Population Attributable Fraction of Nonvaccination of Child and Adolescent Vaccines Attributed to Parental Vaccine Hesitancy, 2018-2019

Parental hesitancy about COVID-19, influenza, HPV, and other childhood vaccines

BACKGROUND

Some public health professionals have expressed concern that the COVID-19 pandemic has increased vaccine hesitancy about routine childhood vaccines; however, the differential prevalence of vaccine hesitancy about specific vaccines has not been measured.

METHODS

Data from the National Immunization Survey-Child COVID-19 Module (NIS-CCM) were analyzed to assess the proportion of children ages 6 months-17 years who have a parent with hesitancy about: COVID-19, influenza, human papillomavirus (HPV) (for children ≥ 9 years) vaccines, and "all other childhood shots." Interviews from October 2022 through April 2023 were analyzed.

RESULTS

The percentage of children with a vaccine-hesitant parent varied by vaccine. 55.9% of children had a parent hesitant about COVID-19 vaccine, 30.9% hesitant about influenza vaccine, 30.1% hesitant about HPV vaccine, and 12.2% had a parent hesitant about other vaccines such as measles, polio, and tetanus.

CONCLUSION

The study findings suggest that differential interventions and communications to parents be used to educate about COVID-19, influenza, HPV, and routine childhood vaccinations because the hesitancy levels differ widely.

Pediatric HPV vaccination: Provider recommendations matter among hesitant parents

INTRODUCTION

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. HPV-associated diseases are preventable with vaccination, but HPV vaccine coverage remains below other vaccines recommended during childhood and adolescence. We examined correlates of pediatric HPV vaccination among parents who have reported hesitancy toward the HPV vaccine. In addition to sociodemographic correlates, we investigated the relationships between the social process of healthcare provider recommendations and pediatric HPV vaccination.

METHODS

We utilized phone survey data (N = 2201) collected in October 2022 via random digit dialing of Arkansan adults-Black and Hispanic respondents were oversampled for adequate representation. The survey was provided in English and Spanish. The analysis focused on a subsample of parents of children ages 9 to 17 years who reported HPV vaccine hesitancy (n = 201). Analyses include descriptive statistics, bivariate logistic regression, and multivariate logistic regression with Full Information Maximum Likelihood estimation.

RESULTS

A third (32.96%) of vaccine-hesitant parents reported their child(ren) had received at least one dose of the HPV vaccine. Only half (50.93%) of vaccine-hesitant parents received a healthcare provider recommendation to vaccinate their child(ren) between the ages of 9 and 17 against HPV. Adjusted odds of pediatric HPV vaccination were four times greater when vaccine-hesitant parents received a healthcare provider's recommendation (OR = 4.67; 95% CI[1.89, 11.55]) compared to when they had not. Pediatric HPV vaccination for parents whose provider did not recommend the HPV vaccine was not significantly different from those with no provider.

CONCLUSION

Healthcare provider recommendations are important for promoting HPV vaccination even among parents who are vaccine hesitant. Additional research is needed to understand why pediatric HPV vaccine recommendations are not made more often or consistently, particularly among vaccine-hesitant populations. This study demonstrates support for the growing body of research on hesitant adopters.

Hesitant but vaccinated: Lessons learned from hesitant adopters

INTRODUCTION

The WHO SAGE vaccine hesitancy working group defined vaccine hesitancy as the delay or refusal of vaccination. Questions about individuals who become vaccinated while hesitant, or remain unvaccinated even though they are not hesitant, are unimaginable when starting from this behaviorally related definition of vaccine hesitancy. More critically, behaviorally related definitions limit the possibilities for vaccine hesitancy research to be translatable into clinical and public health practices that can increase vaccination.

