Parental decline of pneumococcal vaccination and risk of pneumococcal related disease in children

Strategies for Improving Vaccine Communication and Uptake

Vaccines have led to a significant decrease in rates of vaccine-preventable diseases and have made a significant impact on the health of children. However, some parents express concerns about vaccine safety and the necessity of vaccines. The concerns of parents range from hesitancy about some immunizations to refusal of all vaccines. This clinical report provides information about the scope and impact of the problem, the facts surrounding common vaccination concerns, and the latest evidence regarding effective communication techniques for the vaccine conversation. After reading this clinical report, readers can expect to: Understand concepts and underlying determinants of vaccine uptake and vaccine hesitancy.Understand the relationship between vaccine hesitancy and costs of preventable medical care.Recognize and address specific concerns (eg, vaccine safety) with caregivers when hesitancy is present.

Why Turkish Parents Refuse Childhood Vaccination? A Qualitative Study

BACKGROUND

Anti-vaccination is spreading among parents. In 2017, 23000 families in Turkey refused vaccinations for their children. Meanwhile an increase in infectious diseases was observed, which might be caused by vaccination rejection. The reasons why families do not vaccinate their children may be very different, such as side effects, or advocation for "healthy life" by gurus. However, the real reasons for vaccine refusal are unknown. Our aim is to determine the reasons for anti-vaccination in Turkey.

METHODS

In order to reveal the real reasons for not taking the vaccine, we planned to conduct interviews with the representatives of the vaccine rejection group using qualitative research methodology with the "grounded theory" method. We searched some anti-vaccination blogs to find candidates for interviews. Within the scope of our study, parental concerns about vaccinations were classified by analyzing the data obtained from semi-structured questions and interviews recorded with voice recorders in face-to-face interviews with 21 parents in 13 cities of Turkey.

RESULTS

The obtained findings were classified under the headings of ''mistrust'', ''vaccine efficacy-importance'', ''decision-making processes - bases'', and ''law-ethics''. Mistrust was the main theme, almost singularly, as the most important reason for vaccine rejection. The salient reasons for mistrusts were: Companies which produce vaccines especially international companies because of conspiratory beliefs; health authorities, because of the belief about non-transparency in epidemiologic data, immunization council etc. and healthcare professionals, because of their non-communicative and non-concerned attitude.

CONCLUSION

Mistrust is hard to overcome. The beliefs of the patients cannot be easily changed. As a result of our study, we made some recommendations for health authorities, healthcare professionals, companies and other related stakeholders.

Knowledge, attitude, and hesitancy towards COVID-19 vaccine among university students of Bangladesh

Global vaccination coverage is an urgent need to recover the recent pandemic COVID-19. However, people are concerned about the safety and efficacy of this vaccination program. Thus, it has become crucial to examine the knowledge, attitude, and hesitancy towards the vaccine. An online cross-sectional survey was conducted among university students of Bangladesh. Total of 449 university students participated. Most of these students used the internet (34.74%), social media (33.41%), and electronic media (25.61%) as a source of COVID-19 vaccine information. Overall, 58.13% and 64.81% of university students reported positive knowledge and attitude towards the COVID-19 vaccine. 54.34% of these students agreed that the COVID-19 vaccine is safe and effective. 43.88% believed that the vaccine could stop the pandemic. The Spearman’s Rank correlation determined the positive correlation between knowledge and attitude. The negative correlation was determined between positive knowledge and hesitancy, and positive attitude and hesitancy. University students with positive knowledge and attitude showed lower hesitancy. Multiple logistic regression analyses determined the university type and degree major as the predictors of knowledge, whereas only degree major was the predictor of attitudes. 26.06% of the study population showed their hesitancy towards the vaccine. University type and degree major were also determined as predictors of this hesitancy. They rated fear of side effects (87.18%) and lack of information (70.94%) as the most reasons for the hesitancy. The findings from this study can aid the ongoing and future COVID-19 vaccination plan for university students. The national and international authorities can have substantial information for a successful inoculation campaign.

Parental Willingness to Vaccinate Their Children Against SARS-CoV-2 in Jordan: An Explanatory Cross-Sectional Study

Background

Successful control of the COVID-19 pandemic is largely dependent on vaccine administration to epidemiologically influential groups, including children. Considering that pediatric population comprises a significant portion on the population in developing countries, and their risk of infection and spreading the disease has been underestimated, it is crucial to investigate parental willingness to administer SARS-CoV-2 vaccine to their children between 5 and 11 years old. This study investigates the prevalence and determinants of parental willingness towards vaccinating their children (5–12 years old) against COVID-19 in a developing country setting, Jordan.

Methods

A cross-sectional study, conducted between October and November 2021, utilized online Google Forms to collect data on parents’ background characteristics, willingness to vaccinate their children, SARS-CoV-2, infection and vaccine, risk perception, and factors affecting decision to vaccinate.

Results

A total of 564 parents completed the questionnaire; 82.8% were mothers, 85.3% were 30 years of age or older, and 75.9% had bachelor’s degrees or higher. Only 25.4% of parents reported willingness to vaccinate their 5–12 years old children against SARS-CoV-2. Lower parental age, higher income, and having health insurance coverage increased parental willingness. Among participants vaccinated against COVID-19, only 29.0% were willing to vaccinate their children. Healthcare providers’ trust and vaccine recommendations by pediatricians increased parental willingness. COVID-19 risk perception seems to have negative effects on parental willingness.

Conclusion

A significant proportion of parents in Jordan indicated hesitancy towards administering COVID-19 vaccine for their children. Concerns about vaccine safety and trust in the healthcare system appear to be the most important predictors of parents’ hesitancy. Effective vaccine campaigns should focus on risk perception and communication and should consider parental socio-demographic characteristics.

Vaccine Administration in Children's Hospitals

OBJECTIVES

To examine inpatient vaccine delivery across a national sample of children's hospitals.

METHODS

We conducted a retrospective cohort study examining vaccine administration at 49 children's hospitals in the Pediatric Health Information System database. Children <18 years old admitted between July 1, 2017, and June 30, 2019, and age eligible for vaccinations were included. We determined the proportion of hospitalizations with ≥1 dose of any vaccine type administered overall and by hospital, the type of vaccines administered, and the demographic characteristics of children who received vaccines. We calculated adjusted hospital-level rates for each vaccine type by hospital. We used logistic and linear regression models to examine characteristics associated with vaccine administration.

RESULTS

There were 1 185 667 children and 1 536 340 hospitalizations included. The mean age was 5.5 years; 18% were non-Hispanic Black, and 55% had public insurance. There were ≥1 vaccine doses administered in 12.9% (95% confidence interval: 12.8-12.9) of hospitalizations, ranging from 1% to 45% across hospitals. The most common vaccines administered were hepatitis B and influenza. Vaccine doses other than the hepatitis B birth dose and influenza were administered in 1.9% of hospitalizations. Children had higher odds of receiving a vaccine dose other than the hepatitis B birth dose or influenza if they were <2 months old, had public insurance, were non-Hispanic Black race, were medically complex, or had a length of stay ≥3 days.

CONCLUSIONS

In this national study, few hospitalizations involved vaccine administration with substantial variability across US children's hospitals. Efforts to standardize inpatient vaccine administration may represent an opportunity to increase childhood vaccine coverage.

