Measure Vaccination Coverage Research Articles

Childhood Vaccination Coverage Rates Among Military Dependents in the United States

The Military Health System provides universal coverage of all recommended childhood vaccinations. Few studies have examined the effect that being insured by the Military Health System has on childhood vaccination coverage. The purpose of this study was to compare the coverage of the universally recommended vaccines among military dependents versus other insured and uninsured children using a nationwide sample of children. The National Immunization Survey is a multistage, random-digit dialing survey designed to measure vaccination coverage estimates of US children aged 19 to 35 months old. Data from 2007 through 2012 were combined to permit comparison of vaccination coverage among military dependent and all other children. Among military dependents, 28.0% of children aged 19 to 35 months were not up to date on the 4:3:1:3:3:1 vaccination series excluding Haemophilus influenzae type b vaccine compared with 21.1% of all other children (odds ratio: 1.4; 95% confidence interval: 1.2-1.6). After controlling for sociodemographic characteristics, compared with all other US children, military dependent children were more likely to be incompletely vaccinated (odds ratio: 1.3; 95% confidence interval: 1.1-1.5). Lower vaccination coverage rates among US military dependent children might be due to this population being highly mobile. However, the lack of a military-wide childhood immunization registry and incomplete documentation of vaccinations could contribute to the lower vaccination coverage rates seen in this study. These results suggest the need for further investigation to evaluate vaccination coverage of children with complete ascertainment of vaccination history, and if lower immunization rates are verified, assessment of reasons for lower vaccination coverage rates among military dependent children.

O19.5 Assessing the Effectiveness of the Human Papillomavirus (HPV) Vaccination Programme in Victoria, Australia

BackgroundQuadrivalent HPV vaccination has been available in Australia through the National HPV Vaccination Program since 2007. The VACCINE study aims to evaluate the effectiveness of the programme by assessing the...

Measuring Coverage in MNCH: Design, Implementation, and Interpretation Challenges Associated with Tracking Vaccination Coverage Using Household Surveys

Vaccination coverage is an important public health indicator that is measured using administrative reports and/or surveys. The measurement of vaccination coverage in low- and middle-income countries using surveys is susceptible to numerous challenges. These challenges include selection bias and information bias, which cannot be solved by increasing the sample size, and the precision of the coverage estimate, which is determined by the survey sample size and sampling method. Selection bias can result from an inaccurate sampling frame or inappropriate field procedures and, since populations likely to be missed in a vaccination coverage survey are also likely to be missed by vaccination teams, most often inflates coverage estimates. Importantly, the large multi-purpose household surveys that are often used to measure vaccination coverage have invested substantial effort to reduce selection bias. Information bias occurs when a child's vaccination status is misclassified due to mistakes on his or her vaccination record, in data transcription, in the way survey questions are presented, or in the guardian's recall of vaccination for children without a written record. There has been substantial reliance on the guardian's recall in recent surveys, and, worryingly, information bias may become more likely in the future as immunization schedules become more complex and variable. Finally, some surveys assess immunity directly using serological assays. Sero-surveys are important for assessing public health risk, but currently are unable to validate coverage estimates directly. To improve vaccination coverage estimates based on surveys, we recommend that recording tools and practices should be improved and that surveys should incorporate best practices for design, implementation, and analysis.

Adult immunization policies in advanced economies: vaccination recommendations, financing, and vaccination coverage.

