The association between intentional delay of vaccine administration and timely childhood vaccination coverage

Vaccinating for My Family or for My Community? The Effect of Message Framing on Parental Intention to Vaccinate during the COVID Pandemic

BACKGROUND

Social media is one of the major platforms for disseminating essential health messages. The present study examined the effect of message framing (self-interest motive, prosocial motive) on an online platform for parental intention to vaccinate against COVID-19. It also examined how the effect may vary across participants' levels of parental identity centrality/salience and community orientation before the vaccine was officially available.

METHODS

Six hundred and sixty-three Hong Kong Chinese parents were recruited, and a total of 278 valid responses were retained in the analyses. Participants were randomly assigned to one of the three conditions: self-interest motive, prosocial motive, and control. Participants in the self-interest motive condition and the prosocial motive condition read a condition-specific message about the COVID-19 vaccine. Then, they reported their levels of intention to vaccinate against COVID-19, including parent-vaccination, child-vaccination, and medical information-seeking.

RESULTS

A significant group effect on child-vaccination was found. Participants in the self-interest motive condition reported a higher intention to vaccinate their children against COVID-19 compared with the other two conditions. Results of moderation analyses indicated that communal orientation moderated the effect of a self-interest-motive-emphasized message on parental intention to vaccinate against COVID-19. The effect of a self-interest-motive-emphasized message appeared to be stronger on parent-vaccination, child-vaccination, and medical information-seeking among parents who reported lower levels of communal orientation.

CONCLUSION

These findings provided some initial evidence of the effectiveness of message-framing in promoting parents' intention to vaccinate their children on online platforms.

Comparison of Physicians' Attitudes and Practice Regarding Vaccination during Pregnancy in Turkey

This study aimed to investigate the knowledge, attitudes, and behaviors of family physicians (FPs), pediatricians (PPs), and obstetricians and gynecologists (OGs) regarding vaccine administration during pregnancy in Turkey as factors that contribute to decision-making. The survey was distributed among FPs, OGs, and PPs, and participants were asked to rate their knowledge on specific topics using a five-point scale ranging from "Not Effective" to "Effective". The tetanus and diphtheria (Td) vaccine was highly recommended by 94.9% of physicians and considered very effective. Among the physicians surveyed, 80% of PPs and 66.0% of OGs were aware of the disease burden of pertussis. We also found that 74.5% of FPs and 77.2% of PPs believed they needed more information about vaccination during pregnancy. All physicians surveyed agreed or strongly agreed that explaining the disease risks and benefits of vaccination increases the vaccine acceptance rate. The results of this survey study indicate that the knowledge and awareness of physicians need to be improved to increase vaccination rates during pregnancy in Turkey, and it is essential to incorporate influenza and tetanus, diphtheria, and pertussis (TdaP) vaccines into the standard maternal immunization schedule for newborns.

Timeliness of Childhood Vaccinations Following Strengthening of the Second Year of Life (2YL) Immunization Platform and Introduction of Catch-Up Vaccination Policy in Ghana

Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles-rubella vaccine (MR2) and for healthcare workers to assess for and provide children with any missed vaccine doses. In 2016, the Ghana Health Service (GHS) revised its national immunization policies to include guidelines for catch-up vaccinations. This study assessed the change in the timely receipt of vaccinations per Ghana's Expanded Program on Immunizations (EPI) schedule, an important indicator of service quality, following the introduction of the catch-up policy and implementation of a multifaceted intervention package. Vaccination coverage was assessed from household surveys conducted in the Greater Accra, Northern, and Volta regions for 392 and 931 children aged 24-35 months with documented immunization history in 2016 and 2020, respectively. Age at receipt of childhood vaccines was compared to the recommended age, as per the EPI schedule. Cumulative days under-vaccinated during the first 24 months of life for each recommended dose were assessed. Multivariable Cox regression was used to assess the associations between child and caregiver characteristics and time to MR2 vaccination. From 2016 to 2020, the proportion of children receiving all recommended doses on schedule generally improved, the duration of under-vaccination was shortened for most doses, and higher coverage rates were achieved at earlier ages for the MR series. More timely infant doses and caregiver awareness of the 2YL visit were positively associated with MR2 vaccination. Fostering a well-supported cadre of vaccinators, building community demand for 2YL vaccination, sustaining service utilization through strengthened defaulter tracking and caregiver-reminder systems, and creating a favorable policy environment that promotes vaccination over the life course are critical to improving the timeliness of childhood vaccinations.

An ecological analysis of socio-economic determinants associated with paediatric vaccination coverage in the Campania Region: A population-based study, years 2003-2017

Introduction

Vaccines are the most cost-effective and straightforward intervention against severe infectious diseases. However, in Europe and in Italy, paediatric vaccination coverage for certain vaccines remains suboptimal, with considerable regional differences in Italy. Vaccine coverage varies significantly due to socio-economic and organisational factors. Aim of this study was to assess the influence of the Deprivation Index, the density of General Practitioners and General Paediatricians per inhabitants on the coverage of both mandatory and non-mandatory paediatric vaccinations across local health authorities and health districts in the Campania Region for birth cohorts from 2001 to 2015.

Materials and methods

Population-based, ecological time series analysis focusing on the Campania Region, most populous region in the south of Italy. Vaccination coverage data were extracted from the regional immunization database, whilst information on the Deprivation Index and number of primary care doctors and primary care paediatricians per local health district were extracted from public health records. Univariate descriptive statistics were employed to describe study characteristics, as appropriate, whilst and mixed-effect linear regression models were employed to assess the associations between variables of interest and vaccination coverage.

Results

Overall vaccination coverage has generally increased, except for the MMR vaccine, which showed coverage fluctuations. An increase in the Deprivation Index, indicative of less favourable socio-economic conditions, was associated with decreased vaccination coverage in the 24-month age group for some mandatory vaccines (DTaP: Coef -0.97, 95% CI -1.77 | -0.17; Poliomyelitis: Coef -0.98, 95% CI -1.78 | -0.17; Hepatitis B: Coef -0.90, 95% CI -1.71 | -0.10). Moreover, areas with a greater density of General Paediatricians per inhabitants saw increased coverage for Haemophilus influenzae type b in the 6-year age group (Coef 9.78, 95% CI 1.00 | 18.56).

Conclusions

It is necessary to target public health policies to address vaccination inequalities. These efforts should include expanding vaccination campaigns, enhancing catch-up programs, and increase resource allocation in primary care settings to facilitate the role of General Practitioners and Paediatricians in fostering awareness and adherence.

Timeliness of childhood vaccination in England: A population-based cohort study

INTRODUCTION

Vaccine surveillance for children in England focuses on coverage at ages 1, 2, and 5 years. Previous studies exploring vaccine timeliness have used different arbitrary categories to define whether vaccines were received 'late' or 'on time'. This paper aims to provide more detailed and holistic information on timing and patterns of vaccine uptake across the childhood immunisation schedule in England.

METHODS

We included all children born in England between 2006 and 2014 and registered in the Clinical Practice Research Datalink (CPRD) Aurum, a primary care electronic health record. We described vaccine uptake for representative antigens (pertussis, pneumococcus, measles) by age in days and stratified by ethnicity, region and birth cohort. Alluvial diagrams were used to illustrate common journeys through the vaccination schedule, and we applied survival analysis using accelerated failure time models (AFT) to predict age of vaccine receipt based on timing of previous doses.

RESULTS

573,015 children were followed up until their fifth birthday, when they had 90.16 % coverage for two doses of measles, mumps, rubella (MMR) vaccine and 88.78% coverage for four doses of diphtheria, tetanus, pertussis (DTP) vaccine. Overall, the later the age at which a vaccine was due, the more delay in vaccination. Children of Black Ethnicity or from London showed deviating uptake patterns. If a child received their third DTP dose more than a year later than recommended, they would receive the next dose 2.7 times later than a child who was vaccinated on time. A smaller delay was found for children who did not receive first MMR dose on time.

DISCUSSION

We showed that the risk of vaccination delay increased with the age of the child and significant delay of previous doses. Primary care data can help to promptly identify children at higher risk of delayed vaccination.

Estimating Vaccine Hesitancy in Colorado by Using Immunization Information System Data

OBJECTIVES

Vaccine hesitancy is a complex issue that threatens global health. We used data from the Colorado Immunization Information System (CIIS) to quantify vaccine hesitancy.

METHODS

We examined immunization records from CIIS for patients age 2 up to 9 months to estimate vaccine hesitancy by tabulating the number of doses received per visit and comparing it with the number of expected doses based on recommendations of the Advisory Committee on Immunization Practices. We calculated the percentage of patients in each vaccine hesitancy group who were up to date on the 7-antigen series by age 35 months. We examined the distribution of vaccine-hesitant populations among vaccination providers who report to CIIS to estimate the difference in vaccine-hesitant patient populations among vaccination providers in Colorado.

RESULTS

Of 201 450 patients, 5147 (2.6%) consistently limited the number of shots received at each visit as compared with recommendations from the Advisory Committee on Immunization Practices; 166 927 (82.9%) patients did not limit the number of shots received; 5693 (2.8%) limited the number of shots received at >1 visit but not all visits; and 23 683 (11.8%) limited the number of shots received at only 1 visit. We found differences in vaccine hesitancy distributions among certain Colorado vaccination providers.

