Risk factors for delay in age-appropriate vaccination.
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OBJECTIVE: To estimate the risk factors of children experiencing delay in age-appropriate vaccination using a nationally representative population of children, and to compare risk factors for vaccination delay with those based on up-to-date vaccination status models. METHODS: The authors compared predictors of delay in age-appropriate vaccination with those for children who were not up-to-date, using a nationally representative sample of children from five years of pooled data (1992-1996) from the National Health Interview Survey (NHIS) Immunization Supplement. Duration of delay was calculated for the DTP4, Polio3, MMR1 doses and 4:3:1 series using age-appropriate vaccination standards; up-to-date status (i.e., whether or not a dose was received) was also determined. Adjusted odds ratios were estimated using multivariate logistic regression for models of vaccination delay and up-to-date vaccination status. RESULTS: Absence of a two-parent household, large family size, parental education, Medicaid enrollment, absence of a usual provider, no insurance coverage, and households without a telephone were significantly related to increased odds of a child experiencing vaccination delay (p < or = 0.05). CONCLUSIONS: Many of the risk factors observed in models of vaccination delay were not found to be significant in risk models based upon up-to-date status. Consequently, risk models of delays in age-appropriate vaccination may foster identification of children at increased risk for inadequate vaccination. Populations at increased risk of inadequate vaccination can be more clearly identified through risk models of delays in age-appropriate vaccination. (+info)
Vaccine coverage levels after implementation of a middle school vaccination requirement, Florida, 1997-2000.
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OBJECTIVE: Little information is available about the effectiveness of school entry vaccination requirements at the middle school level. This study examined coverage levels among students entering seventh grade in Florida following implementation of a school entry vaccination requirement in 1997. METHODS: The authors analyzed county-specific vaccination coverage levels (three doses of hepatitis B vaccine, a second dose of measles, mumps, and rubella [MMR] vaccine, and a booster dose of tetanus and diphtheria toxoids [Td]) among students entering public and private schools in Florida from 1997 through 2000. In 1998, a survey of all county health departments was conducted, and the resulting data were linked to county-specific vaccination rates. RESULTS: During the 1997-1998 school year, the first year the requirement went into effect, at school entry 121,219 seventh-grade students (61.8%) were fully vaccinated, 72,275 seventh grade students (36.9%) lacked one or more doses of vaccine but were considered in process, 1,817 were non-compliant (0.9%), and 763 had medical or religious exemptions (0.4%). In the 2000-2001 school year, the proportions of students reported fully vaccinated at school entry had increased to 66%. Most of this change was related to an increase in hepatitis B coverage. There was a significant inverse relationship between the proportion of students fully vaccinated and the size of the county's seventh grade population. CONCLUSIONS: The seventh grade vaccination entry requirement was associated with sustained high levels of vaccination coverage. Passing a school entry vaccination requirement appears may be sufficient to increase coverage, but other strategies may be required to achieve full immunization of middle school students. (+info)
Humoral and cell-mediated immune responses to an early 2-dose measles vaccination regimen in the United States.
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BACKGROUND: Shifts in peak measles incidence to children <12 months old and the associated high mortality support the study of an early 2-dose measles vaccine regimen. METHODS: Fifty-five infants were vaccinated with measles vaccine at age 6 (n=32) or 9 (n=23) months, followed by measles-mumps-rubella (MMR)-II vaccine at age 12 months. A control group received MMR-II only at age 12 months. Measles-specific humoral and cell-mediated immunity were evaluated before, 12 weeks after measles immunization, and 24 weeks after MMR-II. RESULTS: Measles-specific T cell proliferation after both doses of vaccine was equivalent, regardless of age or the presence of passive antibodies. Seroconversion rates, geometric mean titers, and the percentage of infants with antibody titers >120 mIU after the first measles vaccine were lower in infants vaccinated at age 6 months, regardless of the presence of passive antibodies, but measles humoral responses increased after the administration of MMR-II vaccine in children initially vaccinated at age 6 or 9 months. CONCLUSION: Measles vaccination elicits T cell responses in infants as young as 6 months old, which may prime the humoral response to the second dose. Initiating measles vaccination as an early 2-dose regimen results in an immunologic response that is likely to have clinical benefits in developed and developing countries. (+info)
Managing controversy through consultation: a qualitative study of communication and trust around MMR vaccination decisions.
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BACKGROUND: Controversy over the measles, mumps, and rubella (MMR) vaccine has reduced uptake, raising concerns of a future disease epidemic. AIMS: To explore parents' accounts of decision making relating to the MMR vaccine controversy, identifying uptake determinants and education needs. DESIGN OF STUDY: Qualitative interviews analysed using the 'framework' approach. SETTING: Five general practices in the Leeds area, 2002-2003. METHOD: Sixty-nine interviews conducted with parents of children aged between 4 and 5 years, and 12 interviews with primary care practitioners, managers and immunisation coordinators serving participating sites. Participants were interviewed one-to-one in a place of their choice. RESULTS: The vaccination decision is primarily a function of parental assessments of the relative acceptability and likelihood of possible outcomes. For most parents the evidence of science and medicine plays little role in the decision. Although local general practitioners and health visitors are trusted information sources, the influence of primary care providers on the vaccination decision is limited by concerns over consultation legitimacy, discussion opportunity, and perceptions of financial and political partiality. Parents and practitioners identify a need for new approaches to support decisions and learning when faced with this and similar healthcare controversies. These include new collaborative approaches to information exchange designed to transform rather than supplant existing parent knowledge as part of an ongoing learning process. CONCLUSION: The study identified new ways in which parents and practitioners need to be supported in order to increase understanding of medical science and secure more informed decisions in the face of health controversy. (+info)
Predicting uptake of MMR vaccination: a prospective questionnaire study.