ObjectivesWhile many countries have robust child immunization programs and high child vaccination coverage, vaccination of adults has received less attention. The objective of this study was to describe the adult vaccination policies in developed countries.MethodsFrom 2010 to 2011, we conducted a survey of 33 advanced economies as defined by the International Monetary Fund. The survey asked about national recommendations for adults for 16 vaccines or vaccine components, funding mechanisms for recommended adult vaccines, and the availability of adult vaccination coverage estimates.ResultsThirty-one of 33 (93.9 %) advanced economies responded to the survey. Twelve of 31 (38.7 %) reported having a comprehensive adult immunization schedule. The total number of vaccines or vaccine components recommended for adults ranged from one to 15 with a median of 10. Seasonal influenza (n = 30), tetanus (n = 28), pneumococcal polysaccharide (n = 27), and hepatitis B (n = 27) were the most frequently recommended vaccines or components.ConclusionsApproximately two-thirds of survey respondents do not have a comprehensive adult vaccine schedule, and most do not measure vaccination coverage. We found that a funding mechanism is available for most recommended adult vaccines.Electronic supplementary materialThe online version of this article (doi:10.1007/s00038-012-0438-x) contains supplementary material, which is available to authorized users.

Estimating vaccination coverage in the absence of immunisation registers – the German experience

Immunisation registers are regarded as an appropriate solution to measure vaccination coverage on a population level. In Germany, a decentralised healthcare system and data protection regulations constrain such an approach. Moreover, shared responsibilities in the process of immunisation and multiple providers form the framework for public health interventions on vaccination issues. On the national level, those interventions consist mainly of conceptualising immunisation strategies, establishing vaccination programmes, and issuing recommendations. This paper provides an overview on sources and methods for collecting appropriate coverage data at national level and their public health relevance in Germany. Methods of data collection and available information on immunisations are described for three approaches: school entrance health examination, population surveys and insurance refund claim data. School entrance health examinations allow regional comparisons and estimation of trends for a specific cohort of children and for all recommended childhood vaccinations. Surveys deliver population based data on completeness and timeliness of selected vaccinations in populations defined by age or socio-demographic parameters and on knowledge and attitudes towards vaccination. Insurance refund claim data inform continuously on immunisation status (e.g. of children aged two years) or on vaccination incidence promptly after new or modified recommendations. In a complex healthcare system, the German National Public Health Institute (Robert Koch Institute, RKI) successfully compiles coverage data from different sources, which complement and validate one another. With the German approach of combining different data sources in the absence of immunisation registers, it is possible to gain solid and reliable data on the acceptance of vaccination programmes and target groups for immunisation. This approach might be of value for other countries with decentralised healthcare systems.

Measuring vaccination coverage in a hard to reach minority

Although childhood vaccination programmes have been very successful, there are some hard to reach minority groups that object to vaccination. The Netherlands has experienced several epidemics of vaccine-preventable diseases, confined to the orthodox Protestant minority. However, vaccination coverage in this minority is still unknown and this hampers prevention and control of epidemics. We estimated vaccination coverage among the orthodox Protestant minority and its various subgroups (denominations), using two sub-studies with different design and study population. For both sub-studies separately, we determined overall vaccination coverage and vaccination coverage per denomination. The results were compared and discussed. An online survey was filled out by 1778 orthodox Protestant youngsters, invited via orthodox Protestant media using a snowball method. Next to that, results of a national sample study on vaccination were used, of which only orthodox Protestant respondents were included in our analyses (N = 2129). Overall vaccination coverage among orthodox Protestants in The Netherlands was estimated to be at minimum 60%. Moreover, in both sub-studies three clusters of denominations could be identified, with high (>85%), intermediate (50-75%) and low (<25%) vaccination coverage. The integration of both sub-studies, with their own specific strengths and weaknesses, added to our insight in the vaccination coverage in this minority. Based on these results, we recommend to focus prevention and control of vaccine-preventable diseases on the orthodox Protestant subgroups with intermediate and low vaccination coverage.