CONCLUSIONS

Immunization information system data, although sometimes incomplete, offer an opportunity to investigate state-level vaccine hesitancy. Areas of future research include performing similar analyses over time and determining geographic and socioeconomic factors that contribute to vaccine hesitancy.

Immunisation status of children receiving care and support in Wales: a national data linkage study

Background

In the UK, a robust childhood immunisation programme ensures children are offered protection against serious infections; identifying inequalities in vaccination coverage is essential. This is one of the first data linkage studies to examine coverage of primary, as well as pre-school booster and second dose of MMR vaccines, in children receiving support from social care services across Wales.

Methods

By accessing records held within the Secure Anonymised Information Linkage (SAIL) Databank, vaccination status of children receiving social care and support between April 2016 and March 2021 (n = 24,540) was ascertained. This was achieved through linkage of the Children Receiving Care and Support (CRCS) Census and National Community Child Health Database which holds vaccination records for all children in Wales registered for NHS care. This sample was split into three groups - those children who had never been recorded on the Child Protection Register (CPR) or as 'Looked After' but in CRCS (n = 12,480), children ever on the CPR (n = 6,225) and those ever recorded as 'Looked After' but who were never on the CPR (n = 5,840). The comparison group of children and young people (CYP) never receiving welfare support consisted of 624,905 children.

Results

Children receiving care or support were more likely to be up-to-date with all six vaccines (no recorded vaccines: 0.6-6.3%) compared to children in the comparison group (no recorded vaccines: 3-10.3%). However, of those who were vaccinated, they were less likely to be vaccinated in a timely manner; both early (5.2% vs. 22.2%; margin of error [ME] = 0.52, 95% CI [confidence interval] = -0.18 - -0.17, p < 0.001) and delayed vaccinations were more common (62.7% vs. 71.3%; ME = 0.58, 95% CI = 0.08-0.09, p < 0.001). Validation of the CRCS immunisation flag showed moderate levels of accuracy. Around 70% of immunisation flags were correct across all three groups.

Discussion

Findings suggest a positive association between receiving services under a care and support plan and being up-to-date with immunisations; children receiving support under a care and support plan were more likely to have experienced early or late vaccinations, demonstrating that there is still more inter-disciplinary co-ordination and planning needed to improve these outcomes. Thus, identifying inequalities in vaccination coverage is essential to target interventions and to prioritise geographic areas for catch-up.

Interventions for COVID-19 Vaccine Hesitancy: A Systematic Review and Narrative Synthesis

Vaccines effectively protect against COVID-19, but vaccine hesitancy and refusal hinder vaccination rates. This systematic review aimed to (1) review and describe current interventions for addressing COVID-19 vaccine hesitancy/refusal and (2) assess whether these interventions are effective for increasing vaccine uptake. The protocol was registered prospectively on PROSPERO and comprehensive search included Medline, Embase, CINAHL, PsycInfo, and Web of Science databases. Only studies that evaluated the effectiveness of non-financial interventions to address COVID-19 vaccine hesitancy were included, while those focusing intentions or financial incentive were excluded. Risk of bias for all included studies was evaluated using Cochrane risk of bias tools. In total, six articles were included in the review (total participants n = 200,720). A narrative synthesis was performed due to the absence of common quantitative metrics. Except for one randomized controlled trial, all studies reported that interventions were effective, increasing COVID-19 vaccination rates. However, non-randomized studies were subject to confounding biases. Evidence on the effectiveness of COVID-19 vaccine hesitancy interventions remains limited and further evidence is needed for the development of clear guidance on effective interventions to increase vaccine uptake.

Why Parents Say No to Having Their Children Vaccinated against Measles: A Systematic Review of the Social Determinants of Parental Perceptions on MMR Vaccine Hesitancy

Ongoing outbreaks of measles threaten its elimination status in the United States. Its resurgence points to lower parental vaccine confidence and local pockets of unvaccinated and undervaccinated individuals. The geographic clustering of hesitancy to MMR indicates the presence of social drivers that shape parental perceptions and decisions on immunization. Through a qualitative systematic review of published literature (n = 115 articles; 7 databases), we determined major themes regarding parental reasons for MMR vaccine hesitancy, social context of MMR vaccine hesitancy, and trustworthy vaccine information sources. Fear of autism was the most cited reason for MMR hesitancy. The social drivers of vaccine hesitancy included primary care/healthcare, education, economy, and government/policy factors. Social factors, such as income and education, exerted a bidirectional influence, which facilitated or hindered vaccine compliance depending on how the social determinant was experienced. Fear of autism was the most cited reason for MMR hesitancy. Vaccine hesitancy to MMR and other childhood vaccines clustered in middle- to high-income areas among mothers with a college-level education or higher who preferred internet/social media narratives over physician-based vaccine information. They had low parental trust, low perceived disease susceptibility, and were skeptical of vaccine safety and benefits. Combating MMR vaccine misinformation and hesitancy requires intersectoral and multifaceted approaches at various socioecological levels to address the social drivers of vaccine behavior.

Factors Associated with Vaccination Uptake among Young Children: A Follow-Up Study of 1799 Toddlers

Childhood vaccination is crucial to protect young children from harmful infectious diseases. This study aimed to investigate the recent childhood immunization rate of recommended and additional vaccinations and identify the factors affecting the vaccination uptake of young children in Hong Kong. The self-administrated questionnaires were distributed to parents of toddlers aged 2 to 5. They were asked to provide information on (1) socioeconomic demographic factors; (2) experiences during pregnancy; and (3) the medical history of the toddler. A total of 1799 responses were collected. Children were more likely to be fully vaccinated when they were at a younger age (aOR = 0.61, 95% CI: 0.48–0.78, p < 0.001), the first child in the family (aOR second-born = 0.62, 95% CI: 0.48–0.81, p < 0.001; aOR third-born = 0.33, 95% CI: 0.19–0.55, p < 0.001), had a higher household income (aOR HKD 15,000–HKD 29,999 = 1.80, 95% CI: 1.27–2.55, p = 0.001; aOR ≥ HKD 30,000 = 3.42, 95% CI: 2.39–4.90, p < 0.001; compared with <HKD 15,000), or with mothers in older age groups (aOR 35–39 years old = 2.45, 95% CI = 1.22–4.93, p = 0.012; aOR ≥ 40 = 2.90, 95% CI = 1.24–6.77, p = 0.014; compared with ≤ age 24). The uptake of any additional vaccination was 71%. Children who were older (aOR = 1.32, 95% CI: 1.02–1.70, p = 0.036), the first child in the family (aOR second-born = 0.74, 95% CI: 0.56–0.99, p = 0.043; aOR third-born = 0.55, 95% CI: 0.32–0.96, p = 0.034), with higher household income (aOR ≥ HKD 30,000 = 1.61, 95% CI: 1.10–2.37, p = 0.016), were exposed to second-hand smoke from the father (aOR: 1.49, 95% CI: 1.08–2.07, p = 0.016), experienced hospitalization (twice or more—aOR: 1.44, 95% CI: 1.04–1.99, p = 0.027), or were fully vaccinated (aOR: 2.76, 95% CI: 2.12–3.60, p < 0.001) were associated with a higher chance of taking an additional vaccine. To encourage the vaccination rate, more attention should be given to families with more children, low-income families, and younger mothers.

Vaccine hesitancy and its determinants among refugee parents resettled in Aotearoa New Zealand

Vaccine hesitancy is an important factor underpinning suboptimal vaccine uptake and evidence on marginalized subgroups, such as refugees, is limited. This cross-sectional survey was conducted in 2020/21 with former refugee parents who resettled in Aotearoa New Zealand (NZ). The Parent Attitudes about Childhood Vaccines (PACV) was offered in Somali, Oromo, Arabic, and English languages, and the reliability of the four versions were evaluated. The prevalence of parental vaccine hesitancy was explored and the association between vaccine hesitancy and sociodemographic factors was examined using logistic regression. One hundred and seventy-eight responses were included in the analysis. The Cronbach's alpha scores for Somali, Oromo, Arabic, and English PACV were 0.89, 0.64, 0.53, and 0.77, respectively. The rate of parental vaccine hesitancy was 16.3%, 95% CI (10.7, 21.3). Most caregivers were concerned about vaccine side effects (47%), safety (43%), and efficacy (40%). Less than a quarter (21%) of parents had delayed their child receiving a vaccine and 12% had refused to vaccinate their child for reasons other than medical exemptions. After adjusting for covariate/s, parents' primary source of information and education status were significantly associated with vaccine hesitancy. Media as a primary source of vaccine information and low education status were associated with higher vaccine hesitancy. Vaccine hesitancy is relatively low among former refugees and is influenced by modifiable factors, including educational level and primary source of vaccine information. Vaccine information tailored to former refugee parents' concerns are required to reduce vaccine hesitancy and improve vaccine uptake.

Linking cohort data and Welsh routine health records to investigate children at risk of delayed primary vaccination

BACKGROUND

Delayed primary vaccination is one of the strongest predictors of subsequent incomplete immunisation. Identifying children at risk of such delay may enable targeting of interventions, thus decreasing vaccine-preventable illness.

