Immunization Coverage Levels Research Articles

Effect of a School-Entry Vaccination Requirement on Racial and Ethnic Disparities in Hepatitis B Immunization Coverage Levels Among Public School Students

We evaluated the overall effect of Illinois' school-entry mandate on hepatitis B vaccination coverage levels and racial/ethnic differences in vaccination coverage before and after the mandate. In 1997, the Illinois Department of Public Health mandated hepatitis B vaccination before entry into 5th grade. We conducted a retrospective cohort study of 6 consecutive Chicago public schools' 12th-grade classes; 4 entered 5th grade before the mandate (premandate cohorts) and 2 afterward (postmandate cohorts). We used Chicago public schools' vaccination database and calculated annual coverage levels for 2nd through 12th grades; the cohorts entered 12th grade during 2000-2005. We compared hepatitis B vaccination coverage levels according to race/ethnicity and coverage levels for the premandate and postmandate cohorts. We evaluated 106 541 students. The postmandate cohort had significantly higher hepatitis B vaccination coverage levels than the premandate cohort at 5th-grade (38.2% vs 4.3%) and 9th-grade (85.0% vs 37.4%) entry. For 9th-grade students, compared with white students, black students were less likely to have received hepatitis B vaccination before the mandate; this disparity decreased for the first postmandate cohort. For Hispanic students, the disparity was less pronounced and also decreased after the mandate. By 9th grade in the postmandate cohorts, coverage levels for all racial/ethnic groups exceeded 80%. There was a dramatic decrease in the disparity of hepatitis B vaccination coverage between white and black or Hispanic students. School-entry requirements effectively increased hepatitis B vaccination coverage levels regardless of race or ethnicity and should be considered for other recently recommended adolescent vaccines.

Vaccination coverage among kindergarten children in Phoenix, Arizona

Objective To evaluate school immunization records and document the immunization coverage and compliance level of children enrolled in kindergarten in Phoenix during the 2001—2002 school year. The purpose was to obtain information on: 1) immunization status by age two; 2) under-immunization in kindergarten; 3) administration error; and 4) transcription error. Methods Vaccination levels were estimated by conducting a retrospective immunization coverage survey of the immunization records of children in SW, SE, NE, and NW regions of Phoenix. A two-stage cluster design was used. Schools were randomly selected with the regions and students were systematically selected within the schools. Setting Twelve schools from Phoenix were surveyed. Immunization records for 865 student records were assessed. Children who had incomplete or unknown records were identified. Information on date of birth and dates of vaccination of each dose of vaccine was collected. Results Of the 857 records included in the analyses, 30.6 per cent were from the NE, 19.9 per cent from the NW, 17.8 per cent from the SE and 31.7 per cent were from the SW. Private school students comprised 18.4 per cent of the sample, 78.3 per cent were from public schools and 3.4 per cent from charter schools. Examining the sample, 30.5 per cent did not have the shots required by age two (four Dtap, three Polio, one MMR), 11.4 per cent of shots were administered before the minimum age and/or interval, 16.0 per cent did not have the shots required for entrance to kindergarten (four Dtap, three Polio, two MMR, three HEP B) and 10.8 per cent of the records contained transcription errors. Conclusion The data showed that vaccination rates varied by region. None of the schools were in full compliance with the Arizona goal of 95 per cent of all kindergarten students being up to date. The vaccination levels were also below the National 2010 goal of 90 per cent by age two. The high administration error rate indicates that providers need to administer vaccines according to the recommended schedule. Further assessment must be done to determine effective interventions to target specific populations.

Evaluation of primary immunization coverage of infants under universal immunization programme in an urban area of Bangalore city using cluster sampling and lot quality assurance sampling techniques

Research Question:Is LQAS technique better than cluster sampling technique in terms of resources to evaluate the immunization coverage in an urban area?Objective:To assess and compare the lot quality assurance sampling against cluster sampling in the evaluation of primary immunization coverage.Study Design:Population-based cross-sectional study.Study Setting:Areas under Mathikere Urban Health Center.Study Subjects:Children aged 12 months to 23 months.Sample Size:220 in cluster sampling, 76 in lot quality assurance sampling.Statistical Analysis:Percentages and Proportions, Chi square Test.Results:(1) Using cluster sampling, the percentage of completely immunized, partially immunized and unimmunized children were 84.09%, 14.09% and 1.82%, respectively. With lot quality assurance sampling, it was 92.11%, 6.58% and 1.31%, respectively. (2) Immunization coverage levels as evaluated by cluster sampling technique were not statistically different from the coverage value as obtained by lot quality assurance sampling techniques. Considering the time and resources required, it was found that lot quality assurance sampling is a better technique in evaluating the primary immunization coverage in urban area.

