Vaccination coverage among American Indian and Alaska native children, 2006-2010

Social Determinants of COVID-19 Vaccination Rates: A Time-Constrained Multiple Mediation Analysis

Objective To estimate the multiple direct/indirect effects of social, environmental, and economic factors on COVID-19 vaccination rates (series complete) in the 3109 continental counties in the United States (U.S.). Study design  The dependent variable was the COVID-19 vaccination rates in the U.S. (April 15, 2022). Independent variables were collected from reliable secondary data sources, including the Census and CDC. Independent variables measured at two different time frames were utilized to predict vaccination rates. The number of vaccination sites in a given county was calculated using the geographic information system (GIS) packages as of April 9, 2022. The Internet Archive (Way Back Machine) was used to look up data for historical dates. Methods  A chain of temporally-constrained least absolute shrinkage and selection operator (LASSO) regressions was used to identify direct and indirect effects on vaccination rates. The first regression identified direct predictors of vaccination rates. Next, the direct predictors were set as response variables in subsequent regressions and regressed on variables that occurred before them. These regressions identified additional indirect predictors of vaccination. Finally, both direct and indirect variables were included in a network model. Results  Fifteen variables directly predicted vaccination rates and explained 43% of the variation in vaccination rates in April 2022. In addition, 11 variables indirectly affected vaccination rates, and their influence on vaccination was mediated by direct factors. For example, children in poverty rate mediated the effect of (a) median household income, (b) children in single-parent homes, and (c) income inequality. For another example, median household income mediated the effect of (a) the percentage of residents under the age of 18, (b) the percentage of residents who are Asian, (c) home ownership, and (d) traffic volume in the prior year. Our findings describe not only the direct but also the indirect effect of variables. Conclusions  A diverse set of demographics, social determinants, public health status, and provider characteristics predicted vaccination rates. Vaccination rates change systematically and are affected by the demographic composition and social determinants of illness within the county. One of the merits of our study is that it shows how the direct predictors of vaccination rates could be mediators of the effects of other variables.

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

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

Disparities in Outcomes During Lower Respiratory Tract Infection in American Indian Children: A 9-Year Retrospective Analysis in a Rural Population in South Dakota

BACKGROUND

American Indian (AI) children are at increased risk for severe disease during lower respiratory tract infection (LRTI). The reasons for this increased severity are poorly understood. The objective of this study was to define the clinical presentations of LRTI and highlight the differences between AI and non-AI previously healthy patients under the age of 24 months.

METHODS

We performed a retrospective chart review between October 2010 and December 2019. We reviewed 1245 patient charts and 691 children met inclusion criteria for this study. Data records included demographics, clinical, laboratory data, and illness outcomes.

RESULTS

Of 691 patients, 120 were AI and 571 were non-AI. There was a significant difference in breast-feeding history (10% of AI vs. 28% of non-AI, P < 0.0001) and in secondhand smoke exposure (37% of AI vs. 21% of non-AI, P < 0.0001). AI children had increased length of hospitalization compared with non-AI children (median of 3 vs. 2 days, P < 0.001). In addition, AI children had higher rates of pediatric intensive unit admission (30%, n = 37) compared with non-AI children (11%; n = 67, P < 0.01). AI children also had higher rates (62.5%, n = 75) and duration of oxygen supplementation (median 3 days) than non-AI children (48%, n = 274, P = 0.004; median 2 days, P = 0.0002). On a multivariate analysis, AI race was an independent predictor of severe disease during LRTI.

CONCLUSIONS

AI children have increased disease severity during LRTI with longer duration of hospitalization and oxygen supplementation, a higher rate of oxygen requirement and Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation pediatric intensive care unit admissions, and a greater need for mechanical ventilation. These results emphasize the need for improvement in health policies and access to health care in this vulnerable population.

The 1925 Diphtheria Antitoxin Run to Nome - Alaska: A Public Health Illustration of Human-Animal Collaboration

Diphtheria is an acute toxin-mediated superficial infection of the respiratory tract or skin caused by the aerobic gram-positive bacillus Corynebacterium diphtheriae. The epidemiology of infection and clinical manifestations of the disease vary in different parts of the world. Historical accounts of diphtheria epidemics have been described in many parts of the world since antiquity. Developed in the late 19th century, the diphtheria antitoxin (DAT) played a pivotal role in the history of public health and vaccinology prior to the advent of the diphtheria-tetanus toxoids and acellular pertussis (DTaP) vaccine. One of the most significant demonstrations of the importance of DAT was its use in the 1925 diphtheria epidemic of Nome, Alaska. Coordinated emergency delivery of this life-saving antitoxin by dog-sled relay in the harshest of conditions has left a profound legacy in the annals of vaccinology and public health. Lead dogs Balto and Togo, and the dog-led antitoxin run of 1925 represent a dynamic illustration of the contribution made by non-human species towards mass immunization in the history of vaccinology. This unique example of cooperative interspecies fellowship and collaboration highlights the importance of the human-animal bond in the one-health initiative.

