Up-to-date Haemophilus influenzae type b vaccination coverage during a vaccine shortage

Consequences of a shortage and rationing: Evidence from a pediatric vaccine

Shortages and rationing are common in health care, yet we know little about the consequences. We examine an 18-month shortage of the pediatric Haemophilus Influenzae Type B (Hib) vaccine. Using insurance claims data and variation in shortage exposure across birth cohorts, we find that the shortage reduced uptake of high-value primary doses by 4 percentage points and low-value booster doses by 26 percentage points. This suggests providers largely complied with rationing recommendations. In the long-run, catch-up vaccination occurred but was incomplete: shortage-exposed cohorts were 4 percentage points less likely to have received the ir booster dose years later. We also find that the shortage and rationing caused provider switches, extra provider visits, and negative spillovers to other care.

Human papillomavirus vaccine initiation and up-to-date vaccine coverage for adolescents after the implementation of school-entry policy in Puerto Rico

The human papillomavirus (HPV) vaccine has been proven effective in the prevention of infection with high-risk HPV types, which can lead to the development of six HPV-related cancers. Puerto Rico (PR) adopted a mandatory HPV vaccination school-entry policy that took effect in August 2018. While school-entry requirements are generally accepted as an effective approach for increasing vaccination rates, there are few studies that have documented their impact on improving HPV vaccination rates. The objective of this study was to evaluate the impact of the HPV school-entry policy in PR on HPV vaccine coverage. We used a pre-post natural experiment. The study population included adolescents registered in the PR Immunization Registry during 2008-2019. We calculated HPV vaccine initiation and up-to-date (UTD) vaccine coverage rates. We estimated age-standardized rates (ASR) and standardized rate ratio with 95%CI. Vaccine data corresponding to a total of 495,327 adolescents were included for analysis; 50.9% were male and 49.1% were females. After policy implementation, a marked increase in raw HPV vaccine initiation among 11- to 12-year-old adolescents was observed across years 2017 (a pre-policy year), 2018, and 2019 (58.3%, 76.3%, and 89.8%, respectively). UTD coverage also showed a moderate increase after policy implementation among 11- to 12-year-old adolescents. The gap between sexes in vaccine initiation and UTD coverage narrowed over time; the ASRs in 2019 showed an increase of 19% in initiation and 7% increase in UTD relative to 2017 for males and females combined (both significant at p<0.05). This study demonstrated evidence of improvement in HPV vaccination rates following implementation of the school-entry policy and a narrowed sex gap in vaccine rates over time in PR. Future analyses should assess how the policy continues to affect vaccine coverage in subsequent years and how the COVID-19 pandemic has impacted HPV vaccination uptake.

Are we speaking the same language? an argument for the consistent use of terminology and definitions for childhood vaccination indicators

Vaccination indicators are used to measure the health status of individuals or populations and to evaluate the effectiveness of vaccination programs or policies. Ensuring that vaccination indicators are clearly and consistently defined is important for effective communication of outcomes, accurate program evaluation, and comparison between different populations, times, and contexts. The purpose of this commentary is to describe commonly used vaccination indicators and to highlight inconsistencies in how childhood vaccine researchers use and define these terms. The indicators we describe are vaccine coverage, uptake, and rate; vaccination status, initiation, and completion; and up-to-date, timely, partial, and incomplete vaccination. We conclude that many vaccination indicators are not explicitly defined within published research studies and/or are used quite differently across studies. We also note that the choice of indicator in a given study is often driven by program or vaccine specific factors, may be constrained by data availability, and should be chosen to best reflect the outcome of interest. We conclude that the use of consistent language and definitions would promote more effective communication of research findings. We also propose some standardized definitions for common indicators, with the goal of provoking discussion and debate on the issue.

U.S. vaccine and immune globulin product shortages, 2001-15

PURPOSE

Trends in shortages of vaccines and immune globulin products from 2001 through 2015 in the United States are described.

METHODS

Drug shortage data from January 2001 through December 2015 were obtained from the University of Utah Drug Information Service. Shortage data for vaccines and immune globulins were analyzed, focusing on the type of product, reason for shortage, shortage duration, shortages requiring vaccine deferral, and whether the drug was a single-source product. Inclusion of the product into the pediatric vaccination schedule was also noted.