Vaccine timeliness and prevalence of undervaccination patterns in children ages 0-19 months, U.S., National Immunization Survey-Child 2017

OBJECTIVES

Typically, early childhood vaccination coverage in the U.S. is measured as the proportion of children by age 24 months who completed recommended vaccine series. However, these measures do not reflect whether vaccine doses were received at the ages recommended by the U.S. Advisory Committee on Immunization Practices, or whether children received vaccines concomitantly, per the ACIP recommended schedule. This study's objective was to quantify vaccine timeliness and prevalence of specific patterns of undervaccination in U.S. children ages 0-19 months.

METHODS

Using 2017 National Immunization Survey-Child data, we calculated days undervaccinated for the combined 7-vaccine series and distinguished undervaccination patterns indicative of parental vaccine hesitancy, such as spreading out vaccines across visits ("shot-limiting") or starting some but not all recommended vaccine series ("selective vaccination"), from other non-hesitancy patterns, such as missing final vaccine doses or receiving all doses, with some or all late. We measured associations between demographic, socioeconomic and other characteristics with undervaccination patterns using multivariable log-linked binomial regression. Analyses accounted for the complex survey design.

RESULTS

Among n = 15,333 U.S. children, only 41.2% received all recommended vaccine doses on-time by age 19 months. Approximately 20.9% of children had an undervaccination pattern suggestive of parental vaccine hesitancy, and 36.2% had other undervaccination non-hesitancy patterns. Uninsured children and those with lower levels of maternal education were more likely to exhibit undervaccination patterns suggestive of parental hesitancy. Lower levels of maternal education were also associated with other non-hesitancy undervaccination patterns.

CONCLUSIONS

More than half of children in the U.S. are undervaccinated at some point by 19 months of age. Ongoing assessment of vaccine timeliness and immunization schedule adherence could facilitate timely and targeted public health interventions in populations with high levels of undervaccination.

Prevalence and Determinants of Vaccine Hesitancy in Aseer Region, Saudi Arabia

Objectives

This study aimed to assess the awareness of the general population regarding vaccines to determine the prevalence of vaccine hesitancy in Aseer Region in the southern part of Saudi Arabia.

Methods

A descriptive cross-sectional approach was used, targeting all parents in Aseer Region. The study was carried out from January to April 2020. The data for this study were collected using a structured questionnaire, which was developed by the researchers after an intensive literature review and consultation with experts. The questionnaire covered aspects such as parents’ sociodemographic data, their awareness regarding vaccine safety and efficacy for children and their attitude and adherence to children’s vaccination, including their hesitancy towards vaccines.

Results

The survey included 796 participants (response rate: 100%) whose ages ranged from 18 to 55 years. Two-thirds (63.4%) of the participants were female. Regarding vaccination adherence and hesitancy among participants, more than three-quarters completely adhered to the vaccination schedule for their children, and only 3.9% were non-adherent. With regards to participants’ awareness regarding vaccine safety and efficacy for children, 89.3% agreed that vaccination keeps children healthy, 84.2% reported that vaccines are safe and effective for children and 83.4% reported that all scheduled vaccines in Saudi Arabia are effective.

Conclusion

Vaccine hesitancy among participants was not low, and this should be taken into account notwithstanding their high awareness levels. The recorded antivaccine action was mostly related to vaccine safety and not its efficacy.

Spatial-temporal patterns of childhood immunization in New Zealand (2006-2017): an improving pattern but not for all?

BACKGROUND

Declining childhood immunization represents a serious public health problem globally and in New Zealand. To guide efforts to increase immunization coverage, this study monitors nationwide change in immunization coverage since the introduction of the National Immunisation Register (NIR) in 2005 and spatiotemporal patterns of immunization coverage from 2006 to 2017.

METHODS

The study population consisted of 4 482 499 individual immunization records that were obtained from the NIR (2005-2017). Data on yearly and average immunization coverage in census area units (CAUs) in New Zealand were calculated by milestone age (6/8/12/18/24/60/144 months). Data for 2005 were excluded due to missing records in the introductory period of the NIR. We analyzed spatial and spatiotemporal patterns using Gi* and SaTScan methods.

RESULTS

Immunization coverage improved since the introduction of the NIR in 2005, reaching a peak in 2014 and 2015 with a slight decrease in 2016 and 2017. Well and insufficiently immunized areas were identified with spatial autocorrelation analyses highlighting several hot- and cold-spots. Comparison of CAUs with neighbouring CAUs allowed for the identification of places where immunization coverage was significantly higher or lower than expected, over both time and space.

CONCLUSION

We provide the first spatiotemporal analysis of childhood immunization in New Zealand that utilizes a large sample of over 4.4 million individual immunization records. Our spatial analyses enable policymakers to understand the development of childhood immunization coverage and make more effective prevention strategies in New Zealand.

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.

Association of Bacteremia with Vaccination Status in Children Aged 2 to 36 Months

OBJECTIVE

To determine the association between bacteremia and vaccination status in children aged 2-36 months presenting to a pediatric emergency department.

STUDY DESIGN

Retrospective cohort study of children aged 2-36 months with blood cultures obtained in the pediatric emergency department between January 2013 and December 2017. The exposure of interest was immunization status, defined as number of Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae vaccinations, and the main outcome positive blood culture. Subjects with high-risk medical conditions were excluded.

RESULTS

Of 5534 encounters, 4742 met inclusion criteria. The incidence of bacteremia was 1.5%. The incidence of contaminated blood culture was 5.0%. The relative risk of bacteremia was 0.79 (95% CI 0.39-1.59) for unvaccinated and 1.20 (95% CI 0.52-2.75) for undervaccinated children relative to those who had received age-appropriate vaccines. Five children were found to have S pneumoniae bacteremia and 1 child had Hib bacteremia; all of these subjects had at least 3 sets of vaccinations. No vaccine preventable pathogens were isolated from blood cultures of unvaccinated children. We found no S pneumoniae or Hib in children 2-6 months of age who were not fully vaccinated due to age (95% CI 0-0.13%) and the contamination rate in this group was high compared with children 7-36 months (6.6% vs 3.7%).

CONCLUSIONS

Bacteremia in young children is an uncommon event. Contaminated blood cultures were more common than pathogens. Bacteremia from S pneumoniae or Hib is uncommon and, in this cohort, was independent of vaccine status.

Addressing Parental Vaccine Hesitancy and Other Barriers to Childhood/Adolescent Vaccination Uptake During the Coronavirus (COVID-19) Pandemic

Routine childhood immunizations are proven to be one of the most effective public health interventions at controlling numerous deadly diseases. Therefore, the CDC recommends routine immunizations for children and adolescent populations against vaccine-preventable diseases e.g., tetanus, pertussis, diphtheria, etc. This current review sought to examine barriers to pediatric vaccine uptake behaviors during the COVID-19 pandemic. We also explored the implications for parental vaccine hesitancy/delay during an ongoing health crisis and proposed recommendations for increasing vaccine confidence and compliance. Our review determined that the receipt for vaccinations steadily improved in the last decade for both the United States and Tennessee. However, this incremental progress has been forestalled by the COVID-19 pandemic and other barriers i.e. parental vaccine hesitancy, social determinants of health (SDoH) inequalities, etc. which further exacerbate vaccination disparities. Moreover, non-compliance to routine vaccinations could cause an outbreak of diseases, thereby, worsening the ongoing health crisis and already strained health care system. Healthcare providers are uniquely positioned to offer effective recommendations with presumptive languaging to increase vaccination rates, as well as, address parental vaccine hesitancy. Best practices that incorporate healthcare providers' quality improvement coaching, vaccination reminder recall systems, adherence to standardized safety protocols (physical distancing, hand hygiene practices, etc.), as well as, offer telehealth and outdoor/drive-through/curbside vaccination services, etc. are warranted. Additionally, a concerted effort should be made to utilize public health surveillance systems to collect, analyze, and interpret data, thereby, ensuring the dissemination of timely, accurate health information for effective health policy decision-making e.g., vaccine distribution, etc.