LESSONS LEARNED

Emerging research on hesitant adopters provides several lessons for the conceptualization of vaccine hesitancy and how practitioners might increase vaccination. Conceptualizations of vaccine hesitancy must account for some of the big lessons we have learned from hesitant adopters: (1) vaccine hesitancy and vaccination co-occur for many; (2) vaccine hesitancy may not always be characterized by a punctuated point-in-time or moment; and (3) following from the second lesson, vaccine hesitancy may not be temporally bound to the moments preceding a vaccination decision.

CONCLUSIONS

We recommend conceptualizing vaccine-hesitant attitudes as distinctive from behaviors, and not temporally bound to moments preceding vaccination decisions. Sharpening the use of vaccine hesitancy and its temporal characteristics could benefit from engagement with the Life Course Paradigm. We recommend healthcare professionals provide a recommendation even when individuals express hesitancy. Finally, we recommend public health officials consider ways to improve the frequency and consistency of provider recommendations even among patients who are hesitant.

Changes in vaccine hesitancy among parents of children aged 6 months - 17 Years, National Immunization Surveys, 2019-2022

BACKGROUND

Vaccine hesitancy (VH) has been a major contributor to large outbreaks of vaccine-preventable diseases globally, including in the United States.

METHODS

Data from the 2019-2022 National Immunization Surveys were analyzed to assess parental hesitancy toward routine vaccination of their children aged 6 months -17 years. Joinpoint regression was employed to investigate trends in VH from 2019 to 2022 nationally overall and among socio-demographic subgroups. Using logistic regression, the difference between the prevalence of VH before and after the authorization of the COVID-19 vaccine for children aged 6 months-4 years, 5-11 years, and 12-17 years was computed. Both unadjusted and adjusted estimates were reported. VH was also compared within each socio-demographic subgroup with a reference level, at two-time points- before and after the authorization of the COVID-19 vaccine for each age group.

RESULTS

Overall, VH remained around 19.0 % from Q2 2019 to Q3 2022. Parents of non-Hispanic Black children had the largest average quarterly decrease in VH (β = -0.55; p < 0.05 by test for trend). After the authorization of the COVID-19 vaccine for children aged 6 months to 4 years, the adjusted percentage of children having parents that reported VH decreased by 2.2 (95 % CI: -3.9, -0.6) percentage points (pp) from 21.6 % to 19.4 %. Conversely, for children aged 5-11 years, VH increased by 1.2 (95 % CI: 0.2, 2.3) pp, from 19.8 % to 21.0 %. VH among parents of non-Hispanic Black children decreased after the authorization of the COVID-19 vaccine for adolescents aged 12-17 years but remained significantly higher compared to parents of non-Hispanic White children before and after authorization of the COVID-19 vaccine for all age groups.

DISCUSSION

About 1 in 5 children had parents reporting VH from 2019 to 2022. Parental VH increased after the authorization of the COVID-19 vaccine for children aged 5-11 years and declined for children aged 6 months-4 years.

Vaccination patterns and up-to-date status of children 19-35 months, 2011-2021

INTRODUCTION

Being up-to-date with all recommended vaccines is needed to protect children from vaccine preventable diseases. Understanding vaccination patterns is needed to develop messaging and strategies to increase vaccination uptake and confidence.

METHODS

Data from the 2011 to 2021 National Immunization Surveys was used to assess trends and disparities in vaccination patterns, zero vaccination status, and up-to-date status of U.S. children by 19-35 months.

RESULTS

From 2011 to 2021, adherence to the recommended schedule using the stringent definition increased from 35.7 % to 52.2 % (p < 0.01), adherence to the alternate schedule decreased from 28.2 % to 15.1 % (p < 0.01), and proportion of children who were not up-to-date decreased from 49.0 % to 33.3 % (p < 0.01). However, the proportion of children who had zero vaccinations did not change from 2011 (0.9 %) to 2021 (0.9 %; p = 0.08). In 2021, children 19-23 months were less likely to follow the recommended schedule than children 24-29 months (49.2 % compared to 56.4 %, p < 0.01). Adherence to the recommended schedule among children 19-23 months decreased in 2021 compared to 2020 overall and for some subpopulations (e.g. those with non-Hispanic (NH) Black parents (33.2 % compared to 44.9 %, p < 0.01). Furthermore, it was lowest among children of NH Black parents living at or below the federal poverty level (31.2 %) compared to their respective NH White counterparts (43.6 %, p < 0.01).