Old and new cluster designs in emergency field surveys: in search of a one-fits-all solution

IntroductionCluster surveys are frequently used to measure key nutrition and health indicators in humanitarian emergencies. The survey design of 30 clusters of 7 children (30 × 7) was initially proposed by the World Health Organization for measuring vaccination coverage, and later a design of 30 clusters of 30 children (30 × 30) was introduced to measure acute malnutrition in emergency settings. Recently, designs of 33 clusters of 6 children (33 × 6) and 67 clusters of 3 children (67 × 3) have been proposed as alternatives that enable measurement of several key indicators with sufficient precision, while offering substantial savings in time. This paper explores expected effects of using 67 × 3, 33 × 6, or 30 × 7 designs instead of a "standard" 30 × 30 design on precision and accuracy of estimates, and on time required to complete the survey.AnalysisThe 67 × 3, 33 × 6, and 30 × 7 designs are expected to be more statistically efficient for measuring outcomes having high design effects (e.g., vaccination coverage, vitamin A distribution coverage, or access to safe water sources), and less efficient for measuring outcomes with more within-cluster variability, such as global acute malnutrition or anemia. Because of small sample sizes, these designs may not provide sufficient levels of precision to measure crude mortality rates. Given the small number (3 to 7) of survey subjects per cluster, it may be hard to select representative samples of subjects within clusters.The smaller sample size in these designs will likely result in substantial time savings. The magnitude of the savings will depend on several factors, including the average travel time between clusters. The 67 × 3 design will provide the least time savings. The 33 × 6 and 30 × 7 designs perform similarly to each other, both in terms of statistical efficiency and in terms of time required to complete the survey.ConclusionCluster designs discussed in this paper may offer substantial time and cost savings compared to the traditional 30 × 30 design, and may provide acceptable levels of precision when measuring outcomes that have high intracluster homogeneity. Further investigation is required to determine whether these designs can consistently provide accurate point estimates for key outcomes of interest. Organizations conducting cluster surveys in emergency settings need to build their technical capacity in survey design to be able to calculate context-specific sample sizes individually for each planned survey.

Delivering Adolescent Vaccinations in the Medical Home: A New Era?

Medical homes are health care settings that offer continuous, comprehensive, accessible primary care; these settings generally involve pediatric and family physician practices or community health centers but can also involve gynecologists or internists. In this article, we review available evidence on the role of the medical home in optimizing adolescent immunization delivery, particularly with respect to health care utilization patterns and barriers to vaccinations in medical homes, and solutions. We conducted a systematic review of the existing immunization and adolescent literature and used a Delphi process to solicit opinions from content experts across the United States. Most adolescents across the United States do have a medical home, and many pay a health care visit to their medical home within any given year. Barriers exist in regards to the receipt of adolescent immunizations, and they are related to the adolescent/family, health care provider, and health care system. Although few studies have evaluated adolescent vaccination delivery, many strategies recommended for childhood or adult vaccinations should be effective for adolescent vaccination delivery as well. These strategies include education of health care providers and adolescents/parents; having appropriate health insurance coverage; tracking and reminder/recall of adolescents who need vaccination; practice-level interventions to ensure that needed vaccinations are provided to eligible adolescents at the time of any health care visit; practice-level audits to measure vaccination coverage; and linkages across health care sites to exchange information about needed vaccinations. Medical homes should perform a quality improvement project to improve their delivery of adolescent vaccinations. Because many adolescents use a variety of health care sites, it is critical to effectively transfer vaccination information across health care settings to identify adolescents who are eligible for vaccinations and to encourage receipt of comprehensive preventive. Medical homes are integral to both the delivery of adolescent immunizations and comprehensive adolescent preventive health care. Many strategies recommended for childhood and adult vaccinations should work for adolescent vaccinations and should be evaluated and implemented if they are successful. By incorporating evidence-based strategies and coordinating effectively with other health care sites used by adolescents, medical homes will be the pivotal settings for the delivery of adolescent vaccinations.

Measuring Vaccination Coverage—Where Are We Now and Where Are We Going?

In Brief This editorial calls for a robust assessment system to provide timely and high-quality data to continually identify gaps, improve vaccination coverage, provide accountability to the public, and ultimately reduce the health and financial burdens of vaccine-preventable diseases.

