Adolescent and parental decision-making for the MenACWY vaccination: influential predictors and parental-adolescent differences among households in the Netherlands.

BACKGROUND: Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW). Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated targeting adolescents. This study aimed to gain insight into what factors played a role in the decision-making process regarding the MenACWY vaccination. The focus was on the differences in the decision-making of parents and adolescents in order to assess what factors influence the decisions made. METHODS: An online questionnaire was offered to adolescents and one of their parents. We used random forest analyses to determine which factors best predict the outcome of the MenACWY vaccination decision. We carried out ROC (receiver-operator characteristics) analyses to confirm the predictive value of the variables. RESULTS: Among parents several factors stand out, centring on the process of the decision, their attitude about the MenACWY vaccination, trust in the vaccination, and ideas of important people around them. Among adolescents the three stand-out predictors are the ideas of important people around them, the process of the decision and trust in the vaccination. Parents have prominent influence in the decision-making, while the adolescent's influence in the household decision-making is more limited. Adolescents tend to be less engaged and spend less time thinking about the decision compared to parents. Opinions of parents and adolescents from the same households concerning the factors that are influential do not differ a lot in the final decision-making. CONCLUSIONS: Information about MenACWY vaccination might be mainly addressed to the parents of the adolescents and whereby the dialogue about MenACWY vaccination between parents and adolescents will be stimulated. With regard to the predictor trust in vaccination, raising the frequency of use of certain sources, especially those deemed very reliable among households such as conversations with a GP or the provider of the vaccination (GGD/JGZ), might prove a useful strategy to solidify vaccination uptake numbers.

How to increase awareness of additional vaccinations; the case of maternal pertussis vaccination.

BACKGROUND: Effective and safe vaccines are available outside national immunization programs (NIP). Increased awareness and vaccine uptake can improve public health. Before the inclusion of maternal pertussis vaccination (MPV) in the Dutch NIP in December 2019, extra communication efforts were undertaken. Here we examine the success of these efforts, investigating women's awareness of and their decision-making process regarding MPV. METHODS: Between December 2018 and January 2019, one year before the introduction of MPV in the NIP, and about three years after MPV was recommended by the Dutch Health Council, pregnant and non-pregnant women (i.e. child younger than two years) were invited to fill out an online questionnaire. Participant's decision-making processes regarding MPV were assessed with an adapted Precaution Adoption Process Model (PAPM), including stages of awareness, engagement, information-seeking, and vaccination behaviour. Furthermore, factors related to the decision-making process were examined. RESULTS: In total, 942 women were included, of whom 62% were non-pregnant. Most of the pregnant and nonpregnant women were aware of MPV during pregnancy (respectively 69 and 56%). Most aware women had heard about MPV through their midwife and the Public Health Institute (PHI) website. Women unaware of MPV reported a need for information, preferably from their midwives. Most aware women felt MPV was important to them (88%) and were classified as "engaged". Of the eligible and "engaged" pregnant women, 58% were vaccinated, versus 38% of "engaged" non-pregnant women. CONCLUSIONS: As the most preferred and trusted source of information, midwives are essential to increasing awareness of MPV. The PHI website is considered to be a reliable information source and is often consulted. To increase awareness, appropriate healthcare workers should be encouraged to actively inform target groups about available, additional vaccinations.

Determinants of HPV-vaccination uptake and subgroups with a lower uptake in the Netherlands.