Prevalence and correlates of vaccine attitudes and behaviors in a cohort of low-income mothers

The US is facing a rise in vaccine hesitancy, delay, and refusal, though little is known about these outcomes in socio-economically disadvantaged populations. This study examines the prevalence and correlates of vaccine attitudes and behaviors in a diverse cohort of low-income mothers receiving home visiting services. Survey data were collected from 813 recipients of evidence-based home visiting services in Wisconsin from 2013 to 2018. Analyses were performed to describe outcome measures of vaccine attitudes and self-reported completion, and multivariate regressions were used to test associations between vaccine-related outcomes and hypothesized correlates. Most women (94%) reported their children were up to date on vaccines; 14.3% reported having ever delayed vaccination. A small minority disagreed that vaccines are important (5.0%), effective (5.4%), and safe (6.2%), though a larger proportion responded ambivalently (10.9%–21.9%). Participants with greater trust in health care providers reported more positive overall vaccine attitudes (B = 0.24; 95% CI = 0.17, 0.31), a lower likelihood of vaccine delay (OR = 0.57; 95% CI = 0.46, 0.73), and a greater likelihood of being up to date on vaccines (OR = 1.79, 95% CI = 1.30, 2.44). Women with greater trust in a home visitor also rated vaccines more positively (B = 0.09; 95% CI = 0.02, 0.15), and women who reported better mental health were more likely to report their children were up to date (OR = 1.05; 95% CI = 1.02, 1.09). Compared to non-Hispanic whites, American Indians and non-Hispanic blacks had poorer vaccine-related outcomes. More research on vaccine attitudes and behaviors among higher-risk populations is needed to develop tailored strategies aimed at addressing vaccine hesitancy and underimmunization.

'Presumptively Initiating Vaccines and Optimizing Talk with Motivational Interviewing' (PIVOT with MI) trial: a protocol for a cluster randomised controlled trial of a clinician vaccine communication intervention

INTRODUCTION

A key contributor to underimmunisation is parental refusal or delay of vaccines due to vaccine concerns. Many clinicians lack confidence in communicating with vaccine-hesitant parents (VHP) and perceive that their discussions will do little to change parents' minds. Improving clinician communication with VHPs is critical to increasing childhood vaccine uptake.

METHODS AND ANALYSIS

We describe the protocol for a cluster randomised controlled trial to test the impact of a novel, multifaceted clinician vaccine communication strategy on child immunisation status. The trial will be conducted in 24 primary care practices in two US states (Washington and Colorado). The strategy is called Presumptively Initiating Vaccines and Optimizing Talk with Motivational Interviewing (PIVOT with MI), and involves clinicians initiating the vaccine conversation with all parents of young children using the presumptive format, and among those parents who resist vaccines, pivoting to using MI. Our primary outcome is the immunisation status of children of VHPs at 19 months, 0 day of age expressed as the percentage of days underimmunised from birth to 19 months for 22 doses of eight vaccines recommended during this interval. Secondary outcomes include clinician experience communicating with VHPs, parent visit experience and clinician adherence to the PIVOT with MI communication strategy.

ETHICS AND DISSEMINATION

This study is approved by the following institutional review boards: Colorado Multiple Institutional Review Board, Washington State Institutional Review Board and Swedish Health Services Institutional Review Board. Results will be disseminated through peer-reviewed manuscripts and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03885232.

Vaccination Status and Adherence to Quality Measures for Acute Respiratory Tract Illnesses

OBJECTIVES

To assess the relationship between vaccination status and clinician adherence to quality measures for children with acute respiratory tract illnesses.

METHODS

We conducted a multicenter prospective cohort study of children aged 0 to 16 years who presented with 1 of 4 acute respiratory tract illness diagnoses (community-acquired pneumonia, croup, asthma, and bronchiolitis) between July 2014 and June 2016. The predictor variable was provider-documented up-to-date (UTD) vaccination status. Our primary outcome was clinician adherence to quality measures by using the validated Pediatric Respiratory Illness Measurement System (PRIMES). Across all conditions, we examined overall PRIMES composite scores and overuse (including indicators for care that should not be provided, eg, C-reactive protein testing in community-acquired pneumonia) and underuse (including indicators for care that should be provided, eg, dexamethasone in croup) composite subscores. We examined differences in length of stay, costs, and readmissions by vaccination status using adjusted linear and logistic regression models.

RESULTS

Of the 2302 participants included in the analysis, 92% were documented as UTD. The adjusted mean difference in overall PRIMES scores by UTD status was not significant (adjusted mean difference -0.3; 95% confidence interval: -1.9 to 1.3), whereas the adjusted mean difference was significant for both overuse (-4.6; 95% confidence interval: -7.5 to -1.6) and underuse (2.8; 95% confidence interval: 0.9 to 4.8) composite subscores. There were no significant adjusted differences in mean length of stay, cost, and readmissions by vaccination status.

CONCLUSIONS

We identified lower adherence to overuse quality indicators and higher adherence to underuse quality indicators for children not UTD, which suggests that clinicians "do more" for hospitalized children who are not UTD.

Under-immunization of pediatric transplant recipients: a call to action for the pediatric community

Vaccine-preventable infections (VPIs) are a common and serious complication following transplantation. One in six pediatric solid organ transplant recipients is hospitalized with a VPI in the first 5 years following transplant and these hospitalizations result in significant morbidity, mortality, graft injury, and cost. Immunizations are a minimally invasive, cost-effective approach to reducing the incidence of VPIs. Despite published recommendations for transplant candidates to receive all age-appropriate immunizations, under-immunization remains a significant problem, with the majority of transplant recipients not up-to-date on age-appropriate immunizations at the time of transplant. This is extremely concerning as the rate for non-medical vaccine exemptions in the United States (US) is increasing, decreasing the reliability of herd immunity to protect patients undergoing transplant from VPIs. There is an urgent need to better understand barriers to vaccinating this population of high-risk children and to develop effective interventions to overcome these barriers and improve immunization rates. Strengthened national policies requiring complete age-appropriate immunization for non-emergent transplant candidates, along with improved multi-disciplinary immunization practices and tools to facilitate and ensure complete immunization delivery to this high-risk population, are needed to ensure that we do everything possible to prevent infectious complications in pediatric transplant recipients.

Vaccination Status and Resource Use During Hospital Visits for Respiratory Illnesses

OBJECTIVES

To evaluate variation in resource use for children with acute respiratory tract illness (ARTI) by vaccination status.

METHODS

We conducted a retrospective cohort study of children 0 to 16 years of age at 5 children's hospitals with 1 of 4 ARTI diagnoses (pneumonia, croup, asthma, and bronchiolitis) between July 2014 and June 2016. The predictor variable was provider-documented up-to-date (UTD) vaccination status (yes or no). Outcomes were receipt of each of the following tests or treatments (yes or no): complete blood cell count, blood cultures, C-reactive protein (CRP) level testing, viral testing, influenza testing, pertussis testing, chest radiographs, neck radiographs, antibiotics, and corticosteroids. We generated multivariable logistic regression models to examine the associations between our predictor and outcomes.