Out-of-Pocket Costs of Childhood Immunizations: A Comparison by Type of Insurance Plan

The "Guide to Community Preventive Services" strongly recommends reducing out-of-pocket costs to increase vaccination rates among children. Nevertheless, out-of-pocket expenses are still incurred during the receipt of childhood vaccines, vaccine administration, and associated well-child visits. Our goal was to estimate total and out-of-pocket costs of childhood immunization. We used the 2003 benefit-plan data for all 1217 private and public health plans registered in Georgia and the 2003 Advisory Committee on Immunization Practices recommended vaccine schedule to calculate costs to vaccinate children aged 0 to 5 years in 2003 dollars. By applying published estimates of health insurance enrollment of Georgia children, we calculated the total and out-of-pocket costs per child according to insurance status and race/ethnicity. Immunization coverage according to payer type was based on National Immunization Survey data. Out-of-pocket costs ranged between $0 (Medicaid/Peachcare) and $652 (uninsured/Medicare). Most out-of-pocket costs were incurred during the first year of life. Up-to-date immunization status ranged from 63.7% for uninsured persons to 83.2% for privately insured persons. Up-to-date status was negatively correlated with out-of-pocket costs and the proportion of the population below 250% of the federal poverty level. For most Georgia families, out-of-pocket expenses for childhood immunizations were low, favoring compliance with the recommended immunization schedule. However, families least able to afford the expense faced disproportionately high out-of-pocket costs. Out-of-pocket costs were inversely correlated with immunization coverage levels. Uninsured children whose families lived below 250% of the federal poverty level experienced the lowest immunization coverage levels. Immunization coverage through the Vaccines for Children Program and Medicaid/State Children's Health Insurance Programs should be promoted to minimize or eliminate out-of-pocket costs related to childhood immunizations, especially among children of low-income families.

Childhood Immunization Coverage by Provider Type

To determine how child characteristics and immunization coverage levels differ among children using public and private providers. Immunization coverage rates between 1996 and 2004 were compared among children aged 19-35 months, using data from the National Immunization Survey. Coverage was based on the 4:3:1:3:3 vaccine series: four or more doses of diphtheria, tetanus toxoids, acellular pertussis vaccine; three or more doses of poliovirus vaccine; one or more doses of measles-mumps-rubella vaccine; three or more doses of Haemophilus influenzae type b vaccine; and three or more doses of hepatitis B vaccine. Coverage differences were examined by provider types (child vaccinated by private, public, or a mix of providers), and stratified by child's race/ethnicity, area of residence, and household income level. Between 1996 and 2004, the proportion of children seeing exclusively private providers increased (58%-61%; P < .05); the proportion seeing only public providers decreased (19%-15%; P < .01). Coverage levels increased among children seeing all provider types. Coverage levels were higher for children using private providers than those using public providers in 2004 (83% vs 79%; P <.05). Except for White race (coverage was higher among those using private providers vs public providers), coverage levels by demographic variables did not significantly differ between children using only public or only private providers in 2004. Equal emphasis should be placed on the efforts of public providers and private providers to increase coverage among children of all race/ethnicity, income, and residential groups.

Cost-Effectiveness Analysis of a Practice-Based Immunization Education Intervention

To evaluate the cost-effectiveness of academic detailing programs to improve immunization coverage in communities through implementation and evaluation of the Raising Immunizations Thru Education (RITE) program in the Greater Houston area. RITE was a preintervention and postintervention pilot study with randomized intervention and control sites implemented in private practices in pediatrics and family medicine. Changes in self-reported provider behaviors (n = 186) and comparisons of immunization coverage levels between intervention (n = 61) and control (n = 62) practices were evaluated. Intervention costs, computed from the perspective of an agency wanting to replicate the intervention, included direct expenses and time costs, based on time logs and compensation. Sensitivity analysis describes variations in costs. The cost-effectiveness ratio was computed as dollars per additional outcome unit. The RITE intervention improved self-reported provider behavior. The immunization rates in the intervention group increased by 1 per cent, whereas immunization rates in the control group decreased by 2 per cent -3 per cent, but the 3 per cent - 4 per cent difference was not significant. A 1 per cent increase in practice immunization rates costs $424-$550, depending on the up-to-date criteria used and the targeted age group. The costs for 1 additional child with up-to-date immunization status are higher than potential societal savings, as reported in the literature. This intervention does not have a favorable cost-benefit ratio.