OBJECTIVES

To explore socio-demographic factors associated with delayed receipt of the Diphtheria, Tetanus and Pertussis (DTP) vaccine.

METHODS

We included 1,782 children, born between 2000 and 2001, participating in the Millennium Cohort Study (MCS) and resident in Wales, whose parents gave consent for linkage to National Community Child Health Database records at the age seven years contact. We examined child, maternal, family and area characteristics associated with delayed receipt of the first dose of the DTP vaccine.

RESULTS

98.6% received the first dose of DTP. The majority, 79.6% (n = 1,429) received it on time (between 8 and 12 weeks of age), 14.2% (n = 251) received it early (prior to 8 weeks of age) and 4.8% (n = 79) were delayed (after 12 weeks of age); 1.4% (n = 23) never received it. Delayed primary vaccination was more likely among children with older natural siblings (risk ratio 3.82, 95% confidence interval (1.97, 7.38)), children admitted to special/intensive care (3.15, (1.65, 5.99)), those whose birth weight was > 4Kg (2.02, (1.09, 3.73)) and boys (1.53, (1.01, 2.31)). There was a reduced risk of delayed vaccination with increasing maternal age (0.73, (0.53, 1.00) per 5 year increase) and for babies born to graduate mothers (0.27, (0.08, 0.90)).

CONCLUSIONS

Although the majority of infants were vaccinated in a timely manner, identification of infants at increased risk of early or delayed vaccination will enable targeting of interventions to facilitate timely immunisation. This is to our knowledge the first study exploring individual level socio-demographic factors associated with delayed primary vaccination in the UK and demonstrates the benefits of linking cohort data to routinely-collected child health data.

Hesitancy towards Childhood Vaccinations among Parents of Children with Underlying Chronic Medical Conditions in Italy

Background: This study was designed to evaluate vaccination hesitancy and behaviors among parents of children with chronic conditions. Methods: This cross-sectional study was conducted from June to December 2021 in three public hospitals in southern Italy. Data were collected using a face-to-face interview of parents of children up to 17 years of age with at least one chronic condition. Results: Of the 532 parents approached, 444 agreed to participate, with a response rate of 83.4%. Almost half of parents (43%) knew that children with chronic diseases are at greater risk of complications from VPDs, and 21.6% knew all the vaccinations available in Italy. Additionally, 55.9% felt that vaccine-preventable diseases (VPDs) are very dangerous for their children, and 28.7% were very worried about the side effects of vaccines. The result of the Parent Attitudes about Childhood Vaccine (PACV) score indicated that 23.2% of parents were hesitant about vaccinations. Parental vaccine hesitancy was significantly more common among parents who had female children, among those who did not know the recommended vaccinations, among those who had a higher concern of potential side effects of the vaccines, among those who believed that the administration of the vaccinations was not useful, and among who received information on recommended vaccination from the internet, social and mass media. Conclusions: Important efforts by policy makers and healthcare providers must be implemented to counter vaccine hesitancy among parents.

Evaluating vaccination coverage and timeliness in American Indian/Alaska Native and non-Hispanic White children using state immunization information system data, 2015-2017

Comprehensive estimates of vaccination coverage and timeliness of vaccine receipt among American Indian/Alaska Native (AI/AN) children in the United States are lacking. This study’s objectives were to quantify vaccination coverage and timeliness, as well as the proportion of children with specific undervaccination patterns, among AI/AN and non-Hispanic White (NHW) children ages 0–24 months in Montana, a large and primarily rural U.S. state. Data from Montana’s immunization information system (IIS) for children born 2015–2017 were used to calculate days undervaccinated for all doses of seven recommended vaccine series. After stratifying by race/ethnicity, up-to-date coverage at key milestone ages and the proportion of children demonstrating specific patterns of undervaccination were reported. Among n = 3,630 AI/AN children, only 23.1% received all recommended vaccine doses on-time (i.e., zero days undervaccinated), compared to 40.4% of n = 18,022 NHW children (chi-square p < 0.001). A greater proportion of AI/AN children were delayed at each milestone age, resulting in lower overall combined 7-vaccine series completion, by age 24 months (AI/AN: 56.6%, NHW: 64.3%, chi-square p < 0.001). As compared with NHW children, a higher proportion of AI/AN children had undervaccination patterns suggestive of structural barriers to accessing immunization services and delayed starts to vaccination. More than three out of four AI/AN children experienced delays in vaccination or were missing doses needed to complete recommended vaccine series. Interventions to ensure on-time initiation of vaccine series at age 2 months, as well initiatives to encourage completion of multi-dose vaccine series, are needed to reduce immunization disparities and increase vaccination coverage among AI/AN children in Montana.

Factors related to parents’ adherence to childhood immunization

Background

Immunizations protect children from deadly infectious diseases. Yet, there is still insufficient understanding of the factors associated with parents’ non-adherence to immunizations in contexts outside of Western countries. The aim of this study is twofold: (a) to investigate non-adherence to immunizations for children aged 6 months to 6 years in Saudi Arabia based on the number of immunizations missing or delayed by more than one month; and (b) to examine the underlying factors that predict the extent of non-adherence based on the Health Belief Model framework.

Methods

A cross-sectional study was carried out in 22 randomly selected primary health care centers. Structured interviews were also conducted to collect data using the modified Health Belief Model questionnaire. Multiple regression analysis was used to assess the predictors of the extent of non-adherence.

Results

Based on data from 220 participants, 51.8% of parents did not adhere with childhood immunizations. There was no significant relationship between parents’ sociodemographic characteristics and the extent of their hesitancy about children’s immunizations. The linear combination of perception of infectious disease severity, perception of their children’s susceptibility, perception of immunization benefits, perception of fewer barriers to obtaining immunizations, cues to action related to immunizations, and self-efficacy predicted the extent of non-adherence to immunizations (F (11.220) = 2.595, p < 0.001) and explained 12% of its variance. Yet, only perceived children’s susceptibility, perceived barriers, and self-efficacy independently predicted parents’ non-adherence.

Conclusion

Saudi Arabia’s high proportion of non-adherence to childhood immunizations should be addressed. For instance, a health education program could be developed to increase parents’ awareness that their children are susceptible to health risks. Paying a special attention to existing barriers in accessing and receiving the immunizations is crucial. In addition, building parents’ self-efficacy, which is confident in making healthy decisions, such as keeping their children’s immunizations up to date, is important.

Evaluating public acceptability of a potential Lyme disease vaccine using a population-based, cross-sectional survey in high incidence areas of the United States

BACKGROUND

Lyme disease incidence is increasing, despite current prevention options. New Lyme disease vaccine candidates are in development, however, investigation of the acceptability of a Lyme disease vaccine among potential consumers is needed prior to any vaccine coming to market. We conducted a population-based, cross-sectional study to estimate willingness to receive a potential Lyme disease vaccine and factors associated with willingness.

METHODS

The web-based survey was administered to a random sample of Connecticut, Maryland, Minnesota, and New York residents June-July 2018. Survey-weighted descriptive statistics were conducted to estimate the proportion willing to receive a potential Lyme disease vaccine. Multivariable multinomial logistic regression models were used to quantify the association of sociodemographic characteristics and Lyme disease vaccine attitudes with willingness to be vaccinated.

RESULTS

Surveys were completed by 3313 respondents (6% response rate). We estimated that 64% of residents were willing to receive a Lyme disease vaccine, while 30% were uncertain and 7% were unwilling. Compared to those who were willing, those who were uncertain were more likely to be parents, adults 45-65 years old, non-White, have less than a bachelor's degree, or have safety concerns about a potential Lyme disease vaccine. Those who were unwilling were also more likely to be non-White, have less than a bachelor's degree, or have safety concerns about a potential Lyme disease vaccine. In addition, the unwilling had low confidence in vaccines in general, had low perceived risk of contracting Lyme disease, and said they would not be influenced by a positive recommendation from a healthcare provider.

DISCUSSION

Overall, willingness to receive a Lyme disease vaccine was high. Effective communication by clinicians regarding safety and other vaccine parameters to those groups who are uncertain will be critical for increasing vaccine uptake and reducing Lyme disease incidence.

Adherence to the paediatric immunisation schedule in England

Both adequate coverage and adherence to paediatric immunisation schedules are required for optimal protection against vaccine preventable diseases. We studied the timeliness of routine paediatric vaccinations according to the NHS’s immunisation schedule and potential factors of schedule adherence. Immunisation data was obtained from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We collected vaccine types, doses, and dates for all routine paediatric vaccines between 2008 and 2018: DTaP/IPV/Hib/HepB, DTaP/IPV/Hib, DTaP/IPV, dTaP/IPV, Td/IPV, MMR, PCV, MenB, MenC, MenACWY, Hib/MenC, RV, HPV. Adherence to the immunisation schedule was calculated for each vaccine and dose. Differences in adherence between genders, NHS regions, and IMD quintiles were analysed. Our study included 6′257′828 vaccinations in 1′005′827 children. Seventy-five percent of first doses were administered within one (for vaccines scheduled in the first year of life) or two months (for vaccines scheduled later in life) following the recommended age, 19% too late and 6% too early. About half of the subsequent doses were given timely. The time between first and second doses was too short for 36% of vaccinations while 13% of second doses were administered too long after the first dose. Third doses were administered timely for 45%, too short for 37%, and too long for 18% of vaccinations. Differences in immunisation schedule adherence between girls and boys were negligible, except for HPV, and differences between the four main NHS regions were small. Overall, immunisation schedule adherence improved slightly with decreasing deprivation according to the Index of Multiple Deprivation. Efforts are required to improve the timeliness of paediatric vaccinations and to assure adequate protection against vaccine preventable diseases. We propose developing a compound measure combining coverage and adherence to provide a better indication of the protection against vaccine preventable diseases in a community.