RESULTS

Of the 2302 participants included in analysis, 568 (25%) were diagnosed with pneumonia, 343 (15%) were diagnosed with croup, 653 (28%) were diagnosed with asthma, and 738 (32%) were diagnosed with bronchiolitis. Most (92%) vaccination statuses were documented as UTD. Across conditions, children whose vaccination status was documented as not UTD had higher adjusted odds of receiving a complete blood cell count, blood culture, CRP level testing, and influenza testing (P < .001). Children with pneumonia whose vaccination status was documented as not UTD had higher adjusted odds of receiving CRP level testing and influenza testing (P < .001). Children with croup whose vaccination status was documented as not UTD had higher adjusted odds of receiving blood cultures (P < .001).

CONCLUSIONS

Children with ARTI whose vaccination status was documented as not UTD had higher odds of undergoing laboratory testing compared with children whose vaccination status was documented as UTD.

MomsTalkShots: An individually tailored educational application for maternal and infant vaccines

INTRODUCTION

The development and initial assessment in a clinical setting of a theory-driven, individually tailored educational application (app), MomsTalkShots, focused on increasing uptake of maternal and infant vaccines is described.

METHODS

MomsTalkShots algorithmically tailored videos based on parent needs to deliver an intervention that was specifically responsive to individual vaccine attitudes, beliefs and intentions, demographics, and source credibility. MomsTalkShots was evaluated among 1103 pregnant women recruited from 23 geographically and socio-demographically diverse obstetrician-gynecologist offices in Georgia and Colorado in 2017. Self-reported information needs were assessed pre-and post-videos and participants self-reported factors related to usability and analyzed in 2018.

RESULTS

The vast majority of women reported MomsTalkShots was helpful (95%), trustworthy (94%), interesting (97%) and clear to understand (99%), none of which varied by demographics or parity. Reported usability was slightly lower among vaccine hesitant women, yet the majority reported MomsTalkShots was helpful (91%), trustworthy (85%), interesting (97%) and clear (99%). The majority of women (72%) who did not have enough vaccine information pre-videos reported enough information post-videos.

CONCLUSIONS

MomsTalkShots was designed to provide individually tailored vaccine information to pregnant women from a population with varied vaccine intentions, confidence and vaccine concerns. MomsTalkShots was extremely well-received among pregnant women, even among women who were initially vaccine hesitant and did not intend to vaccinate themselves and their infants according to the recommended immunization schedule. Next steps include evaluation to assess impact on vaccine uptake and expansion to adolescent and adult vaccines.

Accuracy of Provider-Documented Child Immunization Status at Hospital Presentation for Acute Respiratory Illness

OBJECTIVES

To assess (1) the accuracy of child immunization status documented by providers at hospital presentation for acute respiratory illness and (2) the association of provider-documented up-to-date (UTD) status with immunization receipt during and after hospitalization.

METHODS

We conducted a retrospective cohort analysis of children ≤16 years old treated for asthma, croup, bronchiolitis, or pneumonia at a children's hospital between July 2014 and June 2016. Demographics, clinical characteristics, and provider-documented UTD immunization status (yes or no) at presentation were obtained from the medical record. We compared provider-documented UTD status to the gold standard: the child's UTD status as documented in the Washington State Immunization Information System (WAIIS). The sensitivity, specificity, and positive predictive value of provider-documented UTD status were calculated. We assessed the association of provider-documented UTD status and immunization during and within 30 days posthospitalization using multivariable logistic regression.

RESULTS

Among 478 eligible children, 450 (94%) had provider-documented UTD status at hospital presentation and an active WAIIS record. Overall, 92% and 42% were UTD by provider documentation and WAIIS records, respectively, with provider-documented UTD status having 98.4% sensitivity (95% confidence interval [CI]: 95.4%-99.7%), 12.2% specificity (95% CI: 8.5%-16.8%), and 44.6% positive predictive value (95% CI: 39.7%-49.5%). Per WAIIS records, 20% and 44% of children who were due for vaccines received a vaccine during or within 30 days posthospitalization, respectively. There was no significant association between provider-documented UTD status and immunization during or after hospitalization.

CONCLUSIONS

Provider-documented UTD immunization status at hospital presentation for children with respiratory illnesses overestimates UTD status, creating missed opportunities for immunization during and after hospitalization.

Addressing Parents' Vaccine Concerns: A Randomized Trial of a Social Media Intervention

INTRODUCTION

Successful strategies are needed to address parental vaccine hesitancy, a significant public health issue. The study objective was to assess whether an Internet-based platform with vaccine information and interactive social media components improved parents' vaccine-related attitudes.

STUDY DESIGN

A three-arm RCT.

SETTING/PARTICIPANTS

The study was conducted in a large Colorado integrated healthcare organization. Parents were enrolled during September 2013 through October 2015 and followed through November 2016; data were analyzed in 2017. Parents, recruited during pregnancy, were given a survey about vaccine-related attitudes at enrollment (i.e., baseline) and when their child was aged 3-5 months and 12-15 months (Timepoints 1 and 2, respectively). Parental vaccine hesitancy was assessed at baseline.

INTERVENTION

Study participants were randomized to the following: a study website with vaccine information and social media components (VSM arm); a website with vaccine information only (VI); or usual care.

MAIN OUTCOME MEASURES

Change in parental vaccine attitudes over time by baseline degree of vaccine hesitancy.

RESULTS

Among 1,093 study participants, 945 (86.5%) completed all three surveys. Comparing baseline with Timepoint 1 among vaccine-hesitant parents, the VSM and VI arms were associated with significant improvements in attitudes regarding vaccination benefits compared to usual care (VSM mean change 0.23 on a 5-point scale, 95% CI=0.05, 0.40, VI mean change 0.22, 95% CI=0.04, 0.40). Comparing baseline with Timepoint 2 among hesitant parents, the VSM and VI arms were also associated with significant reductions in parental concerns about vaccination risks compared to usual care (VSM mean change -0.37, 95% CI= -0.60, -0.14, VI mean change -0.31, 95% CI= -0.55, -0.07). Self-efficacy around vaccine decision making also improved among vaccine-hesitant parents. No intervention effect was observed among parents not vaccine-hesitant at baseline.

CONCLUSIONS

Among vaccine-hesitant parents, an Internet-based intervention improved parents' attitudes about vaccines.

TRIAL REGISTRATION

This study was registered at www.clinicaltrials.gov NCT01873040.

Impact of Childhood Vaccine Discussion Format Over Time on Immunization Status

OBJECTIVE

Presumptive formats to initiate childhood vaccine discussions (eg, "Well, we have to do some shots") have been associated with increased vaccine acceptance after one visit compared to participatory formats (eg, "How do you feel about vaccines?"). We characterize discussion format patterns over time and the impact of their repeated use on vaccine acceptance.

METHODS

We conducted a longitudinal prospective cohort study of children of vaccine-hesitant parents enrolled in a Seattle-based integrated health system. After the child's 2-, 4-, and 6-month visits, parents reported the format their child's provider used to begin the vaccine discussion (presumptive, participatory, or other). Our outcome was the percentage of days underimmunized of the child at 8 months old for 6 recommended vaccines. We used linear regression and generalized estimating equations to test the association of discussion format and immunization status.