RESULTS

Of the 2,080 reported drug shortages, 59 (2.8%) were for vaccines and immune globulin products. Of those, 2 shortages (3%) remained active at the end of the study period. The median shortage duration was 16.8 months. The most common products on shortage were viral vaccines (58%), especially hepatitis A, hepatitis B, rabies, and varicella vaccines (4 shortages each). A vaccine deferral was required for 21 shortages (36%), and single-source products were on shortage 30 times (51%). The most common reason for shortage was manufacturing problems (51%), followed by supply-and-demand issues (7%). Thirty shortages (51%) were for products on the pediatric schedule, with a median duration of 21.7 months.

CONCLUSION

Drug shortages of vaccines and immune globulin products accounted for only 2.8% of reported drug shortages within a 15-year period, but about half of these shortages involved products on the pediatric vaccination schedule, which may have significant public health implications.

Factors Associated With Provider Reporting of Child and Adolescent Vaccination History to Immunization Information Systems: Results From the National Immunization Survey, 2006-2012

CONTEXT

Use of Immunization information systems (IISs) by providers can improve vaccination rates by identifying missed opportunities. However, provider reporting of children's vaccination histories to IISs remains suboptimal.

OBJECTIVE

To assess factors associated with provider reporting to an IIS.

DESIGN

Analysis of 2006-2012 National Immunization Survey (NIS) and NIS-Teen data. NIS and NIS-Teen are ongoing random-digit-dial telephone surveys of households with children and adolescents, respectively, followed by a mail survey to providers to obtain the patient's vaccination history.

SETTING AND PARTICIPANTS

A total of 115 285 children aged 19 to 35 months and 83 612 adolescents aged 13 to 17 years and their immunization providers in the United States.

MAIN OUTCOME MEASURES

The percentage of children and adolescents with 1 or more providers reporting to or obtaining vaccination information from their local IISs. Multivariable logistic regression was used to examine patient and provider factors associated with provider reporting to IISs and adjusted prevalence of children and adolescents with 1 or more providers reporting to IISs.

RESULTS

In 2012, 79.4% of children and 77.4% of adolescents had 1 or more providers report any of their vaccination data to an IIS, and 41.9% of children and 51.5% of adolescents had providers who obtained any of their vaccination histories from an IIS. During 2006-2012, children and adolescents were more likely to have any of their vaccination data reported to an IIS if they received care from all public versus all private providers (children: 84.4% vs 69.6%, P < .0001; adolescents: 84.6% vs 66.4%, P < .0001), had 1 or more providers who ordered vaccines from a state or local health department (children: 76.7% vs 59.5%, P < .0001; adolescents: 77.0% vs 55.6%, P < .0001), or had 1 or more providers obtain vaccination information from the IIS (children: 86.1% vs 71.2%, P < .0001; adolescents: 83.7% vs 64.6%, P < .0001).

CONCLUSIONS

Health department staff should target providers less likely to use IIS services, including private providers, and providers not ordering vaccines from health departments to ensure they use IIS services.

Immunization information systems to increase vaccination rates: a community guide systematic review

CONTEXT

Immunizations are the most effective way to reduce incidence of vaccine-preventable diseases. Immunization information systems (IISs) are confidential, population-based, computerized databases that record all vaccination doses administered by participating providers to people residing within a given geopolitical area. They facilitate consolidation of vaccination histories for use by health care providers in determining appropriate client vaccinations. Immunization information systems also provide aggregate data on immunizations for use in monitoring coverage and program operations and to guide public health action.

EVIDENCE ACQUISITION

Methods for conducting systematic reviews for the Guide to Community Preventive Services were used to assess the effectiveness of IISs. Reviewed evidence examined changes in vaccination rates in client populations or described expanded IIS capabilities related to improving vaccinations. The literature search identified 108 published articles and 132 conference abstracts describing or evaluating the use of IISs in different assessment categories.

EVIDENCE SYNTHESIS

Studies described or evaluated IIS capabilities to (1) create or support effective interventions to increase vaccination rates, such as client reminder and recall, provider assessment and feedback, and provider reminders; (2) determine client vaccination status to inform decisions by clinicians, health care systems, and schools; (3) guide public health responses to outbreaks of vaccine-preventable disease; (4) inform assessments of vaccination coverage, missed vaccination opportunities, invalid dose administration, and disparities; and (5) facilitate vaccine management and accountability.

CONCLUSIONS

Findings from 240 articles and abstracts demonstrate IIS capabilities and actions in increasing vaccination rates with the goal of reducing vaccine-preventable disease.