Knowledge of mothers regarding children's vaccinations in Cyprus: A cross-sectional study

INTRODUCTION

Vaccine hesitancy is identified as one of the top threats to global health. A significant drop of childhood vaccine coverage is reported worldwide. One of the key reasons that influenced mothers' choice to postpone, or avoid children's vaccination, is knowledge. This study aimed to assess the level of Cypriot mothers' knowledge on certain aspects of vaccination of their children, examine the association between vaccination knowledge and selected socio-demographic factors, and lastly assess the association of mothers' knowledge about vaccination with vaccination coverage and delay, compliance to the recommended schedules, vaccination during pregnancy and mother-pediatrician relationship.

METHODS

An online-based cross-sectional study conducted to collect information about socio-demographic characteristics, child's characteristics, vaccination, and vaccine knowledge, using a self-administered questionnaire. The survey was conducted between April 2020 and June 2020 and the study population included mothers over 18 years old with at least one child (<18 years old) living in Cyprus.

RESULTS

A total of 703 Cypriot mothers participated in the study. Most of the participants stated that they vaccined their children (97%) and the most popular source of information about vaccination was their pediatrician (90%). More than half of the participants (57%) have delayed their child/children vaccination with their pediatrician's suggestion being the main reason. 36% of mothers had low knowledge while the overall correct rate was 13.6% and the median (IQR) knowledge score was 11 (9-12). Having a medium knowledge about vaccination was associated with having a medium or high income, whilst high knowledge compared to low knowledge was associated with completed a higher education and having a high income. Our analysis showed that the correct knowledge by mothers with regards to vaccination increases the probability of vaccinating their children, following the local recommendations for vaccine dosages, and acquiring and trusting vaccination-related information from their children's pediatrician.

CONCLUSION

Our findings show that the majority of mothers in Cyprus had positives perceptions regarding childhood vaccination, as reflected with the high vaccination rate, however, some aspects of mothers' knowledge of vaccination need to be improved. Public health strategies to promote vaccination, education programs as well as improved communication tools between pediatricians and mothers need to be considered to achieve favorable vaccination attitudes and practices for all mothers in Cyprus.

Enablers and barriers to COVID-19 vaccine uptake: An international study of perceptions and intentions

The development of COVID-19 vaccines is occurring at unprecedented speeds, but require high coverage rates to be successful. This research examines individuals’ psychological beliefs that may act as enablers and barriers to vaccination intentions. Using the health beliefs model as a guide to our conceptual framework, we explore factors influencing vaccine hesitancy and health beliefs regarding risks and severity of the disease, along with individual variables such as income, age, religion, altruism, and collectivism. A questionnaire using newly created measures for various antecedents provided 4303 usable responses from Australia, Canada, England, New Zealand, and the United States. A factor analytic and structural equation model indicates that trust in vaccine approval, the perceived effectiveness of the vaccine for protecting others, and conspiracy beliefs are the most significant drivers of intentions to vaccinate. Older people, those seeking employment, and those who have received a recent influenza vaccine are more likely to be vaccinated against COVID-19. The findings have implications for improving communication strategies targeting individuals about the merits of vaccination, particularly focusing on younger individuals and expanded message framing to include altruistic considerations, and to improve government transparency regarding the effectiveness and side effects of vaccines.

The impact of paid family leave on the timely vaccination of infants

Time constraints parents face can affect whether infant children are vaccinated on time. Using the National Immunization Survey, we employ a synthetic control difference-in-difference estimation technique to establish a causal relationship arising from California's implementation of Paid Parental Leave Program as a natural experiment. We find California Paid Family Leave reduced late vaccinations by up to 5 percentage points or approximately 10% for children born to parents in California after the policy was implemented. Further, the policy had a stronger impact on families below the poverty line. Thus access to paid family leave can improve on-time immunization of infants.

Hepatitis B birth dose vaccination patterns in the military health System, 2014-2018

BACKGROUND

Since 2005, the universal hepatitis B (HepB) birth dose has been recommended for all medically stable infants weighing ≥2,000 g at birth. The timing of the birth dose provides a critical safeguard and prevents infection among infants born to HBsAg-positive mothers not identified prenatally. We assess infant HepB vaccination in the U.S. Department of Defense's Military Health System (MHS) to identify trends in vaccination coverage and sociodemographic factors associated with non-receipt of the birth dose, receiving the first HepB vaccine >3 days of life, and not receiving any HepB vaccine in the first 18 months of life utilizing parental refusal codes. To our knowledge, this is one of the first studies assessing trends in parental refusal of the HepB birth dose utilizing administrative claims parental refusal codes.

METHODS

We conducted a retrospective cohort analysis of MHS live births from January 1, 2014 through December 31, 2018 utilizing administrative claims data. Data were included from 44 hospitals in 24 unique states, territories, or countries. We analyzed diagnosis codes for vaccine refusal and vaccination and current procedural terminology (CPT) codes to identify vaccination patterns. Generalized linear mixed effects models with a logit link were used to assess factors associated with vaccination patterns.

RESULTS

HepB birth dose vaccination coverage increased from 79.6% in 2014 to 88.1% in 2018 (p < .0001). Refusal rates also increased from 3.7% in 2014 to 4.5% in 2018 (p < .0001). The percentage of patients with missing diagnosis codes for vaccine refusal or vaccination decreased from 16.7% in 2014 to 7.4% in 2018. Factors associated with non-receipt of the birth dose included earlier year of birth, white maternal race, higher maternal age, higher birth order, and longer infant length of stay in hospital.

CONCLUSION

Vaccination coverage for HepB birth dose is high in the MHS and increased over time; concurrently, refusal rates also increased over time. Utilizing administrative claims data has the benefit of differentiating reasons for non-receipt of the birth dose over time.

A validated modification of the vaccine hesitancy scale for childhood, influenza and HPV vaccines

INTRODUCTION

Vaccine hesitancy contributes to outbreaks of preventable disease worldwide. The Vaccine Hesitancy Scale (VHS), developed by the international WHO SAGE Working Group, has been validated previously for measuring hesitancy towards childhood vaccines; some psychometric properties were suboptimal.

METHODS

We collected data using large, nationally-representative samples of parents in the U.S. We adapted the VHS items, and additional hesitancy items, to assess hesitancy towards influenza and HPV vaccines in addition to routine childhood vaccines. We then used exploratory and confirmatory factor analysis to identify latent constructs and create modified scales for childhood (VHS-child), influenza (VHS-flu) and HPV (VHS-HPV) vaccines with improved psychometric properties. Finally, we compared hesitancy scores on the VHS-child, VHS-flu, and VHS-HPV, to self-reported receipt of each vaccine category, and compared subscale scores to assess whether drivers of hesitancy differed by vaccine category.

RESULTS

2052 parents of children <18 years old completed the VHS-child and VHS-flu while 2020 parents of adolescents completed the VHS-HPV. A two-factor structure of 'risks' and a 'lack of confidence' was found for each vaccine category. Slight modifications to the VHS improved psychometric properties. Hesitancy was strongly associated with vaccine receipt: e.g., 76% of parents not hesitant towards influenza vaccine had vaccinated their child the past season, versus 9% of hesitant parents (p < 0.0001). Subscale scores also differed significantly between vaccines: lack of confidence was greater towards influenza (Median (IQR): 2.0 (1.2, 3.3)) and HPV (2.0 (1.3, 3.0)) vaccines than childhood (1.2 (1.0, 1.8), p < 0.0001 for both) vaccines; perceived risks of HPV vaccines (2.7 (1.7, 3.7)) were greater than for childhood vaccines (2.0 (1.3, 3.0), p < 0.0001).

CONCLUSIONS

Our modified VHS scales perform well psychometrically and allow for consistent measurement of the extent and reasons for hesitancy between vaccine categories. We suggest that future work use these scales to examine hesitancy towards other vaccines and to monitor hesitancy over time.

Access to Vaccination Information and Confidence/Hesitancy Towards Childhood Vaccination: A Cross-Sectional Survey in China

Access to vaccination information could influence public attitudes towards vaccination. This study investigated the number and types of vaccination-related information sources, and estimated their associations with vaccine confidence and hesitancy in China. In January 2019, we conducted a cross-sectional survey in China, and 2122 caregivers with children <6 years completed self-administered questionnaires. Logistic regressions were used to assess associations between caregivers’ primary information sources and vaccine confidence/hesitancy. A majority (72%) of caregivers had multiple sources of vaccination-related information. The proportions of caregivers reporting professional sources, media, and peers as primary information sources were 81%, 63%, and 26%. Internal migrants were less likely to get information from professional sources; more educated and wealthier caregivers reported more information sources and were more likely to get information from media and peers. Caregivers who reported professional information sources had significantly higher odds of being confident about the safety of vaccines and lower odds of being hesitant toward vaccination than those who did not. Caregivers who reported the media as a primary information source had significantly higher odds of being hesitant toward vaccination than those who did not. To address vaccine hesitancy, it is essential to promote universal access to professional vaccination-related information sources, and to use the media to disseminate evidence-based information and clarify misinformation. Health communication should target internal migrants, and more educated and wealthier caregivers.