BACKGROUND: In the Netherlands, the HPV-vaccine uptake was 52% during the 2009 catch-up campaign (birth cohorts 1993-1996). This increased to 61% in the regular immunization program (birth cohorts 2000-2001). However for birth cohorts 2003-2004 the uptake declined to 45.5%. With this study we aimed to gain insight into social, economic and cultural determinants that are associated with HPV-vaccination uptake and which subgroups with a lower HPV-vaccination uptake can be identified. In addition, we investigated whether the influence of these factors changed over time. METHODS: To study the determinants of HPV-vaccine uptake we performed a database study using different aggregation levels, i.e. individual level, postal code level and municipality level. All Dutch girls who were invited for HPV-vaccination through the National Immunization Program in the years 2012, 2014 and 2017 (i.e. birth cohorts 1999, 2001 and 2004, respectively) were included in the study population. We conducted multilevel logistic regression analyses to analyze the influence of the determinants on HPV-vaccination uptake, taking into account that the delivery of HPV-vaccine was nested within municipalities. RESULTS: Results showed that in particular having not received a MMR-vaccination, having one or two parents born in Morocco or Turkey, living in an area with lower socioeconomic status and higher municipal voting proportions for Christian political parties or populist parties with liberal-conservative views were associated with a lower HPV-vaccination uptake. Besides some changes in political preferences of the population and changes in the association between HPV uptake and urbanization level we found no clear determinants which could possibly explain the decrease in the HPV-vaccination uptake. CONCLUSIONS: In this study we identified current social, economic and cultural determinants that are associated with HPV-vaccination uptake and which low-vaccination subgroups can be identified. However, no clear determinants were found which could explain the decrease in the HPV-vaccination uptake. Tailored information and/or consultation for groups that are associated with a lower HPV-vaccination uptake might help to increase the HPV-vaccination uptake in the future.

The tip of the iceberg: incompleteness of measles reporting during a large outbreak in The Netherlands in 2013-2014.

Measles is a notifiable disease, but not everyone infected seeks care, nor is every consultation reported. We estimated the completeness of reporting during a measles outbreak in The Netherlands in 2013-2014. Children below 15 years of age in a low vaccination coverage community (n = 3422) received a questionnaire to identify measles cases. Cases found in the survey were matched with the register of notifiable diseases to estimate the completeness of reporting. Second, completeness of reporting was assessed by comparing the number of susceptible individuals prior to the outbreak with the number of reported cases in the surveyed community and on a national level.We found 307 (15%) self-identified measles cases among 2077 returned questionnaires (61%), of which 27 could be matched to a case reported to the national register; completeness of reporting was 8.8%. Based on the number of susceptible individuals and number of reported cases in the surveyed community and on national level, the completeness of reporting was estimated to be 9.1% and 8.6%, respectively. Estimating the completeness of reporting gave almost identical estimates, which lends support to the credibility and validity of both approaches. The size of the 2013-2014 outbreak approximated 31 400 measles infections.

Under-vaccinated groups in Europe and their beliefs, attitudes and reasons for non-vaccination; two systematic reviews.

BACKGROUND: Despite effective national immunisation programmes in Europe, some groups remain incompletely or un-vaccinated ('under-vaccinated'), with underserved minorities and certain religious/ideological groups repeatedly being involved in outbreaks of vaccine preventable diseases (VPD). Gaining insight into factors regarding acceptance of vaccination of 'under-vaccinated groups' (UVGs) might give opportunities to communicate with them in a trusty and reliable manner that respects their belief system and that, maybe, increase vaccination uptake. We aimed to identify and describe UVGs in Europe and to describe beliefs, attitudes and reasons for non-vaccination in the identified UVGs. METHODS: We defined a UVG as a group of persons who share the same beliefs and/or live in socially close-knit communities in Europe and who have/had historically low vaccination coverage and/or experienced outbreaks of VPDs since 1950. We searched MEDLINE, EMBASE and PsycINFO databases using specific search term combinations. For the first systematic review, studies that described a group in Europe with an outbreak or low vaccination coverage for a VPD were selected and for the second systematic review, studies that described possible factors that are associated with non-vaccination in these groups were selected. RESULTS: We selected 48 articles out of 606 and 13 articles out of 406 from the first and second search, respectively. Five UVGs were identified in the literature: Orthodox Protestant communities, Anthroposophists, Roma, Irish Travellers, and Orthodox Jewish communities. The main reported factors regarding vaccination were perceived non-severity of traditional "childhood" diseases, fear of vaccine side-effects, and need for more information about for example risk of vaccination. CONCLUSIONS: Within each UVG identified, there are a variety of health beliefs and objections to vaccination. In addition, similar factors are shared by several of these groups. Communication strategies regarding these similar factors such as educating people about the risks associated with being vaccinated versus not being vaccinated, addressing their concerns, and countering vaccination myths present among members of a specific UVG through a trusted source, can establish a reliable relationship with these groups and increase their vaccination uptake. Furthermore, other interventions such as improving access to health care could certainly increase vaccination uptake in Roma and Irish travellers.