Influenza and Pneumococcal Vaccine Coverages in Geriatric Health Care Settings in France

Background: Annual immunization with influenza vaccine is effective in preventing influenza-associated mortality and morbidity in the elderly. Pneumococcal vaccination is also considered as an effective strategy to decrease pneumococcal-associated diseases and mortality, particularly in the geriatric health care setting. However, in France, influenza and pneumococcal vaccination coverage in senior citizens living in long-term care facilities has not been comprehensively evaluated. Objectives: A prospective multicenter study was conducted to measure influenza and pneumococcal vaccine coverage and to assess the existence of local recommendations and the reasons for reluctance to immunize patients in geriatric health care settings in France. Two questionnaires were developed: the initial questionnaire to record the demographic characteristics of patients in health care facilities and to note influenza and pneumococcal vaccine coverage, and a second questionnaire, sent to all responders in June 2003, to record the number and causes of death (December 2002 to April 2003). Questions about the reasons for non-vaccination were added to all settings which had pneumococcal or influenza vaccination coverages below the median levels in the first query. Results: 105 health care facilities measuring vaccine coverage in 7,882 elderly patients participated in the study. Of 105 units, 9 were acute care units (n = 203 patients), 22 rehabilitation care units (n = 923), 68 long-term care facilities (n = 6,458), and 6 nursing homes (n = 315). The median and mean age of patients was 83 (SD 3.5) years. Influenza and pneumococcal vaccine rates were 87.7% (median 90%, range 0–100%) and 21.9% (median 2.8%, range 0–100%), respectively. There were significant differences between the type of setting and wide variability. There was no correlation between vaccine coverage and local recommendations. Mortality was 15.2% and was negatively correlated with influenza vaccine. The reasons for non-vaccination evaluated in 20 units differed for influenza and pneumococcal vaccine. Conclusion: Influenza vaccine coverage is high in long-term care settings but not in other settings. Pneumococcal vaccine coverage is very low in most settings, in part because of the lack of positive recommendations in France. Annual vaccination records are needed and should be a goal for the National Health Care Department. In addition, reasons for failure to administer both vaccines should be precisely evaluated on large populations to improve vaccination coverage.

Wanted: studies on mortality estimation methods for humanitarian emergencies, suggestions for future research

Measuring rates and circumstances of population mortality (in particular crude and under-5 year mortality rates) is essential to evidence-based humanitarian relief interventions. Because prospective vital event registration is absent or deteriorates in nearly all crisis-affected populations, retrospective household surveys are often used to estimate and describe patterns of mortality. Originally designed for measuring vaccination coverage, the two-stage cluster survey methodology is frequently employed to measure mortality retrospectively due to limited time and resources during humanitarian emergencies. The method tends to be followed without considering alternatives, and there is a need for expert advice to guide health workers measuring mortality in the field.In a workshop in France in June 2006, we deliberated the problems inherent in this method when applied to measure outcomes other than vaccine coverage and acute malnutrition (specifically, mortality), and considered recommendations for improvement. Here we describe these recommendations and outline outstanding issues in three main problem areas in emergency mortality assessment discussed during the workshop: sampling, household data collection issues, and cause of death ascertainment. We urge greater research on these issues. As humanitarian emergencies become ever more complex, all agencies should benefit from the most recently tried and tested survey tools.