Prevalence and predictors of vaccine hesitancy in an urbanized agglomeration of New Delhi, India

Background

The immunization program has been an important part of Indian public health policy for three decades; yet only 62% of children are being fully immunized. Vaccine hesitancy is a major contributor to the immunization gap that needs to be addressed.

Methods

A cross-sectional descriptive study of prevalence and predictors of vaccine hesitancy was conducted in 350 households having at least one child in the age group of 13–24 months. Statistical analysis was done using chi-square test and logistic regression.

Results

The prevalence of vaccine hesitancy was 28.9%. Fear of needles, concern about pain during vaccination, lack of family support, and apprehension regarding side effects were ascertained as reasons for vaccine hesitancy. The type of family, time taken to reach the health facility and antenatal care received by the mother were significant predictors of vaccine hesitancy.

Conclusion

The prevalence of vaccine hesitancy was found to be high. In 2019, the World Health Organization earmarked vaccine hesitancy as one of the major roadblocks to better global health. A better understanding of the subject can help public health agencies enhance vaccination coverage, not just in children but also as a tool to protect entire populations in this age of re-emerging epidemics.

Health Care Worker Preferences and Perspectives on Doses per Container for 2 Lyophilized Vaccines in Senegal, Vietnam, and Zambia

When providing immunization services, health care workers balance the mandate of achieving high coverage with limiting vaccine wastage. Workers in 3 countries said that containers with fewer vaccine doses for measles and BCG would enable them to immunize all children who present, while reducing concerns about wasting vaccine.

Introduction:

Limited information exists on health care workers’ (HCWs) perceptions about use of multidose vaccine vials and their preferences about doses per container (DPC). We present findings from qualitative studies conducted in Senegal, Vietnam, and Zambia to explore HCWs’ behavior regarding opening vials and their perceptions and preferences for the number of doses in vials of BCG and measles-containing vaccine (MCV). Zambia and Senegal currently offer MCV in 10-dose vials and BCG in 20-dose vials; 10-dose vials are used for both vaccines in Vietnam. Unused doses in vials of these reconstituted vaccines must be discarded within 6 hours.

Methods:

Key informant interviews (KIIs) were conducted with frontline HCWs in Senegal, Vietnam, and Zambia. In Senegal and Vietnam, the KIIs were conducted as part of broader formative research; in Zambia, KIIs were conducted in control districts using 10-dose MCV vials only and in intervention districts that switched from 10- to 5-dose vials during the study. During analysis, themes common to all 3 countries were synthesized. Critical themes relevant to country contexts were also examined.

Results:

HCWs in all 3 countries preferred containers with fewer doses for BCG and MCV to reduce wastage and increase the likelihood of vaccinating every eligible child. HCWs in Senegal and HCWs using 10-dose vials in Zambia reported sending unvaccinated children away because not enough children were present to warrant opening a new vial. In Vietnam, where sessions are typically held monthly, and in Zambia when the 5-dose vials were used, almost all HCWs reported opening a vial of MCV for even 1 child.

Discussion:

HCWs prefer vials with fewer DPC. Their concerns about balancing coverage and wastage influence their decisions to vaccinate every eligible child; and their perspectives are crucial to ensuring that all target populations are reached with vaccines in a timely manner.

Parental vaccine attitudes, beliefs, and practices: initial evidence in California after a vaccine policy change

Senate Bill 277 (SB277) eliminated nonmedical exemptions for school-entry vaccines in California, but the impact of parental vaccine knowledge, attitudes, and beliefs on vaccine decision-making has not been extensively examined within the post-SB277 context. This study generates preliminary understanding and discussion of the vaccination knowledge, attitudes, and beliefs among a pilot population of parents of kindergarten students in California after the implementation of SB277. School officials administered a cross-sectional survey to parents of kindergarten children in California from April to July 2019. Parents reported their perceptions of diseases and vaccines, key immunization beliefs, and confidence in different sources of vaccine information. Most parents (92%) had fully vaccinated their children post-SB277 and generally perceived vaccines to be safe and effective, but about 44% reported they were hesitant about childhood vaccines. The majority of parents (87%) rated vaccine information from their doctor as highly credible. This pilot group of kindergarten parents was generally supportive of vaccination and had fully vaccinated their children, but most parents still harbored concerns and misconceptions about vaccines and about public health authorities. This indicates a disconnect between parental vaccine compliance and confidence, and suggests that educational interventions could impact parental vaccine behavior and decision-making.

The role of epidemiology in informing United States childhood immunization policy and practice

One of the ten greatest public health achievements is childhood vaccination because of its impact on controlling and eliminating vaccine-preventable diseases (VPDs). Evidence-based immunization policies and practices are responsible for this success and are supported by epidemiology that has generated scientific evidence for informing policy and practice. The purpose of this report is to highlight the role of epidemiology in the development of immunization policy and successful intervention in public health practice that has resulted in a measurable public health impact: the control and elimination of VPDs in the United States. Examples in which epidemiology informed immunization policy were collected from a literature review and consultation with experts who have been working in this field for the past 30 years. Epidemiologic examples (e.g., thimerosal-containing vaccines and the alleged association between the measles, mumps, and rubella (MMR) vaccine and autism) are presented to describe challenges that epidemiologists have addressed. Finally, we describe ongoing challenges to the nation's ability to sustain high vaccination coverage, particularly with concerns about vaccine safety and effectiveness, increasing use of religious and philosophical belief exemptions to vaccination, and vaccine hesitancy. Learning from past and current experiences may help epidemiologists anticipate and address current and future challenges to respond to emerging infectious diseases, such as COVID-19, with new vaccines and enhance the public health impact of immunization programs for years to come.

Resources for assessing parents' vaccine hesitancy: a systematic review of the literature

The concept of Vaccine Hesitancy has begun to appear in the scientific landscape, referring to the reluctance of a growing proportion of people to accept the vaccination offer. A variety of factors were identified as being associated with vaccine hesitancy but there was no universal algorithm and currently there aren’t any established metrics to assess either the presence or impact of vaccine hesitancy. The aim of this study was to systematically review the published questionnaires evaluating parental vaccine hesitancy, to highlight the differences among these surveys and offer a general overview on this matter. This study offers a deeper perspective on the available questionnaires, helping future researches to identify the most suitable one according to their own aim and study setting.

Timeliness of routine vaccination among children and determinants associated with age-appropriate vaccination in Mongolia

INTRODUCTION

Routine vaccination at the recommended age is crucial to minimize the risk of acquiring vaccine preventable diseases. This study aimed to assess the proportion of children receiving routine immunization at the recommended age and determinants of timely (age-appropriate) vaccination in Mongolia.

MATERIAL AND METHOD

A total of 879 eligible children aged 12-23 months were included in this study. We investigated age-appropriate administration of Bacillus Calmette-Guerin vaccine (BCG); hepatitis B vaccine (Hep B); oral polio vaccine (OPV); pentavalent vaccine; and measles, mumps, and rubella vaccine (MMR) using Kaplan-Meier method. Multilevel logistic regression with random intercept at cluster level was used to assess the determinants of age-appropriate vaccination.

RESULTS

Overall, the crude vaccination coverage for routine vaccinations were above 90% for all vaccines except MMR1 which was 86.0% (95% CI, 83.6-88.2). While the first dose of almost all the vaccines given at birth; BCG, Hep B, and OPV0, were administered in a timely manner, a substantial proportion of second and third doses of these vaccines were not given in a timely manner with age-appropriate vaccination coverage ranging from 35.9% (32.8-39.1%) for MMR1 to 67.7% (64.5-70.7%) for OPV1 respectively. Factors associated with age-appropriate administration of the investigated vaccines included socio-economic status of household, religion of household heads, area of residence, owning mobile phone, and season of childbirth. For instance, children belonging to households from richer wealth quintile had higher possibilities of getting age-appropriate OPV1-OPV3, PE1-PE3 and MMR1 vaccines compared to those from the poorest household wealth quintile.

CONCLUSION

Our findings suggest that the commonly used indicator 'crude vaccination coverage' could be supplemented by 'age-appropriate vaccination' to help to identify gaps in timely vaccinations and stimulate interventions in Mongolia. Factors such as household wealth quintile, place of residence and religion associated with timely vaccination in our study could be considered to promote effective intervention aiming to improve adequate vaccination coverage.

Recent advances in addressing vaccine hesitancy

PURPOSE OF REVIEW

To offer healthcare providers current, evidence-based approaches for addressing vaccine hesitancy to increase vaccine coverage and reduce the frequency of vaccine-preventable disease outbreaks.