RESULTS

We enrolled 73 parent-child dyads and obtained data from 82%, 73%, and 53% after the 2-, 4-, and 6-month visits, respectively. Overall, 65% of parents received presumptive formats at ≥1 visit and 42% received participatory formats at ≥1 visit. Parental receipt of presumptive formats at 1 and ≥2 visits (vs no receipt) was associated with significantly less underimmunization of the child, while receipt of participatory formats at ≥2 visits was associated with significantly more underimmunization. Visit-specific use of participatory (vs presumptive) formats was associated with a child being 10.1% (95% confidence interval, 0.3, 19.8; P = .04) more days underimmunized (amounting to, on average, 98 more days underimmunized for all 6 vaccines combined).

CONCLUSIONS

Presumptive (vs participatory) discussion formats are associated with increased immunization.

Vaccination Perceptions of College Students: With and without Vaccination Waiver

Introduction

The resurgence of vaccine preventable diseases occurs more often among intentionally unvaccinated individuals, placing at direct risk young adults not caught up on vaccinations. The objectives of this study were to characterize the sociodemographic characteristics of young adults with and without vaccination waivers and identify their perceived benefits, barriers, and influencers of vaccination.

Methods

Young adults (n = 964) from a Midwestern rural university responded to a survey (fall 2015-spring 2016) designed to identify their perception toward vaccination. Instrument consistency was measured using the Cronbach α-scores. The Chi-square test was used to test any sociodemographic differences and Mann-Whitney U-tests results for differences between exempt and non-exempt students. Analysis occurred in spring 2017.

Results

A little over one-third of young adults with a vaccination waiver were not up to date on their vaccinations, and think that vaccinations can cause autism. The biggest identifiable benefit was effective control against disease. The surveyed young adults ranked the out of pocket cost associated with vaccination as the most important barrier and safe and easy to use vaccines as the most important influencer of vaccination.

Conclusion

Young adults who have had a vaccination waiver appear to not be up to date on their vaccinations. Vaccine administration programs, such as university campus clinics, would benefit from addressing perceptions unique to young adults with and without a vaccine waiver. This would subsequently better provide young adults a second shot for getting appropriately caught up on vaccinations.

Factors Associated With Pediatrician Responses to Alternative Immunization Schedule Requests

We conducted a cross-sectional online survey among 4 chapters of the American Academy of Pediatrics from July through October 2014 to describe characteristics of pediatricians and practices associated with practice-level responses to alternative immunization schedule requests. Among 374 pediatricians, 58% reported frequent alternative immunization schedule requests and 24% reported feeling comfortable using them. Pediatricians who work in practices that accommodate alternative immunization schedule requests have increased odds of having a high frequency of alternative immunization schedule requests, and beliefs that relationships with families would be negatively affected if they refused requests. Practices that discontinue care to families who request alternative immunization schedules have increased odds of being a private group practice and having a formal office vaccine policy. Pediatricians are frequently asked to use alternative immunization schedules and many are not comfortable using them. Practice-level responses to alternative immunization schedules are associated with characteristics of pediatricians and practices.

Patterns of childhood immunization and all-cause mortality

BACKGROUND

Evidence supports the safety of the recommended childhood immunization schedule as a whole. However, additional research is warranted as parents' refusing or delaying vaccinations has increased in recent years. All-cause mortality has been identified as a priority outcome to study in the context of the recommended immunization schedule.

METHODS

We included children born January 1, 2004 through December 31, 2009, enrolled in the Vaccine Safety Datalink (VSD) from birth through 18 months of age. We examined vaccination patterns during the first 18 months of life among 8 vaccines, and identified deaths occurring between 19 and 48 months of age. We excluded children with complex chronic conditions, contraindications to vaccination, and deaths due to injuries, congenital anomalies, or diseases with onset prior to 19 months of age. We calculated mortality rates among children with different patterns of immunization, and incidence rate ratios (IRR) using the Cox proportional hazards model for children vaccinated according to the schedule versus undervaccinated children, adjusting for outpatient healthcare utilization, influenza vaccination, sex, and VSD site.

RESULTS

Among 312,388 children in the study, 199,661 (64%) were vaccinated according to the schedule, and 112,727 (36%) were delayed or not vaccinated for at least one vaccine dose. Of 18 deaths eligible for analysis, 11 occurred in children following the schedule (2.28 per 100,000 person-years), and seven occurred in undervaccinated children (2.57 per 100,000 person-years). Mortality rates among children following the schedule were not significantly different from those of undervaccinated children when excluding deaths with unknown causes (IRR = 1.29, 95% CI = 0.33-4.99), as well as when including deaths with unknown causes (IRR = 0.84, 95% CI = 0.32-2.99).

CONCLUSION

Although there were few deaths, our results do not indicate a difference in risk of all-cause mortality among fully vaccinated versus undervaccinated children. Our findings support the safety of the currently recommended immunization schedule with regard to all-cause mortality.

Vaccine shot-limiting: Estimating the prevalence, indicators, and impact on vaccination status - Michigan, 2012

BACKGROUND

Concerns regarding vaccine safety and pain have prompted certain parents to limit the number of shots their child receives per visit. We estimated the prevalence of shot-limited children in Michigan, described their characteristics, assessed whether shot-limited children were up-to-date on recommended vaccinations, and investigated possible intervention points for vaccination education.

METHODS

We analyzed vaccination registry and birth record data of children born in Michigan during 2012 who had ⩾2 vaccination visits, with ⩾1 visits after age 5months. Shot-limited was defined as receiving ⩽2 shots at all visits through age 24months. Nonlimited children received >2 shots at ⩾1 visits. Up-to-date vaccination was based on receipt of a seven-vaccine series and was determined at ages 24months and 35months. Risk ratios (RR) were calculated using risk regression.

RESULTS

Of 101,443 children, a total of 2,967 (3%) children were shot-limited. Mothers of shot-limited children were more likely to be white (RR: 1.2; 95% confidence interval [CI]: 1.2-1.2), college graduate (RR: 1.9; 95% CI: 1.9-2.0), and married (RR: 1.5; 95% CI: 1.5-1.5). Compared with nonlimited children, shot-limited children were more likely to be born in a nonhospital setting (RR: 11.7; 95% CI: 9.4-14.6) and have a midwife attendant (RR: 1.9; 95% CI: 1.7-2.1). Shot-limited children were less likely to be up-to-date on recommended vaccinations (RR: 0.2; 95% CI: 0.2-0.3); this association was stronger for those with a midwife birth attendant (RR: 0.1; 95% CI: 0.1-0.2) rather than a medical doctor (RR: 0.3; 95% CI: 0.2-0.3).

CONCLUSIONS

Shot-limited children are less likely to be up-to-date on vaccinations, possibly leading to increased risk for vaccine-preventable diseases. This association was stronger for those with a midwife birth attendant. This analysis should prompt targeted education, such as to midwives, concerning risks associated with shot-limiting behavior.

HIV, breast cancer and vaccines: what do high-profile cases reveal about stakeholder engagement in research?

Substantially engaging stakeholders in research involves making extensive changes to the full life cycle of research, from the initial stage of selecting research priorities to the final stages of dissemination and implementation. Recent scholarship has explored logistical and methodological challenges, including the time, training and resources required for engagement. However, inadequate attention has been given to the intended ends or goals of engagement - what do we want engagement to achieve? An examination of historical case studies can yield important insights regarding engagement and its intended ends. Using historical perspective methods, we explore how clarity about the ends of engagement can inform the design of engagement efforts and lead to better outcomes. We present several lessons for improving stakeholder-engaged research.