Predictors of possible exposure to rabies in travellers: A case-control study.

BACKGROUND: Timely administration of post-exposure prophylaxis (PEP) can prevent rabies. For non-vaccinated persons, PEP consists of multiple vaccinations and rabies immunoglobulin (RIG) on indication. Since RIG is scarce, the need for PEP could be restricted through preventing animal contact and pre-exposure vaccination. We aimed to identify determinants for possible rabies exposure among travellers to provide more targeted pre-travel advice. METHOD: A case-control study was performed. Cases were defined as persons with a possible rabies exposure (category II or III injury according to WHO classification guidelines) in a rabies endemic country. Controls did not report exposure during travel. Multivariable logistic regression was performed. RESULTS: 229 cases and 1427 controls were included. Predictors (p < 0.05) of possible rabies exposure were young age, male sex, travelling to Western or Southeastern Asia, visiting a monkey park, pet ownership, previously visited the same country and considering oneself an experienced traveller. Negative predictors were travelling for business, visiting friends and relatives, and fear of animals. CONCLUSIONS: Pre-travel advice should take the identified predictors into account to provide better targeted information and pre-exposure prophylaxis.

Mumps epidemic in orthodox religious low-vaccination communities in the Netherlands and Canada, 2007 to 2009.

We assessed the epidemiological characteristics of a mumps virus epidemic (genotype D) that occurred in the Netherlands between August 2007 and May 2009 and its association with a subsequent mumps outbreak in Canada. In the Netherlands, five data sources were used: notifications (only mandatory since the end of 2008) (56 cases), laboratory confirmation data (177 cases), a sentinel general practitioner (GP) database (275 cases), hospitalisation data (29 cases) and weekly virological reports (96 cases). The median age of cases in the notification, laboratory and GP databases ranged from 13 to 15 years. The proportion of cases that were unvaccinated ranged from 65% to 85% in the notification, laboratory and GP databases. Having orthodox Protestant beliefs was the main reason for not being vaccinated. In Canada, a mumps virus strain indistinguishable from the Dutch epidemic strain was detected between February and October 2008 in an orthodox Protestant community with historical and family links to the affected community in the Netherlands, suggesting that spread to Canada had occurred. Prevention and control of vaccine-preventable diseases among population subgroups with low vaccination coverage remains a priority.

Household decision-making for the MenACWY vaccination: How parents and adolescents deal with an adolescent vaccination decision.

OBJECTIVE: Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW), from 0.02 cases/100,000 people between 2010 and 2014 up to 0.5 cases/100,000 in 2017. Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated among adolescents. This study aimed to gain insight into the decision-making process within households regarding the MenACWY vaccination. The focus was on the differences in the decision-making process of parents and adolescents and of those that had accepted the MenACWY vaccination and those that had not, in order to assess how these types of decisions are made within households. METHOD: We conducted a total of 38 semi-structured interviews in 20 households (7 not vaccinated) with 20 parents and 18 adolescents (18 dyads) across The Netherlands concerning their decision-making process. Interview guides were constructed based on the Precaution Adaption Process (PAP) model. We performed thematic analysis using qualitative data analysis software (MAXQDA). RESULTS: Parents are the main actors in the household decision-making process regarding the MenACWY vaccination. Parents start their decision-making process before adolescents are even aware of the issue. Households in the study took different approaches in involving the adolescent in the decision-making, resulting in three styles of household decision-making: parents decide without the adolescent, parents involve the adolescent, or parents leave it up to the adolescent to decide. CONCLUSION: Parents influence adolescent reasoning, engagement and involvement during the MenACWY vaccination decision-making. And this is the case both among those that have accepted and rejected the MenACWY vaccination. Adolescent engagement with the MenACWY vaccination decision-making is either short-lived or non-existent. However, the moment offers opportunities to engage adolescents on vaccinations and decision-making, with parents as key figures to promote this.

A cost-utility analysis of antenatal screening to prevent congenital rubella syndrome.