Measuring Immunization Coverage among Preschool Children: Past, Present, and Future Opportunities

Control of vaccine-preventable diseases depends on maintaining high levels of immunization coverage. Immunization coverage among preschool children remains suboptimal in some areas and sociodemographic subgroups, as well as for more recently introduced vaccines, leaving susceptible young children vulnerable to complications from vaccine-preventable diseases. This paper reviews approaches historically used to measure immunization coverage among preschool children in the United States. The strengths and weaknesses of various approaches to measuring immunization coverage among preschool children are explored, with emphasis on the current means to measure national immunization coverage-the National Immunization Survey. Methods for measuring immunization coverage among preschool children at local and state levels are also evaluated. Future opportunities and challenges for measuring immunization coverage at the local, state, and national levels are explored.

Measles immunization coverage determined by serology and immunization record from children in two Chicago communities.

We compared the prevalence of measles immunization determined by serology with the prevalence of measles immunization determined by immunization records, and identified factors predictive of measles immunization among a sample of children from two Chicago communities. We collected demographic information and blood specimens from a sample of children aged 12-71 months in two Chicago communities at risk for low measles immunization coverage levels. We collected immunization information from provider records, parent-held records, and the statewide immunization registry. We compared evidence of immunization determined by serology with evidence of immunization from these three sources of immunization records. The sample of children from the two communities had serologic measles immunity levels of 85% and 90%. Significantly fewer children had evidence of immunization by record in both communities (45% and 63%, respectively). Immunization coverage levels determined using immunization records were significantly lower than immunization coverage determined using serology. A fully populated immunization registry used by all immunization providers could prevent the problems of record loss and scatter.

Tetanus toxoid immunization coverage among mothers of below one year of age in difficult-to-reach area of Lagos Metropolis

A retrospective survey of tetanus toxoid immunization coverage was conducted among 196 mothers of children less than one year of age in a difficult-to-reach area of Lagos metropolis. This was to ascertain the status of coverage among the women presumed to have been immunized with minimum of two doses of tetanus toxoid during pregnancy, estimate drop out rates, and investigate reasons for failure to be immunized and determine missed opportunities to get immunized. An interview was conducted by administering questionnaires using WHO cluster form for tetanus toxoid immunization. Recall history and immunization card review were taken as response. The results showed that with card/history criterion, 109 (55.6%) women received first dose of tetanus toxoid (TT), 80 (40.8%) received second dose and 22 (11.2%) received third dose while 87 (44.4%) were not immunized. Using the card criterion that only established valid immunization, 20 (10.2%) women received first dose and 14 (7.2%) received the second dose. With the card criterion analysis, 14 (7.2%) mothers were protected against tetanus and only 4 (2%) babies born of these mothers were protected against tetanus. A decline was observed in compliance with the regimen of vaccination. Thirty three (16.8%) of women studied missed the opportunity of getting vaccinated and 87 (79.8%) of 109 who started vaccination dropped out. Reasons advanced for failure to be immunized included lack of information accounting for 65.85%, lack of motivation was 20.4% and 13.8% as environmental factors. Poverty and lack of health facilities also contributed to the low level of immunization coverage. For TT immunization to improve in the area studied, factors impeding immunization must be addressed. Keywords : tetanus, immunization, coverage African Journal of Clinical and Experimental Microbiology Vol. 6 (3) 2005: 233-237

Immunization Needs of Chronic Liver Disease Patients Seen in Primary Care Versus Specialist Settings

Chronic liver disease patients may benefit from certain vaccines, but their immunization coverage levels have not been widely studied. We examined the serologic and vaccination status of 693 chronic liver disease patients from 37 primary care and specialist centers. Patients in primary care had more often received influenza (47 versus 32%; P < .001) and pneumococcal (39 versus 19%; P < .001) vaccines. Among patients without documented prior exposure, those seeing specialists had more often completed hepatitis A (28 versus 5%; P < .001) and hepatitis B (29 versus 14%; P < .001) vaccination. Coverage was higher in centers with a policy of vaccinating on-site, among non-Hispanic whites, and among patients with hepatitis C and cirrhosis. In summary, most patients were unprotected against one or more vaccine preventable diseases. The higher coverage rates evident in centers vaccinating on-site suggests a breakdown may occur when patients are referred to alternative vaccination venues.

Immunization coverage levels among 19- to 35-month-old children in 4 diverse, medically underserved areas of the United States.

Immunization coverage levels among 19- to 35-month-old children in 4 diverse, medically underserved areas of the United States.