Vaccine Delays, Refusals, and Patient Dismissals: A Survey of Pediatricians

BACKGROUND

Parental noncompliance with the American Academy of Pediatrics and Centers for Disease Control and Prevention immunization schedule is an increasing public health concern. We examined the frequency of requests for vaccine delays and refusals and the impact on US pediatricians' behavior.

METHODS

Using national American Academy of Pediatrics Periodic Surveys from 2006 and 2013, we describe pediatrician perceptions of prevalence of (1) vaccine refusals and delays, (2) parental reasons for refusals and/or delays, and (3) physician dismissals. Questions about vaccine delays were asked only in 2013. We examined the frequency, reasons for, and management of both vaccine refusals and delays by using bivariate and multivariable analyses, which were controlled for practice characteristics, demographics, and survey year.

RESULTS

The proportion of pediatricians reporting parental vaccine refusals increased from 74.5% in 2006 to 87.0% in 2013 (P < .001). Pediatricians perceive that parents are increasingly refusing vaccinations because parents believe they are unnecessary (63.4% in 2006 vs 73.1% in 2013; P = .002). A total of 75.0% of pediatricians reported that parents delay vaccines because of concern about discomfort, and 72.5% indicated that they delay because of concern for immune system burden. In 2006, 6.1% of pediatricians reported "always" dismissing patients for continued vaccine refusal, and by 2013 that percentage increased to 11.7% (P = .004).

CONCLUSIONS

Pediatricians reported increased vaccine refusal between 2006 and 2013. They perceive that vaccine-refusing parents increasingly believe that immunizations are unnecessary. Pediatricians continue to provide vaccine education but are also dismissing patients at higher rates.

Association Between Vaccine Refusal and Vaccine-Preventable Diseases in the United States: A Review of Measles and Pertussis

IMPORTANCE

Parents hesitant to vaccinate their children may delay routine immunizations or seek exemptions from state vaccine mandates. Recent outbreaks of vaccine-preventable diseases in the United States have drawn attention to this phenomenon. Improved understanding of the association between vaccine refusal and the epidemiology of these diseases is needed.

OBJECTIVE

To review the published literature to evaluate the association between vaccine delay, refusal, or exemption and the epidemiology of measles and pertussis, 2 vaccine-preventable diseases with recent US outbreaks.

EVIDENCE REVIEW

Search of PubMed through November 30, 2015, for reports of US measles outbreaks that have occurred since measles was declared eliminated in the United States (after January 1, 2000), endemic and epidemic pertussis since the lowest point in US pertussis incidence (after January 1, 1977), and for studies that assessed disease risk in the context of vaccine delay or exemption.

FINDINGS

We identified 18 published measles studies (9 annual summaries and 9 outbreak reports), which described 1416 measles cases (individual age range, 2 weeks-84 years; 178 cases younger than 12 months) and more than half (56.8%) had no history of measles vaccination. Of the 970 measles cases with detailed vaccination data, 574 cases were unvaccinated despite being vaccine eligible and 405 (70.6%) of these had nonmedical exemptions (eg, exemptions for religious or philosophical reasons, as opposed to medical contraindications; 41.8% of total). Among 32 reports of pertussis outbreaks, which included 10,609 individuals for whom vaccination status was reported (age range, 10 days-87 years), the 5 largest statewide epidemics had substantial proportions (range, 24%-45%) of unvaccinated or undervaccinated individuals. However, several pertussis outbreaks also occurred in highly vaccinated populations, indicating waning immunity. Nine reports (describing 12 outbreaks) provided detailed vaccination data on unimmunized cases; among 8 of these outbreaks from 59% through 93% of unvaccinated individuals were intentionally unvaccinated.

CONCLUSIONS AND RELEVANCE

A substantial proportion of the US measles cases in the era after elimination were intentionally unvaccinated. The phenomenon of vaccine refusal was associated with an increased risk for measles among people who refuse vaccines and among fully vaccinated individuals. Although pertussis resurgence has been attributed to waning immunity and other factors, vaccine refusal was still associated with an increased risk for pertussis in some populations.

Vaccine Hesitancy: Causes, Consequences, and a Call to Action

Vaccine hesitancy reflects concerns about the decision to vaccinate oneself or one's children. There is a broad range of factors contributing to vaccine hesitancy, including the compulsory nature of vaccines, their coincidental temporal relationships to adverse health outcomes, unfamiliarity with vaccine-preventable diseases, and lack of trust in corporations and public health agencies. Although vaccination is a norm in the U.S. and the majority of parents vaccinate their children, many do so amid concerns. The proportion of parents claiming non-medical exemptions to school immunization requirements has been increasing over the past decade. Vaccine refusal has been associated with outbreaks of invasive Haemophilus influenzae type b disease, varicella, pneumococcal disease, measles, and pertussis, resulting in the unnecessary suffering of young children and waste of limited public health resources. Vaccine hesitancy is an extremely important issue that needs to be addressed because effective control of vaccine-preventable diseases generally requires indefinite maintenance of extremely high rates of timely vaccination. The multifactorial and complex causes of vaccine hesitancy require a broad range of approaches on the individual, provider, health system, and national levels. These include standardized measurement tools to quantify and locate clustering of vaccine hesitancy and better understand issues of trust; rapid, independent, and transparent review of an enhanced and appropriately funded vaccine safety system; adequate reimbursement for vaccine risk communication in doctors' offices; and individually tailored messages for parents who have vaccine concerns, especially first-time pregnant women. The potential of vaccines to prevent illness and save lives has never been greater. Yet, that potential is directly dependent on parental acceptance of vaccines, which requires confidence in vaccines, healthcare providers who recommend and administer vaccines, and the systems to make sure vaccines are safe.

The Influence of Provider Communication Behaviors on Parental Vaccine Acceptance and Visit Experience

OBJECTIVES

We investigated how provider vaccine communication behaviors influence parental vaccination acceptance and visit experience.

METHODS

In a cross-sectional observational study, we videotaped provider-parent vaccine discussions (n = 111). We coded visits for the format providers used for initiating the vaccine discussion (participatory vs presumptive), parental verbal resistance to vaccines after provider initiation (yes vs no), and provider pursuit of recommendations in the face of parental resistance (pursuit vs mitigated or no pursuit). Main outcomes were parental verbal acceptance of recommended vaccines at visit's end (all vs ≥ 1 refusal) and parental visit experience (highly vs lower rated).

RESULTS

In multivariable models, participatory (vs presumptive) initiation formats were associated with decreased odds of accepting all vaccines at visit's end (adjusted odds ratio [AOR] = 0.04; 95% confidence interval [CI] = 0.01, 0.15) and increased odds of a highly rated visit experience (AOR = 17.3; 95% CI = 1.5, 200.3).

CONCLUSIONS

In the context of 2 general communication formats used by providers to initiate vaccine discussions, there appears to be an inverse relationship between parental acceptance of vaccines and visit experience. Further exploration of this inverse relationship in longitudinal studies is needed.