In low vaccination coverage regions (LVR) in The Netherlands people often reject participation in the National Immunization Programme for religious reasons. During a rubella epidemic in 2004-2005, 32 pregnant women were notified with rubella, and 11 babies were born with defects related to maternal infection. This study presents a cost-utility analysis of a screening and vaccination programme for rubella focusing on three scenarios: (1) screening non-vaccinated pregnant women in LVR; (2) screening all pregnant women in LVR; (3) screening all non-vaccinated pregnant women in The Netherlands (including pregnant first-generation non-Western immigrant women). Cost-utility was estimated over a 16-year period which included two rubella outbreaks. Observed complications from the 2004-2005 epidemic were used to estimate average cost savings and quality-adjusted life-years (QALY) gained. The programme would be cost-effective (euro1100/QALY gained) when assuming an acceptability of vaccination of 20% in women belonging to orthodox protestant risk groups.

[Revised multidisciplinary guidelines 'Varicella'; broader indication for post-exposure prophylaxis]. / Herziene multidisciplinaire richtlijn 'Varicella'.

Post-exposure prophylaxis (PEP) with varicella zoster immunoglobulins (VZIG) should be administered as soon as possible after exposure to the virus, but always within ten days; in the previous guidelines this was within 96 hours. In cases of perinatal exposure, PEP with VZIG should be administered to neonates if the mother develops clinical chickenpox between seven days before delivery and seven days after delivery; in the previous guidelines this was between five days before delivery and two days after delivery. A new chapter on the treatment of chickenpox has been added to the guidelines.

[No scientific lower threshold for compulsory vaccination]. / Geen wetenschappelijke ondergrens voor verplicht vaccineren.

The national vaccination rate in young children in the Netherlands has decreased in recent years. This has led to social and political discussions, for instance about compulsory vaccination for children in child-care. The national commission on child-care and vaccination has advised that vaccination should be made compulsory when the rate of vaccination has declined to a pre-determined lower threshold, to be determined by the government. A frequently quoted lower threshold is 95%. The idea behind this is the concept of a critical vaccination rate, a threshold needed for elimination of an infection in a large, well-mixed population. In this article we argue why the critical vaccination rate does not offer a scientific basis for a lower threshold to the national vaccination rate.

[Guideline 'Needlestick injuries': risk assessment and post-exposure management in practice]. / Richtlijn 'Prikaccidenten': risicobeoordeling en postexpositiebeleid in de praktijk.

Guideline 'Needle stick injuries': risk assessment and post-exposure management in practice The objective of the national guideline 'Needle stick injuries' is to make the assessment of needle stick injuries more structured and uniform. The injury is classified as high risk or low risk according to the volume of blood transmitted. For high-risk injuries measures to prevent hepatitis B, hepatitis C and HIV infection have to be considered, whereas for low-risk injuries only measures to prevent hepatitis B. The need for post-exposure prophylaxis is determined by the victim's immunity to hepatitis B and the presence of hepatitis B virus, hepatitis C virus or HIV in the source person. Post-exposure prophylaxis against hepatitis B consists primarily of hepatitis B vaccination; hepatitis B immunoglobulin is added in the case of a high-risk injury with a hepatitis B positive source or a source belonging to a risk group for hepatitis B. In high-risk injuries the victim is tested for hepatitis C and HIV transmission (except in case of a seronegative source). Antiretroviral postexposure prophylaxis is advised for high-risk injuries with a HIV seropositive source or a source belonging to a risk group for HIV.

Cross-sectional study on factors hampering implementation of measles pre- and postexposure measures in Dutch hospitals during the 2013-2014 measles outbreak.

