during pregnancy: experience with 2009 influenza A (H1N1) in the Netherlands.

Objectives: In 2009, the Dutch government advised pregnant women to get vaccinated against influenza A (H1N1). A study was set up to gain insight into vaccination coverage and reasons why pregnant women seek vaccination or not.

Methods: We invited 14,529 pregnant women to complete an internet survey on vaccination during pregnancy in general and against 2009 influenza A (H1N1).

Guillain-Barré syndrome: background incidence rates in The Netherlands.

Guillain-Barré syndrome (GBS) is a (sub)acute polyradiculoneuropathy, which may occur following immunization. To interpret the occurrence of GBS after introduction of large-scale immunization programmes, it is important to define recent background incidence rates (IRs) of GBS. We used a general practitioner electronic medical record database to assess age-specific GBS IRs between 1996 and 2008 in The Netherlands.

Two doses of pandemic influenza A(H1N1) vaccine: tolerability in healthy young children in the Netherlands.

During the 2009 influenza pandemic, children aged 6 months up to and including 4 years, without chronic illness, were vaccinated with two doses of Pandemrix(®) through mass vaccination in the Netherlands. During the vaccination campaign a warning was issued about fever after the second dose of Pandemrix(®). Therefore, we investigated the tolerability of both doses Pandemrix(®) in these children.

Pertussis in infancy and the association with respiratory and cognitive disorders at toddler age.

Pertussis in unvaccinated infants can run a severe course and is often accompanied by complications. In this pilot study, we studied whether there is an association between pertussis hospitalisation in infancy and, respiratory symptoms, growth and cognitive development in early childhood. A group of 89 children aged 13-45 months and hospitalised for laboratory confirmed pertussis within the first six months of their life were compared with 172 children without a history of pertussis.

Comparison of the tolerability of an acellular pertussis-containing vaccine given as the fifth booster dose in differently primed children.

Background: In 2005, an acellular pertussis-containing DTP-IPV-Hib vaccine for infants replaced the whole-cell combination vaccine in the National Immunisation Programme of the Netherlands. From 2008 onwards, an increase in local reactions to boosters was seen in an enhanced passive reporting system of adverse events following immunisation.

Method: A cross-sectional study was conducted to assess the difference in tolerability of a DTaP-IPV booster in four-year-old children primed in infancy with either three doses DTaP-IPV-Hib (aP-primed) or three doses of DTwP-IPV-Hib (wP-primed).

Hospitalization due to varicella in the Netherlands.

Background: In the Netherlands, incidence of physician's consultations and hospitalizations for varicella is low compared to other countries. Better knowledge about the severity of varicella among Dutch hospitalized patients is needed. Therefore, a medical record research was conducted among hospitalized patients with diagnosis varicella.

Parental reports of adverse events following simultaneously given dT-IPV and MMR vaccines in healthy 9-year-old children.

In the Netherlands, children at 9 years of age receive a booster dT-IPV together with their second measles, mumps, and rubella (MMR) vaccination within the national immunization program. Safety is monitored continuously by enhanced passive surveillance. This population-based study was conducted to obtain more information on adverse events after vaccination at 9 years of age.

[Safety of the bivalent human papillomavirus vaccine--results following administration of more than 192,000 doses].

Aim: To study the safety profile of the bivalent human papillomavirus (HPV) vaccine following administration of a first dose to 192,119 13-16-year-old girls in the context of a catch-up campaign.

Design: Descriptive.

Methods: The safety of the HPV campaign underwent surveillance in three ways: via a spontaneous reporting system, whereby anyone could report a possible undesirable effect; following completion and validation a diagnosis was made and the causal relationship with the vaccination assessed.

Reactogenicity of infant whole cell pertussis combination vaccine compared with acellular pertussis vaccines with or without simultaneous pneumococcal vaccine in the Netherlands.

Background: In addition to the routine enhanced passive safety surveillance of the Dutch National Vaccination Programme, RIVM (National Institute for Public Health and the Environment) started a large questionnaire study enrolling approximately 53,000 children from December 2003 until September 2007.

Aim: We intended to establish accurate frequency estimates for several more severe adverse events and to compare the incidence rates of three different infant vaccines that were used consecutively.

Methods: Whole cell pertussis (wP) DTP-IPV-Hib vaccine (NVI) was replaced by acellulair pertussis (aP) in 2005, first Infanrix-IPV-Hib (GSK) followed by Pediacel (Sanofi) in 2006.

Discolored leg syndrome after vaccination--descriptive epidemiology.

Discoloration of the leg following vaccination is a relatively unknown entity. We carried out a study of discolored leg syndrome (DLS) during a 10-year consecutive period with the objective of characterizing DLS in infants following vaccination received in the Dutch National Vaccination Program as well as its occurrence and association with different vaccines. Discolored leg syndrome was defined as an even or patchy red, blue or purple discoloration of the leg(s) and/or leg petechiae with or without swelling.

The effect of age and dose number on the risk of collapse (hypotonic-hyporesponsive episode) after pertussis vaccination.

The Netherlands vaccination schedule has been advanced by 1 month. The reporting rate of collapse or hypotonic-hyporesponsive episode increased from 5.2 [95% confidence interval (CI): 4.

Assessing the introduction of universal human papillomavirus vaccination for preadolescent girls in The Netherlands.

A persistent infection with human papillomavirus (HPV) is a prerequisite for the development of cervical cancer. Clinical trials with HPV-vaccines have been very successful in preventing persistent HPV16/18 infections, the two most oncogenic HPV-genotypes. We assessed the introduction of universal HPV-vaccination for preadolescent girls in the Dutch National Immunization Programme.

Performance of the Brighton collaboration case definition for hypotonic-hyporesponsive episode (HHE) on reported collapse reactions following infant vaccinations in the Netherlands.

We reviewed collapse (sudden onset of pallor, limpness and hyporesponsiveness) following the first infant (DPTP+Hib) vaccination reported to the enhanced passive surveillance system of the Netherlands in 1994-2003. All 1303 reports identified by the current RIVM (National Institute for Public Health and Environment) case definition were captured by the Brighton Collaboration (BC) case definition, with in 17 (1.3%) reports insufficient information.