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BACKGROUND: Recent years have seen a decline in the uptake of the measles, mumps, and rubella (MMR) vaccination. AIM: To describe parents' beliefs about the MMR vaccination and to explore the best predictors of uptake by the age of 2 years. DESIGN OF STUDY: Prospective questionnaire study. SETTING: Brighton and Hove area of East Sussex. METHOD: Five hundred and eleven parents (response rate = 56.9%) completed a baseline questionnaire regarding their profile characteristics, beliefs about MMR and previous vaccination history prior to receiving a letter to attend for their child's vaccination. Attendance data was collected at follow-up by the age of 2 years. RESULTS: The majority of parents believed that measles, mumps and rubella were serious illnesses and stated that they would feel guilty about any adverse consequences of their decision about vaccination. Many responders were ambivalent about the benefit of vaccinations and were unsure whether to trust either the medical profession or the media. Uptake of MMR vaccination at follow-up was related to previous uptake for vaccination, increased faith in the medical profession, increased faith in the media, and a lower belief that vaccination is unhealthy and can harm the immune system. CONCLUSION: Many parents hold mixed beliefs about the MMR vaccination and the doctors who administer it. Uptake relates to past vaccination and more positive beliefs. (+info)
A middle school immunization law rapidly and substantially increases immunization coverage among adolescents.
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OBJECTIVES: This study assessed the effectiveness of a middle school vaccination requirement for raising second-dose measles, mumps, and rubella vaccine and hepatitis B vaccine coverage among adolescents. METHODS: Random-digit-dialed telephone surveys were conducted before (1998) and after (1999) the implementation of a vaccination requirement for entry into the seventh grade in San Diego, Calif. RESULTS: Vaccination coverage was higher among children subject to the vaccination requirement (seventh-grade students; 60%) than among fifth- and sixth-grade students 1 year before the requirement (13%, P <.001), and 8th- through 12th-grade students not subject to the requirement (27%, P <.0001). CONCLUSIONS: Middle school-entry vaccination requirements can rapidly and substantially raise vaccination coverage among students subject to the law. (+info)
Vaccine risk perception among reporters of autism after vaccination: vaccine adverse event reporting system 1990-2001.
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OBJECTIVES: We investigated vaccine risk perception among reporters of autism to the Vaccine Adverse Event Reporting System (VAERS). METHODS: We conducted structured interviews with 124 parents who reported autism and related disorders to VAERS from 1990 to 2001 and compared results with those of a published survey of parents in the general population. RESULTS: Respondents perceived vaccine-preventable diseases as less serious than did other parents. Only 15% of respondents deemed immunization extremely important for children's health; two thirds had withheld vaccines from their children. CONCLUSIONS: Views of parents who believe vaccines injured their children differ significantly from those of the general population regarding the benefits of immunization. Understanding the factors that shape this perspective can improve communication among vaccine providers, policymakers, and parents/patients. (+info)
Assessment of humoral immunity to poliomyelitis, tetanus, hepatitis B, measles, rubella, and mumps in children after chemotherapy.
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BACKGROUND: To evaluate the effect of chemotherapy on humoral immunity to vaccine-preventable disease, the authors investigated the persistence of protective antibody titers in a group of patients who were alive and well after they were treated for pediatric malignancies. METHODS: Serum antibody levels were evaluated for polio, tetanus, hepatitis B, rubella, mumps, and measles in 192 children. The terms lack of immunity and loss of immunity, respectively, were used to describe the absence of immunity in patients who were tested only after chemotherapy and in patients who were tested both before and after chemotherapy and determined to have immunity before chemotherapy. RESULTS: Overall, the absence of a protective serum antibody titer for hepatitis B, measles, mumps, rubella, tetanus, and polio was detected in 46%, 25%, 26%, 24%, 14%, and 7% of patients, respectively. On univariate analysis, loss of antibodies against rubella, mumps, and tetanus was associated significantly with younger age (P < 0.001, P = 0.02, and P = 0.001, respectively), and loss of antibodies against measles was significantly associated with younger age and female gender (P = 0.0003 and P = 0.008, respectively). The administration of 59 booster vaccinations to 51 patients who had lost > or = 1 protective antibody titer resulted in an overall response rate of 93%. CONCLUSIONS: Chemotherapy induced different rates of loss of protective antibody titers depending on the type of vaccination administered. This finding may be responsible for the failure of vaccination programs for patients who have undergone chemotherapy. The administration of a booster dose after the completion of chemotherapy is a simple and cost-effective way to restore humoral immunity against most vaccine-preventable diseases. (+info)