CONCLUSIONS

While there were overall increases in adherence to the recommended schedule from 2011 to 2021, a sustained catch-up program is needed to prevent missed vaccinations and achieve equitable vaccination coverage for all children.

Parental vaccine hesitancy and acceptance of a COVID-19 vaccine: An internet-based survey in the US and five Asian countries

COVID-19 vaccination rates for children globally are relatively low. This study aimed to investigate parental vaccine hesitancy and parents' acceptance of a COVID-19 for their children for their children in the United States, China, Taiwan, India, Indonesia, and Malaysia.We analyzed data from an opt-in, internet-based cross-sectional study (n = 23,940). Parents were asked about their acceptance of a COVID-19 vaccine for their children, and if they would accept the vaccine with different risk and effectiveness profiles for themselves. Poisson regression was used to generate prevalence ratios (PR) of the relationship between vaccine acceptance for a child and vaccine profile, by country and waves and overall. Between August 2020 and June 2021, COVID-19 vaccine acceptance for children decreased in the United States (89% to 72%) and Taiwan (79% to 71%), increased in India (91% to 96%) and Malaysia (81% to 91%), and was stable in Indonesia (86%) and China (at 87%-90%). Vaccine risk and effectiveness profiles did not consistently affect parent's acceptance of a COVID-19 vaccine for their children. Instead, being not hesitant was a large driver of vaccine acceptance (PR: 1.24, 95% CI: 1.14, 1.36). Adolescent COVID-19 vaccination have already been established in many high and middle-income countries, but our study suggests that there is a movement of vaccine hesitancy which could impede the success of future pediatric and adolescent COVID-19 vaccination programs.

Population Attributable Fraction of Nonvaccination of COVID-19 Due to Vaccine Hesitancy, United States, 2021

Understanding the extent of coronavirus disease 2019 (COVID-19) nonvaccination attributable to vaccine hesitancy versus other barriers can help prioritize approaches for increasing vaccination uptake. Using data from the Centers for Disease Control and Prevention's Research and Development Survey, a nationally representative survey fielded from May 1 to June 30, 2021 (n = 5,458), we examined the adjusted population attribution fraction (PAF) of COVID-19 vaccine hesitancy attributed to nonvaccination according to sociodemographic characteristics and health-related variables. Overall, the adjusted PAF of nonvaccination attributed to vaccine hesitancy was 76.1%. The PAF was highest among adults who were ≥50 years of age (87.9%), were non-Hispanic White (83.7%), had a bachelor's degree or higher (82.7%), had an annual household income of at least $75,000 (85.5%), were insured (82.4%), and had a usual place for health care (80.7%). The PAF was lower for those who were current smokers (65.3%) compared with never smokers (77.9%), those who had anxiety or depression (65.2%) compared with those who did not (80.1%), and those who had a disability (64.5%) compared with those who did not (79.2%). Disparities in PAF suggest areas for prioritization of efforts for intervention and development of messaging campaigns that address all barriers to uptake, including hesitancy and access, to advance health equity and protect individuals from COVID-19.

Routine childhood immunization in Sub-Saharan Africa: addressing parental vaccine hesitancy

OBJECTIVES

Parental vaccine hesitancy (VH) is a major barrier to childhood vaccination. We aimed to identify the determinants of parental VH towards routine childhood immunization in 12 Sub-Saharan African countries.

STUDY DESIGN

A cross-sectional study was conducted from November 1 to December 15, 2022.

METHODS

Parents of children aged 19 months to 6 years and residing in the Sub-Saharan Africa were included. An anonymous online survey and face-to-face interviews were conducted. The Parent Attitude about Childhood Vaccine Scale was used to identify vaccine-hesitant parents. Multivariate regression and mediating analysis were performed.