Vaccination Coverage Disparities Between Foreign-Born and U.S.-Born Children Aged 19-35 Months, United States, 2010-2012

Healthy People 2020 targets high vaccination coverage among children. Although reductions in coverage disparities by race/ethnicity have been described, data by nativity are limited. The National Immunization Survey is a random-digit-dialed telephone survey that estimates vaccination coverage among U.S. children aged 19-35 months. We assessed coverage among 52,441 children from pooled 2010-2012 data for individual vaccines and the combined 4:3:1:3*:3:1:4 series (which includes ≥4 doses of diphtheria, tetanus, and acellular pertussis vaccine/diphtheria and tetanus toxoids vaccine/diphtheria, tetanus toxoids, and pertussis vaccine, ≥3 doses of poliovirus vaccine, ≥1 dose of measles-containing vaccine, ≥3 or ≥4 doses of Haemophilus influenzae type b vaccine (depending on product type of vaccine; denoted as 3* in the series name), ≥3 doses of hepatitis B vaccine, ≥1 dose of varicella vaccine, and ≥4 doses of pneumococcal conjugate vaccine). Coverage estimates controlling for sociodemographic factors and multivariable logistic regression modeling for 4:3:1:3*:3:1:4 series completion are presented. Significantly lower coverage among foreign-born children was detected for DTaP, hepatitis A, hepatitis B, Hib, pneumococcal conjugate, and rotavirus vaccines, and for the combined series. Series completion disparities persisted after control for demographic, access-to-care, poverty, and language effects. Substantial and potentially widening disparities in vaccination coverage exist among foreign-born children. Improved immunization strategies targeting this population and continued vaccination coverage monitoring by nativity are needed.

Vaccine-preventable, hospitalizations among American Indian/Alaska Native children using the 2012 Kid's Inpatient Database

Our aim was to assess the odds of hospitalization for a vaccine-preventable, infectious disease (VP-ID) in American Indian/Alaska Native (AI/AN) children compared to other racial and ethnic groups using the 2012 Kid's Inpatient Database (KID) The KID is a nationally representative sample, which allows for evaluation of VP-ID in a non-federal, non-Indian Health Service setting. In a cross-sectional analysis, we evaluated the association of race/ethnicity and a composite outcome of hospitalization due to vaccine-preventable infection using multivariate logistic regression. AI/AN children were more likely (OR=1.81, 95% CI=1.34, 2.45) to be admitted to the hospital in 2012 for a VP-ID compared to Non-Hispanic white children after adjusting for age, sex, chronic disease status, metropolitan location, and median household income. This disparity highlights the necessity for a more comprehensive understanding of immunization and infectious disease exposure among American Indian children, especially those not covered or evaluated by Indian Health Service.

Human Papillomavirus Vaccine Uptake: Increase for American Indian Adolescents, 2013-2015

INTRODUCTION

Although Indian Health Service, tribally-operated, and urban Indian (I/T/U) healthcare facilities have higher human papillomavirus (HPV) vaccine series initiation and completion rates among adolescent patients aged 13-17 years than the general U.S. population, challenges remain. I/T/U facilities have lower coverage for HPV vaccine first dose compared with coverage for other adolescent vaccines, and HPV vaccine series completion rates are lower than initiation rates. Researchers aimed to assist I/T/U facilities in identifying interventions to increase HPV vaccination series initiation and completion rates.

STUDY DESIGN

Best practice and intervention I/T/U healthcare facilities were identified based on baseline adolescent HPV vaccine coverage data. Healthcare professionals were interviewed about barriers and facilitators to HPV vaccination. Researchers used responses and evidence-based practices to identify and assist facilities in implementing interventions to increase adolescent HPV vaccine series initiation and completion. Coverage and interview data were collected from June 2013 to June 2015; data were analyzed in 2015.

SETTING/PARTICIPANTS

I/T/U healthcare facilities located within five Indian Health Service regions.

INTERVENTION

Interventions included analyzing and providing feedback on facility vaccine coverage data, educating providers about HPV vaccine, expanding access to HPV vaccine, and establishing or expanding reminder recall and education efforts.

MAIN OUTCOME MEASURES

Impact of evidence-based strategies and best practices to support HPV vaccination.