RECENT FINDINGS

Vaccine hesitancy is a growing problem with profound societal, economic, and medical consequences. Understanding the complexity of vaccine hesitancy can inform approaches to increasing vaccine uptake on both the individual and population levels. Notably, pediatricians play a critical role in increasing vaccine uptake due to their relationships with families. This doctor-patient relationship establishes trust and allows evidence-based intervention strategies to be effective in the office. Understanding potential solutions outside the office, such as media campaigns and policy changes, also provide insight into vaccine hesitancy and potential directions for future research. While pediatricians' attempts in the clinic to increase coverage remain crucial, vaccine hesitancy remains a formidable public health problem that requires attention on both the micro and macro levels to be addressed successfully.

SUMMARY

Providers have an opportunity to increase both confidence in and uptake of vaccines. Public health interventions would effectively complement strategies in the clinic to increase overall coverage.

Parental Hesitancy About Routine Childhood and Influenza Vaccinations: A National Survey

BACKGROUND AND OBJECTIVES

The World Health Organization has designated vaccine hesitancy as 1 of the 10 leading threats to global health, yet there is limited current national data on prevalence of hesitancy among US parents. Among a nationally representative sample of US parents, we aimed to (1) assess and compare prevalence of hesitancy and factors driving hesitancy for routine childhood and influenza vaccination and (2) examine associations between sociodemographic characteristics and hesitancy for routine childhood or influenza vaccination.

METHODS

In February 2019, we surveyed families with children using the largest online panel generating representative US samples. After weighting, we assessed hesitancy using a modified 5-point Vaccine Hesitancy Scale and labeled parents as hesitant if they scored >3.

RESULTS

A total of 2176 of 4445 parents sampled completed the survey (response rate 49%). Hesitancy prevalence was 6.1% for routine childhood and 25.8% for influenza vaccines; 12% strongly and 27% somewhat agreed they had concerns about serious side effects of both routine childhood and influenza vaccines. A total of 70% strongly agreed that routine childhood vaccines are effective versus 26% for influenza vaccine (P < .001). In multivariable models, an educational level lower than a bachelor's degree and household income <400% of the federal poverty level predicted hesitancy about both routine childhood and influenza vaccines.

CONCLUSIONS

Almost 1 in 15 US parents are hesitant about routine childhood vaccines, whereas >1 in 4 are hesitant about influenza vaccine. Furthermore, 1 in 8 parents are concerned about vaccine safety for both routine childhood and influenza vaccines, and only 1 in 4 believe influenza vaccine is effective. Vaccine hesitancy, particularly for influenza vaccine, is prevalent in the United States.

"I can be the Judge of What's Serious": A Qualitative Pilot Study of Parents' Responses to Messaging About Side Effects of the HPV Vaccine

OBJECTIVE

Parents' concerns about vaccine safety and side effects likely contribute to low rates of human papillomavirus (HPV) vaccination among adolescents. To facilitate parent-provider discussions about the HPV vaccine, we developed and tested the content of a clinical decision support application for implementation in pediatric clinical settings. This study sought to elicit perspectives of parents and providers on the best way to communicate information on vaccine side effects.

METHODS

To understand the acceptability of the application's content, we conducted focus groups with parents (n = 11) and providers (n = 9) at three primary care clinics. Focus groups transcriptions were analyzed using iterations of deductive and inductive coding, with independent coding by two trained reviewers to improve inter-rater reliability.

RESULTS

Surprisingly, when parents reviewed screen shots of HPV vaccine safety and side effect messages, parents took exception to the expression "no evidence of serious side effects". Parents wanted side effects listed explicitly so they could decide for themselves which side effects were "serious". Parents also felt that the HPV vaccine did have serious side effects, and the wording undermined their trust in the vaccine messaging overall. Providers accepted the phrasing of side effects and did not express concerns that parents would object to the messaging.

CONCLUSIONS

Further research is needed to confirm parents' concerns with the phrasing "no serious side effects" for the HPV vaccine and to assess the impact on HPV vaccination deferral or delay.

Adherence to Timely Vaccinations in the United States

OBJECTIVES

To estimate (1) the proportion of children not adhering to the Advisory Committee on Immunization Practices (ACIP) recommended early childhood immunization schedule and (2) associations between schedule adherence, sociodemographic characteristics, and up-to-date immunization status by 19 to 35 months of age.

METHODS

We used 2014 National Immunization Survey provider-verified vaccination data to classify vaccination patterns as "recommended" (ie, in line with ACIP dose- and age-specific recommendations), "alternate" (ie, in line with either limiting the number of shots per visit or skipping at least 1 vaccine series), or "unknown or unclassifiable" (ie, not in line with ACIP recommendations or clearly limiting shots per visit or vaccine series). We evaluated the association between vaccination patterns and up-to-date status for all ACIP-recommended vaccinations (including rotavirus and hepatitis A vaccines) using Poisson regression.

RESULTS

The majority of children's patterns were classified as "recommended" (63%), with 23% and 14% following alternate or unknown or unclassifiable patterns, respectively; 58% of children were up-to-date with all ACIP-recommended immunizations by 19 to 35 months. Not being up-to-date was associated with alternate (prevalence ratio = 4.2, 95% confidence interval: 3.9-4.5) and unknown or unclassifiable (prevalence ratio = 2.4, 95% confidence interval: 2.2-2.7) patterns.

CONCLUSIONS

High vaccine coverage by 19 to 35 months of age may miss nonadherence to the recommended immunization schedule in the first 18 months of life, leaving children vulnerable to preventable diseases. With more than one-third of US children not following the ACIP schedule, targeted interventions are needed to minimize vaccine delays and disease susceptibility.

Use of Information Sources on Vaccine-Preventable Diseases in Pregnant Women: An Experience in Ferrara, Italy

The “vaccine hesitancy” and the consequent lowering of vaccination coverage have, on one hand, pushed the Italian government to reintroduce some new compulsory vaccinations for access to schools and, on the other, have imposed a greater effort on health operators to understand the causes and, consequently, to intervene with tools for promotion and health education. In Ferrara, we administered 201 non-self-filling questionnaires to 201 pregnant women within a cross-sectional multicenter study, consisting of 63 items divided into 7 sections. In particular, we wanted to investigate the correlation between the socio-demographic characteristics of the interviewees and the sources used to obtain information and, on the other side, the intention to vaccinate in relation to the perception of the diffusion and of the risk of vaccine-preventable diseases. The institutional information sources are less used by foreigners, primiparous, and women with a low education level. The perception of the severity of vaccine-preventable diseases was greater in those inquiring from institutional sources. In a public health perspective, knowing the profile of future mothers in terms of socio-demographic characteristics and of the quality of the used information channels may help to guide the choices of communication in the vaccination field.

Vaccine confidence among parents: Large scale study in eighteen European countries

BACKGROUND

Despite the fact that vaccines save 2-3 million lives worldwide every year, a percentage of children are not getting appropriately vaccinated, thus leading to disease outbreaks. One of the major reasons of low vaccine uptake in Europe is vaccine hesitancy, contributing to the recent measles outbreaks. Monitoring of vaccine hesitancy is valuable in early identification of vaccine concerns.

METHODS

We performed an eighteen country European survey on parents' attitudes and behaviors regarding their children's immunization. Parents having at least one child 1-4 years old were mostly recruited by primary care paediatricians to reply to a web-based questionnaire. The questionnaire was developed by the European Academy of Paediatrics Research in Ambulatory Setting Network steering committee, based on similar surveys. An individual level hesitancy score was constructed using the answers to 21 questions, and correlations of the score with socio-demographic characteristics and types of providers were explored. To assess inter country differences, a country level self -reported confidence was defined.

RESULTS

Fifty six percent and 24% of 5736 respondents defined themselves as "not at all hesitant", and "somewhat hesitant", respectively. Parents who consulted general practitioners were more hesitant than parents who consulted pediatricians (p < 0.05). Consultation with homeopathists was associated with the highest reported hesitancy (p < 0.05). Vaccine confidence was highest in Portugal and Cyprus, and lowest in Bulgaria and Poland.

CONCLUSION

The majority of parents in Europe believe in the importance of childhood vaccination. However, significant lack of confidence was found in certain European countries, highlighting the need for continuous monitoring, awareness and response plans. The possible influence of different types of healthcare providers on parental decisions demonstrated for the first time in our survey, calls for further research. Monitoring and continuous medical education efforts aimed mostly at those professionals who might not be likely to recommend vaccination are suggested.

Previsit Screening for Parental Vaccine Hesitancy: A Cluster Randomized Trial

OBJECTIVE

To evaluate the effect of vaccine hesitancy screening on childhood vaccine uptake.

METHODS

We conducted a cluster randomized controlled trial in pediatric primary care clinics in Washington state. Vaccine-hesitant parents (VHPs) with a healthy newborn receiving health supervision at participating clinics were eligible. VHPs were identified by using a 4-item version of the validated Parent Attitudes About Childhood Vaccines Survey (PACV). Before their child's 2- and 6-month health supervision visits, VHPs at intervention clinics completed the 15-item PACV embedded in a survey containing placebo items. Intervention providers received a summary of parents' 15-item PACV responses and interpretation of their PACV score; discretion was given to providers regarding how they acted on this information. VHPs at control clinics completed only the placebo survey items, and their child's provider received a summary of their responses; control providers remained blinded to parent VHP status. Our outcome was child immunization status at 8 months of age expressed as percent of days underimmunized. We compared outcomes in control and intervention participants using t test and linear mixed-effects regression.