Comparison of two survey methodologies to assess vaccination coverage

Measuring vaccination coverage permits evaluation and appropriate targeting of vaccination services. The cluster survey methodology developed by the World Health Organization, known as the 'Expanded Program on Immunization (EPI) methodology', has been used worldwide to assess vaccination coverage; however, the manner in which households are selected has been criticized by survey statisticians as lacking methodological rigor and introducing bias. Thirty clusters were selected from an urban (Ambo) and a rural (Yaya-Gulelena D/Libanos) district of Ethiopia; vaccination coverage surveys were conducted using both EPI sampling and systematic random sampling (SystRS) of households. Chi-square tests were used to compare results from the two methodologies; relative feasibility of the sampling methodologies was assessed. Vaccination coverage from a recent measles campaign among children aged 6 months through 14 years was high: 95% in Ambo (both methodologies), 91 and 94% (SystRS and EPI sampling, respectively, P-value = 0.05) in Yaya-Gulelena D/Libanos. Coverage with routine vaccinations among children aged 12-23 months was <20% in both districts; in Ambo, EPI sampling produced consistently higher estimates of routine coverage than SystRS. Differences between the two methods were found in demographic characteristics and recent health histories. Average time required to complete a cluster was 16h for EPI sampling and 17 h for SystRS; total cost was equivalent. Interviewers reported slightly more difficulty conducting SystRS. Because of the methodological advantages and demonstrated feasibility, SystRS would be preferred to EPI sampling in most situations. Validating results in additional settings is recommended.

Vaccine coverage with hepatitis B and other vaccines in the Colombian Amazon: do health worker knowledge and perception influence coverage?

We conducted a vaccination coverage survey in the Colombian Amazon, an area highly endemic for hepatitis B (HB), where HB vaccine was introduced in 1992. The aim was to measure vaccine coverage and factors influencing it, especially those related to health services. A total of 3573 children younger than 11 years were randomly selected from four populations. Vaccination status was ascertained through the vaccination card and a questionnaire on socio-demographic factors was applied to children's caretakers. Health workers (HW) in charge of vaccination in rural and urban areas were interviewed regarding knowledge and practices in vaccination. Individual and HW characteristics were related to individual vaccination using logistic regression. Overall cumulated vaccination coverage was high for polio (96%, 95% CI: 94-98), measles (94%, 95% CI: 92.8-95.2), BCG (91%, 95% CI: 90-93), DPT (90%, 95% CI: 88-92) and HB (88%, 95% CI: 86-90). However, <50% of children completed the primary course of vaccination in the first year of life. Individual factors improving the likelihood of being either fully or HB vaccinated were: age>1 year, living in Leticia, being affiliated to the social security, and living in a house with a roof made of tiles rather than palm tree leaf. Among the variables related to HWs, poor knowledge of vaccine contraindications predicted a lower chance of being fully or HB vaccinated in the population served by them, even after controlling for individual variables. The HB control program in Colombia has achieved good coverage in one of the most endemic areas of the country. However, barriers to vaccination arise from inequities in the distribution of health insurance and inadequate HW knowledge.

The information network of senior citizens in Geneva, Switzerland, and progress in flu vaccination coverage between 1991 and 2000

Switzerland has lagged behind other industrialized countries in increasing vaccination coverage against flu in the elderly population. The information campaign “United against Flu”, started in Geneva in 1993, gradually extended to other French and Italian speaking cantons in Switzerland and indirectly affected German-speaking cantons. Activities developed include the production of TV spots, press conferences, information forwarded to health professionals, an Internet site and information material such as leaflets and posters to risk groups. The campaign is evaluated by repeated surveys that measure vaccination coverage as well as network of informants, knowledge and perceptions in the geriatric population. Vaccination coverage of the geriatric population in Geneva canton has increased from 29% in 1991 to 59% in the year 2000.

Vaccination coverage of foreign-born children 19 to 35 months of age: findings from the National Immunization Survey, 1999-2000.