RESULTS

Mean baseline first dose coverage with HPV vaccine at best practice facilities was 78% compared with 46% at intervention facilities. Mean third dose coverage was 48% at best practice facilities versus 19% at intervention facilities. Intervention facilities implemented multiple low-cost, evidence-based strategies and best practices to increase vaccine coverage. At baseline, most facilities used electronic provider reminders, had standing orders in place for administering HPV vaccine, and administered tetanus, diphtheria, and acellular pertussis and HPV vaccines during the same visit. At intervention sites, mean coverage for HPV initiation and completion increased by 24% and 22%, respectively.

CONCLUSIONS

A tailored multifaceted approach addressing vaccine delivery processes and patient and provider education may increase HPV vaccine coverage.

Increasing Incidence of Life-threatening Pertussis: A Retrospective Cohort Study in New Zealand

BACKGROUND

Pertussis immunization programs aim to prevent severe infant disease. We investigated temporal trends in infant pertussis deaths and pediatric intensive care unit (PICU) admissions and associations of changes in disease detection and vaccines used with death and PICU admission rates.

METHODS

Using national data from New Zealand (NZ), we described infant pertussis deaths and PICU admissions from 1991 to 2013, over which time national immunization coverage at 2 years of age increased from <80% to 92%. In NZ, pertussis became a notifiable disease with polymerase chain reaction (PCR) diagnosis available in 1997 and acellular replaced whole-cell vaccine in 2000. We used Poisson regression to model temporal trends and compared rates in time intervals using rate ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

There were 10 pertussis deaths and 159 infant PICU admissions with pertussis from 1991 to 2013. The annual number of infant pertussis PICU admissions increased from 1991 to 2013 (P = 0.02) but the number of pertussis deaths did not (P = 0.09). The risk of PICU admission during infancy with pertussis was increased in the notification/PCR versus the non-notification/PCR era (RR: 1.12; 95% CI: 1.02-1.19) and when acellular replaced whole-cell vaccine (RR: 1.19; 95% CI: 1.06-1.31). Median Pediatric Index of Mortality scores during 2001-2013 were lower than during 1991-1999 (P < 0.001).

CONCLUSIONS

Infant PICU pertussis admission rates have increased in NZ despite improvements in immunization coverage. Higher rates have occurred since pertussis notification/PCR became available and since acellular replaced whole-cell vaccine. The severity of disease in infants admitted to PICU with pertussis has decreased in recent years.

Child Health Disparities in the 21st Century

The topic of persistent child health disparities remains a priority for policymakers and a concern for pediatric clinicians. Health disparities are defined as differences in adverse health outcomes for specific health indicators that exist across sub-groups of the population, frequently between minority and majority populations. This review will highlight the gains that have been made since the 1990s as well as describe disparities that have persisted or have worsened into the 21st century. It will also examine the most potent social determinants and their impact on the major disparities in mortality, preventive care, chronic disease, mental health, educational outcomes, and exposure to selected environmental toxins. Each section concludes with a description of interventions and innovations that have been successful in reducing child health disparities.

Lower respiratory tract infection hospitalizations among American Indian/Alaska Native children and the general United States child population

BACKGROUND

The lower respiratory tract infection (LRTI)-associated hospitalization rate in American Indian and Alaska Native (AI/AN) children aged <5 years declined during 1998-2008, yet remained 1.6 times higher than the general US child population in 2006-2008.

PURPOSE

Describe the change in LRTI-associated hospitalization rates for AI/AN children and for the general US child population aged <5 years.

METHODS

A retrospective analysis of hospitalizations with discharge ICD-9-CM codes for LRTI for AI/AN children and for the general US child population <5 years during 2009-2011 was conducted using Indian Health Service direct and contract care inpatient data and the Nationwide Inpatient Sample, respectively. We calculated hospitalization rates and made comparisons to previously published 1998-1999 rates prior to pneumococcal conjugate vaccine introduction.

RESULTS

The average annual LRTI-associated hospitalization rate declined from 1998-1999 to 2009-2011 in AI/AN (35%, p<0.01) and the general US child population (19%, SE: 4.5%, p<0.01). The 2009-2011 AI/AN child average annual LRTI-associated hospitalization rate was 20.7 per 1,000, 1.5 times higher than the US child rate (13.7 95% CI: 12.6-14.8). The Alaska (38.9) and Southwest regions (27.3) had the highest rates. The disparity was greatest for infant (<1 year) pneumonia-associated and 2009-2010 H1N1 influenza-associated hospitalizations.

CONCLUSIONS

Although the LRTI-associated hospitalization rate declined, the 2009-2011 AI/AN child rate remained higher than the US child rate, especially in the Alaska and Southwest regions. The residual disparity is likely multi-factorial and partly related to household crowding, indoor smoke exposure, lack of piped water and poverty. Implementation of interventions proven to reduce LRTI is needed among AI/AN children.