BACKGROUND: This study examined adherence to national recommendations on measles pre- and postexposure measures, including immunization of health care workers (HCWs) in Dutch hospitals, during a national outbreak of measles in The Netherlands. This study also investigated which hospital characteristics and organizational issues hamper implementation. METHODS: This was a cross-sectional survey among all general and academic hospitals in The Netherlands. An online structured questionnaire (48 questions) was administered. Analysis was performed using descriptive statistics and logistic regression. RESULTS: Of 88 hospitals, 70 (79.5%) were included. Of 68 hospitals, 48 (70.6%) assessed susceptibility to measles in HCWs. Of 70 hospitals, 61 (87.1%) offered vaccination to susceptible HCWs. Of 63 hospitals, 42 (66.7%) had postexposure policies consistent with national recommendations. Of 62 hospitals, 30 (48.4%) implemented all these measures, which is the minimum set of measures considered necessary to adequately prevent measles in HCWs. Logistic regression suggests that hospitals with several locations, hospitals with more employees, and hospitals where infectious disease experts designed infection prevention policies while occupational health experts implemented the policy less often implemented this minimum set of measures (P < .001, P < .01, and P < .001, respectively). CONCLUSIONS: During a national measles outbreak, most hospitals took measures to prevent measles in HCWs, but less than half implemented the minimum set of measures required. Implementation strategies in hospitals need to be improved, especially in large-sized hospitals and hospitals with several locations, and with respect to the assignment of responsibilities for infection prevention policies.

[Rubella epidemic in the Netherlands, 2004/'05: awareness of congenital rubella syndrome required]. / Rubella-epidemie in Nederland in 2004/'05: alertheid op congenitaal rubellasyndroom vereist.

Rubella is a public health problem due to the teratogenic effects associated with primary rubella infection during pregnancy (congenital rubella syndrome). Following universal rubella vaccination of infants in the Netherlands, the incidence of rubella has declined dramatically. However, since September 2004, an outbreak has occurred among unvaccinated individuals, most of whom declined vaccination based on religious beliefs. In the period 1 September 2004-22 March 2005, 166 cases of rubella were reported, including 12 pregnant women. Monitoring for signs that the epidemic has spread to other populations in the Netherlands is important because this might indicate the need for additional interventions. Awareness among health-care workers of the possible occurrence of congenital rubella syndrome should be raised. The clinical manifestations of congenital rubella syndrome are diverse, can be transient or permanent, and may not present until adolescence or adulthood. All cases of laboratory-confirmed rubella infection and congenital rubella syndrome should be reported to municipal health authorities. There is a possibility that this outbreak will spread abroad. The WHO aims to reduce the incidence of congenital rubella syndrome to < 1/100,000 live births. Health-care workers in the Netherlands should be extra alert to detect and notify rubella in a timely manner.

[The measles are here again]. / Er heerst weer mazelen.

Since the vaccination of Dutch children against the measles through the National Immunisation Programme started in 1976, the incidence of measles has greatly decreased. Local epidemics do still occur, however; these are largely confined to minority groups of orthodox Protestants who object to vaccination on religious grounds. A local epidemic of the measles has been developing in the Netherlands since May of this year, predominantly within unvaccinated groups where the highly contagious virus can easily spread. We describe an unvaccinated 10-year-old boy with an uncomplicated case of the measles and an unvaccinated 9-year-old boy who developed encephalitis as a complication of the measles. From the waning of maternal antibodies until the first regular vaccination and where herd immunity is lacking, children are at risk of the measles. For this reason, an extra (age < 12 months) or early (12-14 months) vaccination is being offered during the current epidemic for all children aged 6 to 14 months who live in areas with low (< 90%) vaccination coverage.

Feasibility of a rubella screening and vaccination programme for unvaccinated young women.

The feasibility of a rubella screening and vaccination programme for unvaccinated young women was assessed after the 2004/2005 epidemic in The Netherlands. All 640 young women in two villages with low vaccination coverage were invited for a rubella seroprevalence test. Information on vaccination status was gathered by written questionnaire. Women testing seronegative were offered free rubella vaccination. The feasibility of the programme was evaluated in terms of participation, rubella susceptibility, and acceptance of the vaccination offer by seronegative women. The participation rate was 48% [95% confidence interval (CI) 44-52] with 108 unvaccinated participants. Eleven per cent (95% CI 6-19) of the women were identified as susceptible to rubella, of whom 17% (95% CI 2-48) accepted the vaccination offer. In the end only 0.9% (95% CI 0.1-2.5) of the target population was given protection by the programme. Under the present conditions this programme proved to be an inefficient strategy for rubella protection.