RESULTS

Across the 5032 participants, 21.2% were hesitant towards routine childhood immunization. Urban residents (adjusted odds ratio [AOR] = 1.32, 95% confidence interval [CI]: 1.10-1.58), non-first-born children (AOR = 1.54, 95% CI: 1.19-1.98), and chronically ill children (AOR = 2.00, 95% CI: 1.69-2.37) increased the likelihood of parental VH. Mothers with higher education, attending at least one antenatal care (ANC) visit (AOR = 0.25, 95% CI: 0.19-0.32), and had a healthcare facility-based delivery (AOR = 0.55, 95% CI: 0.44-0.70) decreased the odds of parental VH. Parental VH mediated the effect of ANC and mothers' age on vaccination uptake. ANC increased the odds of vaccination uptake (odds ratio [OR] = 12.49, 95% CI: 9.68-16.13). Parental VH mediated the association between ANC and vaccination uptake, decreasing the likelihood of vaccination uptake (OR = 0.12, 95% CI: 0.10-0.14). Each additional year of the mother's age decreased the odds of vaccination uptake (OR = 0.95, 95% CI: 0.95-0.96). The indirect effect of mother's age on vaccination through parental VH decreased the odds of vaccination uptake (OR = 0.45, 95% CI: 0.44-0.45). Parental VH continued to be a mediator of the combined effect of mother's age and ANC on vaccination uptake, decreasing the likelihood of vaccination uptake (OR = 0.0017, 95% CI: 0.00166-0.00168).

CONCLUSIONS

Context-specific interventions are needed to address parental VH and improve vaccine acceptance and coverage.

Hepatitis B eradication: vaccine as a key player

OBJECTIVE

Despite the availability of a highly effective and safe vaccine against hepatitis B virus (HBV) infection for 40 years, still almost 300 million persons are estimated to be chronically infected by this virus worldwide. The World Health Organization (WHO) has proposed a plan for hepatitis elimination by 2030. However, several factors, such as the reduction and limitation in vaccination campaigns or vaccine hesitancy (VH) in some regions of the World, might have played a role in limiting the worldwide coverage of hepatitis B prophylaxis. This review aims to describe which factors, such as VH, may be hampering the WHO 2030 goal for hepatitis B eradication.

METHODS

The review describes the development and characteristics of the HBV vaccine, from the first plasma-derived to the recombinant one. Eventual limitations in its effectiveness and particularly VH were reviewed.

RESULTS

The apparent pitfalls of the HBV vaccine, such as long-term effectiveness, vaccine-escape mutants, and adverse effects, were proven not to be a concern for this vaccine. However, VH persists and was even intensified by the COVID-19 pandemic.

CONCLUSIONS

Many barriers still exist, such as vaccine availability, lack of awareness of the benefits of HBV vaccination, and VH. HBV VH seems to be eventually overcome in many settings with active education campaigns and information, stressing the importance of developing these strategies to achieve the 2030 goal of the WHO.

Prevalence of influenza-specific vaccination hesitancy among adults in the United States, 2018

BACKGROUND

The role of vaccine hesitancy on influenza vaccination is not clearly understood. Low influenza vaccination coverage in U.S. adults suggests that a multitude of factors may be responsible for under-vaccination or non-vaccination including vaccine hesitancy. Understanding the role of influenza vaccination hesitancy is important for targeted messaging and intervention to increase influenza vaccine confidence and uptake. The objective of this study was to quantify the prevalence of adult influenza vaccination hesitancy (IVH) and examine association of IVH beliefs with sociodemographic factors and early-season influenza vaccination.

METHODS

A four-question validated IVH module was included in the 2018 National Internet Flu Survey. Weighted proportions and multivariable logistic regression models were used to identify correlates of IVH beliefs.