Do Laws Bring Children in Child Care Centers Up to Date for Immunizations?

Pennsylvania state law requires licensed child care centers (CCCs) to document that each enrolled child is up to date (UTD) for routine immunizations within 60 days of enrollment. This study evaluates the law's impact on immunization coverage among children aged <or=59 months who attend CCCs in Philadelphia. Out of Philadelphia's 440 commercial CCCs, 75 were randomly selected. Of these, 9 had closed, 3 did not accept children aged <or=59 months, and 3 refused assessment. For the remaining 60 CCCs, vaccination dates were abstracted from CCC records for all enrolled children <or=59 months. For children not UTD for all vaccines according to CCC records, additional data were sought from Philadelphia's immunization registry, health care providers, and parents. Records of 2847 children were assessed. According to CCC records, information from the immunization registry, vaccination providers, and parents, 71% of children aged 0-18 months, 77% of children 19-35 months, and 84% of children 36-59 months were UTD for their age for diphtheria, tetanus toxoids, and pertussis vaccine; polio; Haemophilus influenzae type b; and measles, mumps, and rubella vaccines. No significant increase in immunization coverage levels was found between the date children enrolled in a CCC and 60 days later. Up to one quarter of children <5 years of age enrolled in Philadelphia's CCCs are not UTD for immunizations, with children 0-18 months of age being most behind in their immunizations. Furthermore, many children do not receive vaccines within 60 days of enrollment. These low coverage levels combined with the potential exposures inherent in group care settings indicate that children in CCCs are at risk for contracting vaccine-preventable diseases.

Racial and Ethnic Disparities in Childhood Immunization Coverage in North Carolina

In 2000 the North Carolina Immunization Branch established the Disparities Core Team to address the issue of disparities in immunization coverage in the state. Since no existing research identified disparities in childhood immunization, the Disparities Core Team undertook a kindergarten survey to determine the existence of disparities. Childhood immunization coverage levels were measured retrospectively by race and ethnicity in North Carolina. Completion of the 4-3-1 series (4 DTaP, 3 Polio and 1 MMR) by 24 months was considered up-to-date. Immunization, demographic, and healthcare information was collected from school records in the fall of 2001 for a sample of kindergarten students. Disparities were found on both state and regional levels. Disparities within regions varied. White children were more likely to be up-to-date by 24 months of age than African American children (OR = 1.60, 95% CI 1.26-2.03), Latino children (OR = 2.24, 95% CI 1.61-3.11), and Asian children (OR = 1.88, 95% CI 1.03-3.4). Discovery of the cause of racial and ethnic disparities requires further study. Implications for interventions to eliminate disparities are discussed.

University Students Immunized and not Immunized for Measles

Objective: To compare students who were immunized or not immunized during the 1997 Simon Fraser University measles outbreak in British Columbia. Methods: Descriptive comparative study using the Health Belief Model as a theoretical framework. A self-administered questionnaire was mailed to a stratified random sample of 400 immunized and 400 non-immunized SFU students. Results: Perceived susceptibility, severity, barriers, cues to action, threat and student age were significantly related to being immunized. Logistic regression analysis achieved an overall correct prediction rate of 84.7% by including the contribution of the four variables of susceptibility, barriers, cues to action, and health motivation. Content analysis of the non-immunized students’ descriptions of what it would have taken for them to be immunized indicated the influence of these four variables. Discussion: The Immunization Health Belief Model Scale is a valuable tool for ascertaining attitudes and beliefs relating to immunization decision-making. Interventions targeted to significant beliefs may increase immunization coverage levels and result in improved disease prevention.

Children, Vaccines, and Risks

Modern vaccines have had a major impact on the occurrence of a number of diseases of childhood, with reductions of >95% in reported incidence. Immunization coverage levels have never been higher. There is an extensive process for risk assessment and risk management relating to vaccines although there is still room for improvement. A major shortcoming is effective risk communication—we simply do not do a very good job of dealing with risk perception ( “outrage”). Providers need to learn how to listen well and communicate effectively with parents. We must learn to talk with people, not to them or at them.

Exploring childhood immunization uptake with First Nations mothers in north-western Ontario, Canada.