RESULTS

We enrolled 24 clinics (12 in each arm) and 156 parents (65 in the intervention arm). Parent characteristics were similar across arms except more intervention (versus control) parents had a first-born child (60.9% vs 44%; P = .04). No significant difference in outcome was detected between arms (25.2% [95% confidence interval: 16.0% to 34.5%] vs 19.1% [95% confidence interval: 12.0% to 26.3%] mean days underimmunized in the intervention and control arms, respectively).

CONCLUSION

Vaccine hesitancy screening was not significantly associated with days underimmunized.

Health Information Sources, Perceived Vaccination Benefits, and Maintenance of Childhood Vaccination Schedules

Parental concerns over the safety or necessity of childhood vaccination have increased over the past decades. At the same time, there has been a proliferation of vaccine-related information available through a range of health information sources. This study investigates the associations between evaluations of health information sources, parental perceptions of childhood vaccination benefits, and the maintenance of vaccination schedules for their children. Specifically, this study aims to (a) incorporate social media into the battery of health information sources and (b) differentiate households with a childhood autism diagnosis and those without, given unsubstantiated but persistent concerns about vaccine safety and autism. Analyzing a sample of U.S. households, a total of 4,174 parents who have at least one child under the age of 18 were analyzed, including 138 of parents of households with a childhood autism diagnosis. Results show that the more the parents value interpersonal communication and magazines as sources of health information, the more they perceive vaccination benefits, and the more the value they put on television, the better they keep vaccination schedules up-to-date for their children. On the other hand, social media are negatively associated with their perceptions of vaccination benefits. Although parents of children diagnosed with autism are less likely to perceive vaccination benefits, no interaction effects with evaluations of health information sources are found on parental perceptions of vaccination benefits or maintenance of schedules.

Sociodemographic and health care factors in determining immunization defaulters among preschool children in Petaling District, Selangor: a cross-sectional study in Malaysia

BACKGROUND

Immunization is an effective public health intervention to reduce morbidity and mortality among children and it will become more effective if the child can receive the full course of recommended immunization doses. The objective of this study was to determine the prevalence of childhood immunization defaulters and its associated factors among children below 5 years attending registered child care centers in Petaling District, Selangor.

METHODS

This was a cross-sectional survey among mothers with children below 5 years from 60 registered child care centers in District of Petaling, Selangor. Data was collected by a self-administered questionnaire from a total of 1015 mothers. Simple Logistic Regression, Chi-square or Fisher's exact test were performed to determine the association between individual categorical variables and childhood immunization defaulters. Multivariate logistic regression was used to determine the predictors of childhood immunization defaulters.

RESULTS

The study showed that the prevalence rate for defaulting immunization was 20.7%. After adjusting all confounders, six statistically significant predictors of childhood immunization defaulters were determined. They were non-Muslims (aOR = 1.669, 95% CI = 1.173, 2.377, p = 0.004), mothers with diploma and below educational background (aOR = 2.296, 95% CI = 1.460, 3.610, p < 0.0001), multiple children of 5 and above in a family (aOR = 2.656, 95% CI = 1.004, 7.029, p = 0.040), mothers with younger children aged 2 years and below (aOR = 1.700, 95% CI = 1.163, 2.486, p = 0.006), long travelling time of more than 30 min to the immunization health facility (aOR = 2.303, 95% CI = 1.474, 3.599, p < 0.0001) and had delayed at least one of the immunization schedule (aOR = 2.747, 95% CI = 1.918, 3.933, p < 0.0001).

CONCLUSION

This study highlights the need of implementation of intervention programs should be intensified to improve the childhood immunization status, focusing on the Non-Muslim community, mothers with low educational level, mothers with multiple children and mothers with children aged 2 years and below. In light of the growing problem of immunization defaulters in Malaysian children, identifying mothers at risk of not completing their children immunization schedule and educating them is an important strategy to recurrent outbreaks of infectious disease in the country.

Early Childhood Vaccination Status of Preterm Infants

BACKGROUND

Preterm infants are at increased risk for vaccine-preventable infections and associated complications. Limited studies describe timely vaccination of these vulnerable infants.

METHODS

This retrospective cohort study included Washington State infants with birth hospitalizations at an urban academic medical center between 2008 and 2013. Demographic, clinical, and visit data from electronic health records were linked to vaccine data from the Washington State Immunization Information System. Completion of the recommended 7-vaccine series by 19 months of age was compared between preterm infants (born at <37 weeks' gestation) and term/postterm infants (born at 37-43 weeks' gestation) by using Pearson's χ² test and multivariable logistic regression. Secondary outcomes included 7-vaccine series completion by 36 months of age and receipt of individual vaccines in the series. Rotavirus, hepatitis A, and influenza vaccination was also assessed.

RESULTS

Of study infants (n = 10 367), 19.3% were born prematurely. Preterm infants had lower 7-vaccine series completion compared with term/postterm infants by 19 months (47.5% vs 54.0%; adjusted odds ratio 0.77 [95% confidence interval 0.65-0.90]) and 36 months (63.6% vs 71.3%; adjusted odds ratio 0.73 [95% confidence interval 0.61-0.87]). Early preterm (23-33 weeks' gestation) and late preterm (34-36 weeks' gestation) infants had a lower rate of 7-vaccine series completion compared with term/postterm infants. Full influenza vaccination coverage by 19 months also differed between groups (early preterm: 47.7%; late preterm: 41.5%; term/postterm: 44.7%; P = .02).

CONCLUSIONS

Over half of preterm infants were undervaccinated at 19 months; one-third failed to catch up by 36 months. Strategies to improve vaccination of these high-risk infants are needed.

A population-based study of maternal and infant factors influencing influenza vaccination among young children born in Colorado from 2008 to 2016

INTRODUCTION

Influenza causes significant morbidity among young children, and vaccination remains the best strategy to prevent disease. Understanding factors influencing early influenza vaccination uptake are important to identify strategies to increase vaccination rates.

OBJECTIVE

To assess maternal and neonatal factors associated with influenza vaccination among first-born children within the first two years of life.

METHODS

We conducted a retrospective population-based cohort study linking Colorado Birth Registry data and state immunization data of all live births between 2008 and 2016. The cohort was limited to singleton, first births. Multivariable logistic regression was used to assess associations between maternal and neonatal factors and influenza vaccination.

RESULTS

Among 126,763 births meeting criteria for inclusion, 50.2% were vaccinated against influenza by two years of age. Mothers of unvaccinated children were older (27 vs 26 years, p < 0.0001), married (67.8% vs 66.8%, p < 0.0001), with a college education (38.8% vs 37.2%, p < 0.0001). Influenza vaccination rates declined over time by birth year (30.5% in 2009 vs 6.8% in 2013, p < 0.0001). Children admitted to the NICU receiving oxygen with 72 h of birth were 20% less likely to be vaccinated (RR = 0.8, 95% CI: 0.67-0.96) after adjusting for maternal age, race/ethnicity, education and preterm birth. Conversely, premature births were associated with an increase in influenza vaccination by age two years (RR = 1.1, 95%CI: 1.05, 1.15).

CONCLUSIONS

Among a large population-based cohort of mother-infant pairs in Colorado using birth and immunization registry data, there were statistically significant differences in maternal factors between unvaccinated and vaccinated children with influenza in the first 2 years of life, but the differences were too small to be clinically significant. Children admitted to the NICU were 20% less likely to be vaccinated, highlighting the need to target influenza vaccination in this population once eligible. Ongoing studies are needed to explore factors associated with early influenza vaccination.

Hepatitis B Vaccination among 1999⁻2017 Birth Cohorts in Zhejiang Province: The Determinants Associated with Infant Coverage

This study aimed to investigate the coverage of hepatitis B vaccine (Hep B) and its completeness and timeliness for birth cohorts from 1999 to 2017 in Zhejiang province, East China. Demographic characteristics and vaccination records of Hep B of children born from 1 January 1999 to 31 June 2017 were extracted from the Zhejiang provincial immunization information system. The timeliness of the first dose of Hep B (Hep B1) was defined as the proportion of children who received the Hep B1 within 24 h after birth among the target population. The completeness of Hep B was defined as the proportion of children who completed the three-dose series of Hep B before 7 years of age. The demographic characteristics of the target population were described. The coverage of each dose of Hep B, the timeliness of Hep B1, and the completeness of Hep B for each birth cohort were described. A logistic regression model was applied to detect the determinants of the timeliness of Hep B1 and the completeness of Hep B vaccination. The coverage of Hep B1 increased from 90.3% to 98.3%, the coverage of Hep B2 increased from 88.8% to 96.1%, and the coverage of Hep B3 increased from 86.4% to 94.2%. The timeliness of Hep B1 increased from 80.3% to 91.3%. The completeness of Hep B increased from 81.3% to 91.5%. The determinants of timeliness of Hep B1 included children’s delivery place, immigration status, maternal education level, and economic development level of resident area. The determinants of completeness of Hep B included children’s delivery place, immigration status, maternal education level, economic development level of resident area, maternal occupation, and frequency of vaccination service. Zhejiang province had achieved significant improvements in the timely administration of Hep B1 and the completeness of Hep B. To accelerate progress toward additional reductions in the transmission of hepatitis B virus, further efforts need to be focused on improving the timeliness of Hep B1 vaccination and reducing the drop-outs among disadvantaged children with the risk factors identified in this study.