Uptake of human papillomavirus vaccine among adolescent males and females: Immunization Information System sentinel sites, 2009-2012

OBJECTIVE

The Advisory Committee on Immunization Practices (ACIP) has recommended routine human papillomavirus (HPV) vaccination at age 11 or 12 years for girls since 2006 and for boys since 2011. We sought to describe adolescent HPV vaccination coverage, doses administered from 2009 to 2012, and age at first vaccination by sex.

METHODS

Aggregate data were analyzed from 8 Immunization Information System sentinel sites on HPV vaccinations in children and adolescents aged 11 to 12 years, 13 to 15 years, and 16 to 18 years. Vaccination coverage by age group was reported for 2009 to 2012, and weekly doses administered were determined. Age at first HPV vaccination was calculated for girls in 2007 and 2011 and for boys in 2011.

RESULTS

This analysis included data on 2.9 million adolescents aged 11 to 18 years. There were small increases in coverage for girls, with receipt of ≥1 dose of HPV vaccine reaching 27.1% of ages 11 to 12, 47.9% of ages 13 to 15, and 57.1% of ages 16 to 18 by December 31, 2012. Uptake of ≥1 dose in boys reached ∼18% for all age groups. Doses administered showed seasonal variation, with highest uptake before back to school among girls and steady increases in boys after the 2009 ACIP recommendation for permissive use. Doses administered to boys surpassed those administered to girls by September 2012. Among vaccinated girls, more received vaccine at the recommended age of 11 to 12 years in 2011 (74.2%) compared to 2007 (9.9%). In 2011, 27.3% of vaccinated boys received their first dose at age 11 to 12 years.

CONCLUSIONS

HPV vaccination coverage increased among adolescents between 2009 and 2012. However, increases among girls were small, and coverage for boys and girls remained below target levels.

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.

Haemophilus influenzae type b conjugate vaccines - a South African perspective

Introduction of Hib vaccine is known to positively impact on reduction of both morbidity and mortality in children less than 5 years of age. Incorporation of this vaccine into a National EPI, however, does come at a significant cost, which is especially important in non-GAVI funded countries. Compounded reduction in response in certain patient populations and possible indication of booster doses further impacts on cost-benefit analyses. Despite these issues, South Africa has supplied Hib vaccine as part of the National EPI in the form of a combination vaccine, Pentaxim, which combines Hib with Diphtheria, Tetanus, acellular Pertussis (DTP) and Poliomyelitis since 2009. Prior to this, another combination vaccine was utilized containing Hib and DTP. This has subsequently lead to a significant reduction in invasive Hib disease post-introduction, therefore largely justifying utilization.

Modeling insights into Haemophilus influenzae type b disease, transmission, and vaccine programs

Flexible simulation model use can optimize vaccination programs and response to changes in vaccine supply.

In response to the 2007–2009 Haemophilus influenzae type b (Hib) vaccine shortage in the United States, we developed a flexible model of Hib transmission and disease for optimizing Hib vaccine programs in diverse populations and situations. The model classifies population members by age, colonization/disease status, and antibody levels, with movement across categories defined by differential equations. We implemented the model for the United States as a whole, England and Wales, and the Alaska Native population. This model accurately simulated Hib incidence in all 3 populations, including the increased incidence in England/Wales beginning in 1999 and the change in Hib incidence in Alaska Natives after switching Hib vaccines in 1996. The model suggests that a vaccine shortage requiring deferral of the booster dose could last 3 years in the United States before loss of herd immunity would result in increasing rates of invasive Hib disease in children <5 years of age.

The impact of anti-infective drug shortages on hospitals in the United States: trends and causes

Anti-infective shortages pose significant logistical and clinical challenges to hospitals and may be considered a public health emergency. Anti-infectives often represent irreplaceable life-saving treatments. Furthermore, few new agents are available to treat increasingly prevalent multidrug-resistant pathogens. Frequent anti-infective shortages have substantially altered patient care and may lead to inferior patient outcomes. Because many of the shortages stem from problems with manufacturing and distribution, federal legislation has been introduced but not yet enacted to provide oversight for the adequate supply of critical medications. At the local level, hospitals should develop strategies to anticipate the impact and extent of shortages, to identify therapeutic alternatives, and to mitigate potential adverse outcomes. Here we describe the scope of recent anti-infective shortages in the United States and explore the reasons for inadequate drug supply.

Text4Health: impact of text message reminder-recalls for pediatric and adolescent immunizations

OBJECTIVES

We conducted 2 studies to determine the impact of text message immunization reminder-recalls in an urban, low-income population.