Promoting Vaccine Confidence

Vaccine hesitancy incorporates a wide range of parental attitudes and behaviors surrounding vaccines. Ironically, the very success of the immunization program has fueled vaccine concerns; because vaccine-preventable diseases are no longer prevalent, attention has shifted to the safety and necessity of vaccines themselves. This article reviews some of the underlying themes of vaccine hesitancy as well as specific vaccine safety concerns. Strategies for discussing vaccines with concerned parents are also discussed.

Addressing Parental Vaccine Concerns: Engagement, Balance, and Timing

The recent United States measles epidemic has sparked another contentious national discussion about childhood vaccination. A growing number of parents are expressing concerns about the safety of vaccines, often fueled by misinformation from the internet, books, and other nonmedical sources. Many of these concerned parents are choosing to refuse or delay childhood vaccines, placing their children and surrounding communities at risk for serious diseases that are nearly 100% preventable with vaccination. Between 10% and 15% of parents are asking physicians to space out the timing of vaccines, which often poses an ethical dilemma for physicians. This trend reflects a tension between personal liberty and public health, as parents fight to control the decisions that affect the health of their children and public health officials strive to maintain high immunization rates to prevent outbreaks of vaccine-preventable diseases. Interventions to address this emerging public health issue are needed. We describe a framework by which web-based interventions can be used to help parents make evidence-based decisions about childhood vaccinations.

Personal Belief Exemptions to Vaccination in California: A Spatial Analysis

BACKGROUND

School vaccination rates in California have fallen as more parents opt for personal belief exemptions (PBEs) for their children. Our goals were to (1) spatially analyze PBE patterns over time, (2) determine correlates of PBEs, and (3) examine their spatial overlap with personal medical exemptions (PMEs).

METHODS

PBE and PME data for California kindergarten classes from the 2001/2002 to 2013/2014 school years were matched to the locations of schools. Nonspatial clustering algorithms were implemented to group 5147 schools according to their trends in PBE percentages among kindergartners. Cluster assignments were mapped and hotspot analysis was performed to find areas in California where schools sharing trends in PBEs over time were colocated. Schools were further associated both with school-level data on minority enrollment and free and reduced price lunch participation and with charter/private and rural/urban status. Spatial regression was implemented to determine which school-level variables were correlated with PBE rates in the 2013/2014 school year.

RESULTS

Distinct spatial patterns are observed in California when PBE cluster assignments are mapped. Results indicate that schools belonging to the "high PBE" cluster are spatially buffered from those in "low PBE" areas by "medium PBE" schools. Further, PBE rates are positively associated with the percentage of white students, charter status, and private schools.

CONCLUSIONS

Hotspots of high PBE schools are in some cases colocated with schools that have elevated PME rates, prompting concern that herd immunity is diminished for school populations where students have no choice but to remain unvaccinated.

Physician response to parental requests to spread out the recommended vaccine schedule

OBJECTIVES

To assess among US physicians (1) frequency of requests to spread out recommended vaccination schedule for children <2 years, (2) attitudes regarding such requests, and (3) strategies used and perceived effectiveness in response to such requests.

METHODS

An e-mail and mail survey of a nationally representative sample of pediatricians and family physicians from June 2012 through October 2012.

RESULTS

The response rate was 66% (534 of 815). In a typical month, 93% reported some parents of children <2 years requested to spread out vaccines; 21% reported ≥ 10% of parents made this request. Most respondents thought these parents were putting their children at risk for disease (87%) and that it was more painful for children (84%), but if they agreed to requests, it would build trust with families (82%); further, they believed that if they did not agree, families might leave their practice (80%). Forty percent reported this issue had decreased their job satisfaction. Most agreed to spread out vaccines when requested, either often/always (37%) or sometimes (37%); 2% would often/always, 4% would sometimes, and 12% would rarely dismiss families from their practice if they wanted to spread out the primary series. Physicians reported using a variety of strategies in response to requests but did not think they were effective.

CONCLUSIONS

Virtually all providers encounter requests to spread out vaccines in a typical month and, despite concerns, most are agreeing to do so. Providers are using many strategies in response but think few are effective. Evidence-based interventions to increase timely immunization are needed to guide primary care and public health practice.

Frequent vaccination missed opportunities at primary care encounters contribute to underimmunization

OBJECTIVE

To examine missed opportunities to administer an eligible vaccination (MOs) and their contribution to underimmunization in contemporary pediatric practices.

STUDY DESIGN

This study was a retrospective analysis from 42 diverse pediatric practices located throughout the US. Medical records of 50 randomly selected children 3-18 months of age per practice were reviewed in Spring 2013. Immunization status for age and MOs were assessed as of each encounter and as of March 1, 2013.

RESULTS

Of 2076 eligible patients, 72.7% (95% CI 67.6-77.9) were up-to-date with receipt of standard vaccines. Most children (82.4%; 95% CI 78.3-85.9) had at least 1 MO, and 37.8% (95% CI 30.0-46.2) had at least one MO to administer an overdue vaccination. After adjustment, risk of underimmunization was 3.5 times greater for patients who had ever experienced an MO for an overdue vaccination compared with those who had not (adjusted relative risk = 3.5; 95% CI 2.8-4.3). If all age-appropriate vaccinations had been administered at the last recorded encounter, 45.5% (95% CI 36.8-54.5) of the underimmunized patients would have been up to date at the time of assessment.

CONCLUSION

MOs were common and contributed substantially to underimmunization in this contemporary sample of diverse primary care practice settings.

Geographic clusters in underimmunization and vaccine refusal

BACKGROUND AND OBJECTIVE

Parental refusal and delay of childhood vaccines has increased in recent years and is believed to cluster in some communities. Such clusters could pose public health risks and barriers to achieving immunization quality benchmarks. Our aims were to (1) describe geographic clusters of underimmunization and vaccine refusal, (2) compare clusters of underimmunization with different vaccines, and (3) evaluate whether vaccine refusal clusters may pose barriers to achieving high immunization rates.

METHODS

We analyzed electronic health records among children born between 2000 and 2011 with membership in Kaiser Permanente Northern California. The study population included 154,424 children in 13 counties with continuous membership from birth to 36 months of age. We used spatial scan statistics to identify clusters of underimmunization (having missed 1 or more vaccines by 36 months of age) and vaccine refusal (based on International Classification of Diseases, Ninth Revision, Clinical Modification codes).

RESULTS

We identified 5 statistically significant clusters of underimmunization among children who turned 36 months old during 2010-2012. The underimmunization rate within clusters ranged from 18% to 23%, and the rate outside them was 11%. Children in the most statistically significant cluster had 1.58 (P < .001) times the rate of underimmunization as others. Underimmunization with measles, mumps, rubella vaccine and varicella vaccines clustered in similar geographic areas. Vaccine refusal also clustered, with rates of 5.5% to 13.5% within clusters, compared with 2.6% outside them.

CONCLUSIONS

Underimmunization and vaccine refusal cluster geographically. Spatial scan statistics may be a useful tool to identify locations with challenges to achieving high immunization rates, which deserve focused intervention.

Nonmedical exemptions from school immunization requirements: a systematic review

We summarized studies describing the prevalence of, trends in, and correlates of nonmedical exemptions from school vaccination mandates and the association of these policies with the incidence of vaccine-preventable disease. We searched 4 electronic databases for empirical studies published from 1997 to 2013 to capture exemption dynamics and qualitatively abstracted and synthesized the results. Findings from 42 studies suggest that exemption rates are increasing and occur in clusters; most exemptors questioned vaccine safety, although some exempted out of convenience. Easier state-level exemption procedures increase exemption rates and both individual and community disease risk. State laws influence exemption rates, but policy implementation, exemptors' vaccination status, and underlying mechanisms of geographical clustering need to be examined further to tailor specific interventions.