It's Complicated: The 2014-2015 U.S. Measles Outbreak and Parents' Vaccination Beliefs, Confidence, and Intentions

While it seems intuitive that highly visible vaccine-preventable disease outbreaks should impact perceptions of disease risk and facilitate vaccination, few empirical studies exist to confirm or dispel these beliefs. This study investigates the impact of the 2014-2015 Disneyland measles outbreak on parents' vaccination attitudes and future vaccination intentions. The analysis relies on a pair of public opinion surveys of American parents with at least one child under the age of six (N = 1,000 across each survey). Controlling for basic demographics, we found higher levels of reported confidence in the safety and efficacy of childhood vaccinations in our follow-up data collection. However, this confidence was also accompanied by elevated levels of concern toward childhood vaccines among American parents. We then examined how different subgroups in the population scored on these measures before and after the outbreak. We found that parents with high levels of interest in the topic of vaccines and a child who is not fully upto date with the recommended vaccination schedule reported more supportive attitudes toward vaccines. However, future intentions to follow the recommended vaccination schedule were not positively impacted by the outbreak. Possible explanations for these results and implications for vaccination outreach are discussed.

Routine vaccination coverage of children aged 1-7 years in Zhejiang province, China

BACKGROUND

This study was to evaluate the coverage, completeness and timeliness of routine vaccination among children aged 1-7 years in Zhejiang province.

METHODS

Demographic information and immunization records of 4613160 children born from Jan 1, 2010 to Dec 31, 2016 were extracted from Zhejiang provincial immunization information system (ZJIIS) on Dec 31, 2017. Vaccination coverage for each vaccine dose and completeness of different vaccine series were calculated by birth cohort, immigration status, and geographic area. The timeliness of vaccine doses scheduled before 12 months of age for the 2016 birth cohort was also examined Results: Coverage of all the vaccine doses scheduled before 12 months of age and its completeness reached the target goal of 90%. The coverage and completeness decreased substantially in vaccinations scheduled after 12 months old, and most of them were below 90%. The coverage and timeliness estimates of migrant children was lower than those of resident children and the coverage of WenZhou (WZ), Zhoushan (ZS) and Lishui (LS) was lower than other cities across all the birth cohorts. Despite high coverage rates for all antigens by age 12 months, there was a very large range of percent of vaccination delay when comparing different antigens scheduled in the first year of life for the 2016 birth cohort.

CONCLUSIONS

This study demonstrated the success and improvement of immunization program in Zhejiang province, and identified some challenges. Strategies such as assessment, feedback, incentives, and exchange program, reminder/recall activity, home visits, immunization requirement for school's enrollment could be used to reach a higher coverage of the population.

Implementing vaccine hesitancy screening for targeted education

BACKGROUND AND PURPOSE

Little research has been performed investigating the effect of using a vaccine hesitancy (VH) screening tool to address specific vaccination concerns. The purpose of this study was to determine whether using a VH screening tool in conjunction with provider discussions addressing parental concerns affected the parental intent to vaccinate (ITV).

METHODS

This study used a pretest/posttest design to measure and categorize VH and ITV.

CONCLUSIONS

The total sample size was 89. Differences between previsit and postvisit questionnaires showed mean responses for questions that measured specific VH categories had slight increases in the level of VH. A regression analysis was conducted to predict the postvisit ITV. Questions measuring parental trust in the provider, beliefs on vaccine efficacy, and beliefs about the prevalence of vaccine preventable disease (VPD) in the community predicted 72% of the postvisit ITV responses.

IMPLICATIONS FOR PRACTICE

The utilization of a VH screening tool used in conjunction with provider education in an educated and mildly VH population did not positively affect the level of VH or the parental ITV. Additional research should investigate the role of parental trust in the provider, beliefs on vaccine efficacy, and the prevalence of VPD in the community affect parental ITV.

Influences on Immunization Decision-Making among US Parents of Young Children

Objectives This study assessed influences on vaccination decisions among parents of young children and examined common vaccination information and advice sources. Methods Using panel samples of parents of children under 7 years, web-based surveys were conducted in 2012 (n = 2603) and 2014 (n = 2518). A vaccine decision-making typology (non-hesitant acceptors, hesitant acceptors, delayers, and refusers) was established and weighted population estimates of potential factors influencing parental vaccination decision (e.g., provider influence, source of information and advice) were computed by year and decision type. Results Delayers and refusers were more likely than acceptors to know someone whose child experienced a severe reaction to a vaccine or delayed/refused vaccine(s). High proportions of delayers (2012: 33.4%, 2014: 33.9%) and refusers (2012: 49.6%, 2014: 58.6%) reported selecting their healthcare provider based on whether the provider would allow them to delay/refuse vaccines. Providers were the most frequently reported trusted vaccine information source among all parents, though more often by acceptors than refusers (2012, 2014: p < 0.01). We found differing patterns of provider advice-seeking and internet as a reliable vaccine information source by group. Among those who had considered delay/refusal, trust in their healthcare provider's advice was the most common reason cited for their decision reversal. Conclusions for Practice Provider trust and communication along with varying degrees of personal-network influences likely contribute to immunization decisions of parents. Vaccine hesitant parents often seek providers amenable to accommodating their vaccine beliefs. Providers may benefit from vaccine communication training as their recommendations may influence hesitant parents to immunize their children.

Increasing Vaccination: Putting Psychological Science Into Action

Vaccination is one of the great achievements of the 20th century, yet persistent public-health problems include inadequate, delayed, and unstable vaccination uptake. Psychology offers three general propositions for understanding and intervening to increase uptake where vaccines are available and affordable. The first proposition is that thoughts and feelings can motivate getting vaccinated. Hundreds of studies have shown that risk beliefs and anticipated regret about infectious disease correlate reliably with getting vaccinated; low confidence in vaccine effectiveness and concern about safety correlate reliably with not getting vaccinated. We were surprised to find that few randomized trials have successfully changed what people think and feel about vaccines, and those few that succeeded were minimally effective in increasing uptake. The second proposition is that social processes can motivate getting vaccinated. Substantial research has shown that social norms are associated with vaccination, but few interventions examined whether normative messages increase vaccination uptake. Many experimental studies have relied on hypothetical scenarios to demonstrate that altruism and free riding (i.e., taking advantage of the protection provided by others) can affect intended behavior, but few randomized trials have tested strategies to change social processes to increase vaccination uptake. The third proposition is that interventions can facilitate vaccination directly by leveraging, but not trying to change, what people think and feel. These interventions are by far the most plentiful and effective in the literature. To increase vaccine uptake, these interventions build on existing favorable intentions by facilitating action (through reminders, prompts, and primes) and reducing barriers (through logistics and healthy defaults); these interventions also shape behavior (through incentives, sanctions, and requirements). Although identification of principles for changing thoughts and feelings to motivate vaccination is a work in progress, psychological principles can now inform the design of systems and policies to directly facilitate action.

Initiation and completion rates of inactivated hepatitis A vaccination among children born between 2005 and 2014 in Zhejiang province, east China

OBJECTIVES

To evaluate the initiation and completion and timeliness of inactivated hepatitis A vaccine (HAV-I) series, to identify the missed opportunities for HAV-I series, and to examine determinants associated with the completion of HAV-I.

METHODS

Children born from 1 January 2005 to 31 December 2014 and registered in Zhejiang provincial immunization information system (ZJIIS), were enrolled in this study. Descriptive statistics were used to describe the initiation and completion, the timeliness and the missed opportunities for HAV-I. Logistic regression analysis was applied to explore the determinants of the completeness of HAV-I.

RESULTS

The initiation rate of HAV-I increased from 8.1% for the 2005 birth cohort to 13.2% for the 2014 birth cohort. The completion rate of HAV-I increased from 4.2% for the 2005 birth cohort to 7.8% for the 2014 birth cohort. The timeliness rate of the 1^st dose of HAV-I increased from 38.2% for the 2005 birth cohort to 57.9% for the 2014 birth cohort. The timeliness rate the 2^nd dose of HAV-I increased from 17.3% for the 2005 birth cohort to 35.3% for the 2014 birth cohort. 78.3% of the children who did not initiated any hepatitis A vaccine, had at least one immunization clinic visit after their 18^th month of age. 36.0% of the children who received the 1^st dose of HAV-I but did not receive the 2^nd dose, had at least one immunization clinic visit after 6 months from the date of receiving the 1^st dose of HAV-I. The determinants including year of birth, socio-economic development level of municipals, place of delivery, receipt of MMR/VarV were associated with the completion of HAV-I series.

CONCLUSION

Although the initiation and completion of HAV-I series had improved in recent years, these indicators were still lower than those for other vaccines scheduled at the similar age. It is important for providers to identify every opportunity for HAV-I vaccination and to assure that children get protection from this vaccine-preventable disease.