To compare coverage estimates of foreign-born children 19 to 35 months old with those of US-born children of the same age group. The National Immunization Survey is a multistage, random-digit dialing survey designed to measure vaccination coverage estimates of US children 19 to 35 months old. Data from 1999-2000 were combined to permit comparison of vaccination coverage among foreign- and US-born children. Foreign-born and US-born children 19 to 35 months of age had comparable 3:3:1 series coverage (3 or more doses of diphtheria and tetanus toxoids and pertussis vaccine [DTP/DTaP/DT], 3 or more doses of poliovirus vaccine, and 1 or more doses of measles-containing vaccine), the standard in most countries. However, coverage for a US standard, 4:3:1:3 series (4 or more doses of DTP/DTaP/DT, 3 or more doses of poliovirus vaccine, 1 or more doses of measles-containing vaccine, and an adequate number of Haemophilus influenzae type b [Hib] doses based on age at first dose) was lower among foreign-born children because of markedly lower Hib cover and marginally lower DTP/DTaP/DT coverage. In addition, hepatitis B coverage was markedly lower in foreign-born children. Lower vaccination coverage among foreign-born children, especially against Hib and hepatitis B, is of concern because foreign-born children often live in households and communities characterized by more intense exposure to these diseases, and many originate from countries with much higher prevalence rates of these diseases than the United States. The differences in Hib and hepatitis B coverage suggest a need for increased culturally competent public health immunization interventions to increase coverage among foreign-born children.

The impact of record scattering on the measurement of immunization coverage.

Lack of a consolidated immunization record may lead to problems with determining individual immunization needs at office visits as well as measuring vaccination coverage levels of a clinician's practice or a community's population. For children with multiple immunization providers, evaluate the difference in coverage levels using data from all responding immunization providers compared with: 1) the most recent immunization provider's records, 2) the first immunization provider's records, and 3) a randomly selected immunization provider's records. Identify characteristics of the most recent provider that may be associated with reporting incomplete immunization histories. Data from the 1995 National Immunization Provider Record Check Study (NIPRCS) were used for analysis. The NIPRCS is a provider validation study of the household reported immunization histories of all children 19 to 35 months of age included in the National Health Interview Survey (NHIS). Providers identified by the child's parent during the NHIS interview are mailed a 2-page survey to report all immunizations (type and date) the child received, regardless of the provider who administered the shots, and child's first and most recent visit dates to the practice. Of the 1352 children with provider data, 304 (22%) had received immunizations from more than one provider. Compared with information from all providers and depending on the vaccine, the most recent provider records underestimated coverage by 9.6 to 13.4 percentage points; the initial provider records underestimated coverage by 15.6 to 34.6 percentage points; and the randomly selected provider records underestimated coverage by 10.0 to 20.7 percentage points. Public facilities and having an immunization summary sheet in the patient's chart were associated with having complete records. Scattered immunization records significantly compromise the ability of clinicians to determine the immunization status of their patients who received immunizations at other sites of health care. Routinely assessing immunization coverage levels at the practice level, implementing a recall system, and developing community-wide immunization registries are some strategies to reduce the problem of scattered immunization records.immunization, assessment, provider validation, record scattering.

National Immunization Survey: the methodology of a vaccination surveillance system.

The National Immunization Survey (NIS) was designed to measure vaccination coverage estimates for the US, the 50 states, and selected urban areas for children ages 19-35 months. The NIS includes a random-digit-dialed telephone survey and a provider record check study. Data are weighted to account for the sample design and to reduce nonresponse and non-coverage biases in order to improve vaccination coverage estimates. Adjustments are made for biases resulting from nonresponse and nontelephone households, and estimation procedures are used to reduce measurement bias. The NIS coverage estimates represent all US children, not just children living in households with telephones. NIS estimates are highly comparable to vaccination estimates derived from the National Health Interview Survey. The NIS allows comparisons between states and urban areas over time and is used to evaluate current and new vaccination strategies.

Control of poliomyelitis in Africa.

In Africa, an estimated 168,000 children are disabled by poliomyelitis every year. With the use of lameness surveys to estimate incidence before immunization, surveys to measure vaccination coverage, and surveillance to monitor disease trends, poliomyelitis control in Yaound é, Cameroon; The Gambia; and Abidjan, Ivory Coast was examined. Three doses of oral poliovirus vaccine have been administered to 50%-70% of the children. The incidence of poliomyelitis has decreased significantly. Oral poliovirus vaccine administered during the first year of life has been effective in controlling poliomyelitis in tropical Africa.