Timely versus delayed early childhood vaccination and seizures

BACKGROUND

Little is known regarding the timing of childhood vaccination and postvaccination seizures.

METHODS

In a cohort of 323 247 US children from the Vaccine Safety Datalink born from 2004 to 2008, we analyzed the association between the timing of childhood vaccination and the first occurrence of seizure with a self-controlled case series analysis of the first doses of individual vaccines received in the first 2 years of life.

RESULTS

In infants, there was no association between the timing of infant vaccination and postvaccination seizures. In the second year of life, the incident rate ratio (IRR) for seizures after receipt of the first measles-mumps-rubella vaccine (MMR) dose at 12 to 15 months was 2.65 (95% confidence interval [CI] 1.99-3.55); the IRR after an MMR dose at 16 to 23 months was 6.53 (95% CI 3.15-13.53). The IRR for seizures after receipt of the first measles-mumps-rubella-varicella vaccine (MMRV) dose at 12 to 15 months was 4.95 (95% CI 3.68-6.66); the IRR after an MMRV dose at 16 to 23 months was 9.80 (95% CI 4.35 -22.06).

CONCLUSIONS

There is no increased risk of postvaccination seizure in infants regardless of timing of vaccination. In year 2, delaying MMR vaccine past 15 months of age results in a higher risk of seizures. The strength of the association is doubled with MMRV vaccine. These findings suggest that on-time vaccination is as safe with regard to seizures as delayed vaccination in the first year of life, and that delayed vaccination in the second year of life is associated with more postvaccination seizures than on-time vaccination.

Epidemiology of vaccine hesitancy in the United States

Vaccines are among the most effective public health interventions against infectious diseases. However, there is evidence in the United States for parents either delaying or refusing recommended childhood vaccination. Exemptions to school immunization laws and use of alternative schedule from those recommended by the Advisory Committee on Immunization Practices and the American Academy of Pediatrics cannot only increase the risk of children contracting vaccine-preventable diseases but also increases the risk of infecting others who are either too young to be vaccinated, cannot be vaccinated for medical reasons or did not develop a sufficient immunological response to the vaccine. Healthcare providers are cited as the most influential source by parents on vaccine decision-making. Vaccine hesitancy needs to be addressed by healthcare providers and the scientific community by listening to the parental concerns and discussing risks associated with either delaying or refusing vaccines.

Vaccination coverage levels among children enrolled in the Vaccine Safety Datalink

INTRODUCTION

The Vaccine Safety Datalink (VSD) is a collaborative project whose infrastructure provides comprehensive medical and immunization histories for more than 9 million adults and children annually, a predominantly insured population. This study provides the coverage rates of recommended vaccines among children 19-35 months in the VSD from 2005 through 2010. We examine the consistency in vaccine coverage levels, detect possible trends, and evaluate any effect of vaccine shortages on coverage in the VSD.

METHODS

We included data from all 10 VSD sites, and examined each year independently. Coverage rates were defined as the percentage of children in the VSD aged 19, 24, or 35 months in a given study year who had received the specified Advisory Committee on Immunization Practices (ACIP) recommended vaccine(s).

RESULTS

We assessed coverage on 658,154 children. The overall coverage rate for children receiving all of the specified ACIP recommended vaccines was 73%, 80%, and 78% at ages 19, 24, and 35 months respectively. The range of coverage across all ages and years was 95-97% for polio vaccine, 91-97%, for MMR vaccine, 94-97% for HepB vaccine, 81-95% for DTaP vaccine, 90-95% for varicella vaccine, 66-91% for PCV, and 93-98% for Hib vaccine. Coverage rates of 4 or more doses of PCV were relatively low in 2005 possibly due to a vaccine shortage, and increased sharply in 2007. Hib vaccine coverage was relatively stable among all ages until 2009 when rates declined among children aged 19 and 24 months also during a vaccine shortage.

CONCLUSIONS

Vaccine coverage in the VSD is high, but there is a decline from 2005 to 2010. The results of this study provide benchmark data for future studies, and describe how vaccine supply shortages and resulting changes in ACIP recommendations may have affected vaccine coverage rates in the VSD.

Pneumococcal meningitis in children: epidemiology, serotypes, and outcomes from 1997-2010 in Utah

BACKGROUND

After licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States in 2000, the incidence of pediatric pneumococcal meningitis decreased significantly. However, cases continue to occur. It is unknown whether meningitis due to PCV7 and non-PCV7 serotypes causes similar morbidity and mortality.

METHODS

We performed a retrospective cohort study of laboratory-confirmed pneumococcal meningitis among Utah children from 1997 to 2010. We reviewed medical records and obtained clinical data during the acute illness and follow-up data on neurologic sequelae.

RESULTS

Sixty-eight cases of meningitis were identified. PCV7 serotypes caused 64% of cases before and 25% of cases after licensure of PCV7 (P < .01). The age range was similar before and after PCV7 licensure (P = .5). The overall case fatality rate was 13% and was similar among cases caused by PCV7 and non-PCV7 serotypes (P = .7). Children with PCV7 serotypes were more likely to require mechanical ventilation (68% vs 34%; P < .01). Of all survivors, 63% had neurologic sequelae, and the proportion was similar after infection with PCV7 or non-PCV7 serotypes (P = .1). More than one-half (54%) of all children who developed pneumococcal meningitis in the PCV7 period were eligible for PCV7 and had not been immunized.

CONCLUSIONS

Pneumococcal meningitis continues to be associated with high mortality and morbidity; death and neurologic sequelae are common with both PCV7 and non-PCV7 serotype meningitis. The substantial burden of this disease and continued cases among unimmunized children reinforce the need for more effective immunization strategies and continued surveillance in the era of PCV13.

A randomized trial to increase acceptance of childhood vaccines by vaccine-hesitant parents: a pilot study

OBJECTIVE

A cluster randomized trial was performed to evaluate an educational intervention to improve parental attitudes and vaccine uptake in vaccine-hesitant parents.

METHODS

Two primary care sites were randomized to provide families with either usual care or an intervention (video and written information) for vaccine-hesitant parents. Eligible parents included those presenting for their child's 2-week well-child visit with performance on the Parent Attitudes about Childhood Vaccines (PACV) survey suggesting vaccine hesitancy (score ≥25). Enrollees completed PACV surveys at the 2-month well-child visit and vaccination status at 12 weeks of age was assessed. The primary outcome was the difference in PACV scores obtained at enrollment and 2 months between the 2 groups. The proportion of on-time vaccination was also compared at 12 weeks.

RESULTS

A total of 454 parents were approached, and 369 (81.3%) participated; 132 had PACV scores of ≥25 and were enrolled, 67 in the control group (mean PACV score 37) and 55 in the intervention group (mean PACV score 40). Two-month PACV surveys were completed by 108 (∼90%) of enrollees. Parents in the intervention group had a significant decrease in PACV score at 2 months compared to control (median difference 6.7, P = .049); this remained significant after adjustment for baseline PACV score, race/ethnicity, and income (P = .044). There was no difference in the on-time receipt of vaccines between groups at 12 weeks.

CONCLUSIONS

A brief educational intervention for vaccine-hesitant parents was associated with a modest but significant increase in measured parental attitudes toward vaccines.