RESULTS

Overall, 36.9% of adults were hesitant to receive an influenza vaccination; 18.6% expressed concerns about vaccination side effects; 14.8% personally knew someone with serious side effects; and 35.6% reported that their healthcare provider was not the most trusted source of information about influenza vaccinations. Influenza vaccination ranged from 15.3 to 45.2 percentage points lower among adults self-reporting any of the four IVH beliefs. Being female, age 18-49 years, non-Hispanic Black, having high school or lower education, being employed, and not having primary care medical home were associated with hesitancy.

CONCLUSIONS

Among the four IVH beliefs studied, being hesitant to receiving influenza vaccination followed by mistrust of healthcare providers were identified as the most influential hesitancy beliefs. Two in five adults in the United States were hesitant to receive an influenza vaccination, and hesitancy was negatively associated with vaccination. This information may assist with targeted interventions, personalized to the individual, to reduce hesitancy and thus improve influenza vaccination acceptance.

Knowledge on Parental Hesitancy toward COVID-19 Vaccination of Children 5–11 Years Old

Although vaccines are the safest and the most effective measure to prevent disease, disability, and death from various pediatric infectious diseases, parental vaccine hesitancy is a common and increasing phenomenon worldwide. To contribute to improving our knowledge on parental willingness and hesitancy toward COVID-19 vaccine administration in children aged 5–11 years, an anonymous online questionnaire was disseminated in Italy after the COVID-19 vaccine’s authorization for this age group. An online survey was conducted using the Crowd Signal platform from 15 December 2021 to 15 January 2022 in Italy among parents of children 5–11 years old. A total of 3433 questionnaires were analyzed. Overall, a “Favorable” position was observed in 1459 (42.5%) parents, a “Doubtful” one in 1223 (35.6%) and a “Hesitant/Reluctant” one in 751 (21.9%). The univariate multinomial logistic regression analysis and the multivariate multinomial logistic regression analysis showed that the Hesitant/Reluctant parents were younger than 40 years of age, mostly female, with a secondary or middle school degree, an annual income below EUR 28,000, more than one child in the age range from 5 to 11 years, an underestimated consideration of the severity of COVID-19’s effects, and concern regarding the COVID-19 vaccines in general. These results show that in Italy, most parents of children aged 5 to 11 were doubtful or hesitant/reluctant to vaccinate their children against the COVID-19 virus. Poor trust in health institutions as well as poor consideration of the epidemiological and clinical relevance of COVID-19 in children seem to have played the biggest roles in forming these attitudes. Moreover, the negative attitude of several parents who previously agreed to immunize their children against other childhood illnesses according to the official national pediatric immunization schedule clearly indicates that only the COVID-19 vaccine was put in doubt or rejected. All these findings lead us to conclude that to improve COVID-19 vaccination coverage in children aged 5 to 11, health authorities should increase parental education on the true clinical relevance of COVID-19 and on the importance of its prevention to hinder the evolution of the pandemic in pediatric subjects and the emergence of new variants, and its relative weight in influencing the efficacy of vaccines.

Vaccination Coverage by Age 24 Months Among Children Born During 2018-2019 - National Immunization Survey-Child, United States, 2019-2021