Childhood immunization is an important component of preventive health care for young children. Successful control of vaccine-preventable diseases depends on high levels of immunization coverage. Immunization statistics show that on-reserve First Nations (Native Indian) children have lower vaccination coverage than children in the general Canadian population. There has been little research, however, conducted with First Nations populations on this topic. This study explored First Nations parents' beliefs about childhood immunizations and examined factors influencing immunization uptake. This study used a qualitative descriptive design to explore the issue of childhood immunization uptake. Twenty-eight mothers from two First Nations communities in north-western Ontario, Canada, were interviewed about their perceptions of childhood immunizations and vaccine-preventable diseases. The interviews were transcribed and content analysis was used to examine the data. Data analysis revealed the following six themes: (1) the fear of disease; (2) the efficacy of immunizations; (3) the immunization experience; (4) the consequences of immunization; (5) interactions with health professionals; and (6) barriers to immunizations. Participants were motivated to seek immunizations for their children by a fear of vaccine preventable diseases. A small proportion of mothers, however, questioned the effectiveness of vaccines in preventing disease. Traumatic immunization experiences, vaccine side-effects and sequelae, negative interactions with health professionals, and barriers such as time constraints and childhood illnesses all served as deterrents to immunization. The research outcomes highlight the varied beliefs of First Nations parents about childhood immunizations and the numerous factors that both positively and negatively influence immunization uptake. Further research is needed to explore the issue of childhood immunizations in First Nations communities and to determine strategies to improve uptake.

Visiting multiple sites for immunization and vaccine coverage levels of preschool children in 3 urban clinics: potential indicator of record scatter?

Record scatter is a clinic-level impediment to accurately reporting immunization coverage levels but may be attributed to certain patient characteristics. We determine the association between visiting multiple sites for immunization and underimmunization among urban clinic patients. After collecting immunization histories for patients aged 3-35 months, caregivers were surveyed by telephone. 159/483 caregivers (32.9%) were interviewed. Visiting > 2 sites for immunizations was associated with underimmunization, adjusted Odds Ratio (95% Confidence Interval)=2.7 (1.2-6.5). An interruption in health insurance showed a trend toward association with visiting > or = 2 sites. Our results support the need for working registries, clinic outreach, and continued evaluation of both.

Impact of multiple injections on immunization rates among vulnerable children

Background: In 1997, the Advisory Committee on Immunization Practices (ACIP) recommended a switch from oral polio vaccine (OPV) to inactivated polio vaccine (IPV) for the first two infant doses. The ACIP also recommended use of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) for infants. These recommendations resulted in two additional injections at the 2- and 4-month immunization visits. This study evaluates the implementation of new IPV and DTaP immunization recommendations and their impact on immunization coverage levels. Methods: Immunization coverage was assessed in public clinics in three urban areas before and after the recommendations. One pre- and three post-recommendation cohorts were followed to 12 months of age. Results: Almost all (≥88%) infants in the pre-recommendation cohort received OPV, DTP, and only one or two injections. Almost all (≥78%) infants in the post-recommendation cohorts received IPV, DTaP, and three or four injections. The percentage of infants in the post-recommendation cohorts up-to-date for immunizations at 12 months of age was slightly higher than those in the pre-recommendation cohort. Conclusions: Providers rapidly switched from OPV and DTP to IPV and DTaP. Coverage at 12 months of age was higher among IPV/DTaP recipients than among OPV/DTP recipients. Provider and parent acceptance of four injections at a visit was high. The recent pneumococcal conjugate vaccine recommendations potentially add a fifth injection at 2 and 4 months of age. Acceptance or rejection of five injections by providers and parents needs early assessment.

Moderate immunization coverage levels in East Delhi: implications for disease control programmes and introduction of new vaccines.

A vaccination coverage survey conducted in East Delhi in September 1999 showed that only 58.6 per cent of the children aged 12-23 months had received the full course of the vaccines recommended under the national immunization programme. Coverage with the third dose of DTP and oral polio vaccines was around 71 per cent, and with BCG and measles vaccines was 83 and 59 per cent, respectively. Drop-out rates between DTP1 and DTP3 and between DTP1 and measles immunization were 13.8 and 28.7 per cent, respectively. Nine per cent of the children had not received a single dose of any vaccine. The main reason for failure to immunize was lack of information. There was a marginal increase in DTP3 and OPV3 immunization coverage levels as recorded through a previous survey in 1996, a drop in coverage with measles vaccine from 64.3 to 59 per cent, and a significant increase in tetanus toxoid immunization coverage of pregnant women from 79.4 to 93 per cent. The percentage of children who had not received any vaccine declined from 13 to 9 per cent in the period between the two surveys. Coverage with hepatitis B vaccine at 14 per cent was only marginally higher than the baseline rate of 9 per cent before the vaccine was made available, free of cost, through government and municipal corporation health facilities.

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.