American Indian and Alaska Native infant and pediatric mortality, United States, 1999-2009

OBJECTIVES

We described American Indian/Alaska Native (AI/AN) infant and pediatric death rates and leading causes of death.

METHODS

We adjusted National Vital Statistics System mortality data for AI/AN racial misclassification by linkage with Indian Health Service (IHS) registration records. We determined average annual death rates and leading causes of death for 1999 to 2009 for AI/AN versus White infants and children. We limited the analysis to IHS Contract Health Service Delivery Area counties.

RESULTS

The AI/AN infant death rate was 914 (rate ratio [RR] = 1.61; 95% confidence interval [CI] = 1.55, 1.67). Sudden infant death syndrome, unintentional injuries, and influenza or pneumonia were more common in AI/AN versus White infants. The overall AI/AN pediatric death rates were 69.6 for ages 1 to 4 years (RR = 2.56; 95% CI = 2.38, 2.75), 28.9 for ages 5 to 9 years (RR = 2.12; 95% CI = 1.92, 2.34), 37.3 for ages 10 to 14 years (RR = 2.22; 95% CI = 2.04, 2.40), and 158.4 for ages 15 to 19 years (RR = 2.71; 95% CI = 2.60, 2.82). Unintentional injuries and suicide occurred at higher rates among AI/AN youths versus White youths.

CONCLUSIONS

Death rates for AI/AN infants and children were higher than for Whites, with regional disparities. Several leading causes of death in the AI/AN pediatric population are potentially preventable.

Uptake of pneumococcal vaccines in the Nordic region of Nunavik, province of Quebec, Canada

OBJECTIVES

Pneumococcal infections constitute an important public health problem in Nordic regions of Canada. Nordic populations are not included in national and provincial immunization surveys and there is no centralized immunization registry in these regions. The objective of this study was to estimate pneumococcal vaccination coverage and delays in immunization of children in Nunavik, Quebec.

METHODS

Immunization records of children born in 1994-2005 were collected in all villages. Children were classified into three groups: born in the period January 1, 1994 to April 30, 1997 and targeted by the 2002 mass campaign with the 23-valent polysaccharide vaccine (PPSV23); born in the period May 1, 1997 to March 31, 2002 and targeted by the 7-valent conjugate vaccine (PCV7) catch-up campaign; born in the period April 1, 2002 to December 31, 2005 and targeted by the PCV7 routine infant program.

RESULTS

In the first group (n=896), 86.8% (95% CI: 84.4%-89.0%) were vaccinated with PPSV23. In the second group (n=1,252), 84.3% (95% CI: 82.1%-86.2%) received ≥1 PCV7 dose. In the third group, 90.4% (95% CI: 88.5%-92.1%) received 4 PCV7 doses. Delays >4 weeks in vaccine administration were observed for 26.3% of doses. There were substantial variations between villages for all indicators.

CONCLUSIONS

In the challenging setting of a Nordic and remote region, uptake rates of pneumococcal vaccines in Nunavik were found to be similar to those measured in population surveys in Quebec.

A prospective study of agents associated with acute respiratory infection among young American Indian children

BACKGROUND

Native American children have higher rates of morbidity associated with acute respiratory infection than children in the general US population, yet detailed information is lacking regarding their principal clinical presentations and infectious etiologies.

METHODS

We pursued a comprehensive molecular survey of bacteria and viruses in nasal wash specimens from children with acute respiratory disease collected prospectively over 1 year (January 1 through December 31, 2009) from 915 Navajo and White Mountain Apache children in their second or third year of life who had been enrolled in an efficacy study of a respiratory syncytial virus monoclonal antibody in the first year of life.

RESULTS

During the surveillance period, 1476 episodes of disease were detected in 669 children. Rates of outpatient and inpatient lower respiratory tract illness were 391 and 79 per 1000 child-years, respectively, and were most commonly diagnosed as pneumonia. Potential pathogens were detected in 88% of specimens. Viruses most commonly detected were respiratory syncytial virus and human rhinovirus; the 2009 pandemic influenza A (H1N1) illnesses primarily occurred in the fall. Streptococcus pneumoniae was detected in 60% of subjects; only human rhinovirus was significantly associated with S. pneumoniae carriage. The presence of influenza virus, human rhinovirus or S. pneumoniae was not associated with increased risk for lower respiratory tract involvement or hospitalization.

CONCLUSIONS

Acute lower respiratory illnesses occur at disproportionately high rates among young American Indian children and are associated with a range of common pathogens. This study provides critical evidence to support reducing the disproportionate burden of acute respiratory disease among young Native Americans.