Millions of young children are vaccinated safely in the United States each year against a variety of potentially dangerous infectious diseases (1). The Advisory Committee on Immunization Practices (ACIP) recommends routine vaccination against 14 diseases during the first 24 months of life* (2). This report describes vaccination coverage by age 24 months using data from the National Immunization Survey-Child (NIS-Child).^† Compared with coverage among children born during 2016-2017, coverage among children born during 2018-2019 increased for a majority of recommended vaccines. Coverage was >90% for ≥3 doses of poliovirus vaccine (93.4%), ≥3 doses of hepatitis B vaccine (HepB) (92.7%), ≥1 dose of measles, mumps, and rubella vaccine (MMR) (91.6%), and ≥1 dose of varicella vaccine (VAR) (91.1%); coverage was lowest for ≥2 doses of hepatitis A vaccine (HepA) (47.3%). Vaccination coverage overall was similar or higher among children reaching age 24 months during March 2020 or later (during the COVID-19 pandemic) than among those reaching age 24 months before March 2020 (prepandemic); however, coverage with the combined 7-vaccine series^§ among children living below the federal poverty level or in rural areas decreased by 4-5 percentage points during the pandemic (3). Among children born during 2018-2019, coverage disparities were observed by race and ethnicity, poverty status, health insurance status, and Metropolitan Statistical Area (MSA) residence. Coverage was typically higher among privately insured children than among children with other insurance or no insurance. Persistent disparities by health insurance status indicate the need to improve access to vaccines through the Vaccines for Children (VFC) program.^¶ Providers should review children's histories and recommend needed vaccinations during every clinical encounter and address parental hesitancy to help reduce disparities and ensure that all children are protected from vaccine-preventable diseases.

Trends in vaccination schedules and up-to-date status of children 19-35 months, United States, 2015-2020

OBJECTIVES

To estimate trends in, and factors associated with, vaccination patterns and up-to-date immunization status of U.S. children by 19 to 35 months of age.

METHODS

Data from the 2015 to 2020 National Immunization Surveys were used to assess trends in vaccination patterns, up-to-date status, and zero vaccination status of U.S. children by 19-35 months. Vaccination patterns were categorized as: 1) recommended, 2) alternate, or 3) unknown or unclassifiable. Multivariable analyses were conducted to examine factors associated with each vaccination pattern and up-to-date status for all recommended vaccines.

RESULTS

From 2015 to 2020, the proportion of U.S. children completing the recommended schedule increased from 62.5% to 69.4%, alternative schedule decreased from 21.6% to 16.2%, and unknown or unclassifiable schedules decreased from 15.9% to 14.3%. In addition, being not up-to-date decreased from 39.7% to 35.6%. There was no change in the percentage of children receiving zero vaccinations from 2015 to 2020 (0.9% to 0.9%). Respondents with lower household income or who were uninsured were more likely to follow an alternate or unknown/unclassifiable schedule, or not be up-to-date with vaccines.

CONCLUSION

Following any schedule other than the recommended schedule was associated with not being up-to-date on immunizations. Increased efforts to catch up on recommended vaccines is important for protecting children's health. Further efforts should be made to improve timely adherence to recommended vaccination schedules, particularly among populations with the largest disparities in coverage through a tailored approach to increase confidence in and access to vaccines.

Invited Commentary: The Use of Population Attributable Fractions in Studies of Vaccine Hesitancy

Vaccine hesitancy-the delay or refusal of vaccines despite their availability-has been linked to lower vaccination rates and outbreaks of vaccine-preventable diseases. Using cross-sectional surveys of 78,725 parents and other family members in the United States, Nguyen et al. (Am J Epidemiol. 2022;191(9):1626-1635) calculated the population attributable fraction (PAF) of vaccine hesitancy on nonreceipt of recommended childhood vaccines, including influenza vaccine. The PAF is readily calculated: p(rr - 1)/rr, where p is the proportion of those hesitant among nonvaccinated individuals, and rr is the risk ratio of nonvaccination between those hesitant over those nonhesitant. By vaccine, the PAF ranged from 6.5% for nonreceipt of the hepatitis B vaccine birth dose to 31.3% for nonreceipt of the diphtheria-tetanus-pertussis vaccine dose 3. For nonreceipt of influenza vaccine, the PAF varied geographically, with relatively high values in some Northeast (e.g., New York at 22.6%) and Northwest (e.g., Oregon at 23.0%) states and lower values in certain Southern (e.g., Louisiana at 7.5%) and Mountain West (e.g., Utah at 8.8%) states. The PAF can elucidate the contribution of vaccine hesitancy on nonvaccination in different circumstances. Future studies can apply this technique in different populations and incorporate different measures of vaccine hesitancy.