METHODS

In 1 study, text message immunization reminders were sent to a random sample of parents (n = 195) whose children aged 11 to 18 years needed either or both meningococcal (MCV4) and tetanus-diphtheria-acellular pertussis (Tdap) immunizations. We compared receipt of MCV4 or Tdap at 4, 12, and 24 weeks with age- and gender-matched controls. In the other study, we compared attendance at a postshortage Haemophilus influenzae B (Hib) immunization recall session between parents who received text message and paper-mailed reminders (n = 87) and those who only received paper-mailed reminders (n = 87).

RESULTS

Significantly more adolescents with intervention parents received either or both MCV4 and Tdap at weeks 4 (15.4% vs 4.2%; P < .001), 12 (26.7% vs 13.9%; P < .005), and 24 (36.4% vs 18.1%; P < .001). Significantly more parents who received both Hib reminders attended a recall session compared with parents who only received a mailed reminder (21.8% vs 9.2%; P < .05). After controlling for age, gender, race/ethnicity, insurance status, and language, text messaging was still significantly associated with both studies' outcomes.

CONCLUSIONS

Text messaging for reminder-recalls improved immunization coverage in a low-income, urban population.

Effects of a nationwide Hib vaccine shortage on vaccination coverage in the United States

BACKGROUND

A shortage of Haemophilus influenzae type b (Hib) vaccine that occurred in the United States during December 2007 to September 2009 resulted in an interim recommendation to defer the booster dose, but to continue to vaccinate as recommended with the primary series during the first year of life.

OBJECTIVES

To quantify effects of the Hib shortage on vaccination coverage and to determine if any demographic subgroups were disproportionately affected.

METHODS

Data from the 2009 National Immunization Survey (NIS) were divided based on child's age at the onset of the shortage. Comparisons were made in primary series coverage by 9 months between children <7 months versus ≥7 months at the start of the shortage. Comparisons in primary series plus booster dose completion by 19 months were made between children who were <12 months versus ≥12 months at the start of the shortage.

RESULTS

Nationally, there was a difference in Hib primary series completion by 9 months among children age <7 months versus ≥7 months at the start of the shortage (73.9% versus 81.2%, P<0.001). There was a large difference in the percentage of children fully vaccinated with the primary series plus booster dose by 19 months among children age <12 months versus ≥12 months at the start of the shortage (39.5% versus 66.0%, P<0.001). There were differential effects of the shortage on primary series coverage among states and for some demographic characteristics.

CONCLUSIONS

As expected booster dose coverage was reduced consistent with interim recommendations, but primary series coverage was also reduced by 7 percentage points nationally.

Highlights of historical events leading to national surveillance of vaccination coverage in the United States

The articles published in this special supplement of Public Health Reports provide examples of only some of the current efforts in the United States for evaluating vaccination coverage. So, how did we get here? The history of vaccination and assessment of vaccination coverage in the U.S. has its roots in the pre-Revolutionary War era. In many cases, development of vaccines, and attention devoted to the assessment of vaccination coverage, has grown from the impact of infectious disease on major world events such as wars. The purpose of this commentary is to provide a brief overview of the key historical events in the U.S. that influenced the development of vaccines and the efforts to track vaccination coverage, which laid the foundation for contemporary vaccination assessment efforts.

Haemophilus influenzae type b infection, vaccination, and H. influenzae carriage in children in Minnesota, 2008-2009

An increase in invasive Haemophilus influenzae type b (Hib) cases occurred in Minnesota in 2008 after the recommended deferral of the 12-15 months Hib vaccine boosters during a US vaccine shortage. Five invasive Hib cases (one death) occurred in children; four had incomplete Hib vaccination (three refused/delayed); one was immunodeficient. Subsequently, we evaluated Hib carriage and vaccination. From 18 clinics near Hib cases, children (aged 4 weeks-60 months) were surveyed for pharyngeal Hib carriage. Records were compared for Hib, diphtheria-tetanus-acellular pertussis (DTaP), and pneumococcal (PCV-7) vaccination. Parents completed questionnaires on carriage risk factors and vaccination beliefs. In 1631 children (February-March 2009), no Hib carriage was detected; Hib vaccination was less likely to be completed than DTaP and PCV-7. Non-type b H. influenzae, detected in 245 (15%) children, was associated with: male sex, age 24-60 months, daycare attendance >15 h/week, a household smoker, and Asian/Pacific Islander race/ethnicity. In 2009, invasive Hib disease occurred in two children caused by the same strain that circulated in 2008. Hib remains a risk for vulnerable/unvaccinated children, although Hib carriage is not widespread in young children.