[Does a modified vaccination schedule protect better against measles?]

OBJECTIVE

To assess the value of an alternative vaccination programme (VP) with Mumps-Measles-Rubella (MMR) vaccine at the ages of 12 and 15 months compared with the standard VP (MMR at the ages of 14-15 months and 9 years).

DESIGN

Cross-sectional study.

SETTING

The area of activity of the 'Lek and Merwede' Extramural Health Care Department.

METHOD

Data from general practitioners (GPs) and from an inquiry among parents of 873 children born in a 1.5 year period (randomly taken among 4500 children) and given the alternative MMR VP, were used. The inquiry took place during a measles epidemic in 1993. A non-response study was also executed among the parents.

RESULTS

The response of the GPs was low (14 cases reported by 8 out of 90 GPs). Eighty-two per cent of the parents responded. There was no correlation between (non-)response and the alternative VP. The vaccination was effective and no significant differences between standard and alternative VP were found.

CONCLUSION

Vaccination protects against measles. An alternative VP could theoretically be more effective, but because of the excellent results of the standard VP differences could not be detected.

The elimination of indigenous measles, mumps, and rubella from Finland by a 12-year, two-dose vaccination program

BACKGROUND

In the 1970s measles, mumps, and rubella were rampant in Finland, and rates of immunization were inadequate. In 1982 a comprehensive national vaccination program began in which two doses of a combined live-virus vaccine were used.

METHODS

Public health nurses at 1036 child health centers administered the vaccine to children at 14 to 18 months of age and again at 6 years, and also to selected groups of older children and young adults. Vaccination was voluntary and free of charge. In follow-up studies, we focused on rates of vaccination, reasons for noncompliance, adverse reactions, immunogenicity, persistence of antibody, and incidence of the three diseases. Since 1987, paired serum samples have been collected from all patients with suspected cases of measles, mumps, or rubella.

RESULTS

Over a period of 12 years, 1.5 million of the 5 million people in Finland were vaccinated. Coverage now exceeds 95 percent. The vaccine was efficient and safe, even in those with a history of severe allergy. No deaths or persistent sequelae were attributable to vaccination. The most frequent complication requiring hospitalization was acute thrombocytopenic purpura, which occurred at a rate of 3.3 per 100,000 vaccinated persons. The 99 percent decrease in the incidence of the three diseases was accompanied by an increasing rate of false positive clinical diagnoses. In 655 vaccinated patients with clinically diagnosed disease, serologic studies confirmed the presence of measles in only 0.8 percent, mumps in 2.0 percent, and rubella in 1.2 percent. The few localized outbreaks were confined to patients in the partially vaccinated age groups. There are now fewer than 30 sporadic cases of each of the three diseases per year, and those are probably imported.

CONCLUSIONS

Over a 12-year period, an immunization program using two doses of combined live-virus vaccine has eliminated indigenous measles, mumps, and rubella from Finland. Serologic studies show that most reported sporadic cases are now due to other causes, but a continued high rate of vaccination coverage is essential to prevent outbreaks resulting from exposure to imported disease.

Risk factors for delayed immunization among children in an HMO

OBJECTIVES

Improving the timely delivery of childhood immunizations has become a national imperative. This study aimed to identify nonfinancial predictors of delayed immunization among patients with good financial access to preventive care.

METHODS

This prospective cohort study used telephone interviews and a computerized immunization tracking system to evaluate 13-month-old children (n = 530) in a regional group-model health maintenance organization.

RESULTS

More than one third of parents interviewed did not know when the next immunization was due. Thirteen percent were late for the measles-mumps-rubella immunization, recommended at 15 months of age, by 90 days or more. Independent predictors of delayed immunization included having a larger number of children (odds ratio [OR] = 1.4, P < .01), not having a regular doctor (OR = 2.9, P < .05), not knowing when the shot was due (OR = 2.0, P < .01), and not worrying about the risks of shots (OR = 1.4, P < .05).

CONCLUSIONS

Financial access alone does not guarantee timely childhood immunization. In managed care settings, which may cover increasing numbers of children under health care reform, interventions are needed to better inform parents of when immunizations are due.

Intent to immunize among pediatric and family medicine residents

OBJECTIVE

To determine whether contraindications to immunization are inappropriately broadened for children with a fever or a neurologic condition.

PARTICIPANTS

Pediatric and family medicine residents (N = 52 and 23, respectively) at the University of Rochester (NY).

DESIGN

Cross-sectional survey. Residents rated how likely they would be to administer a diphtheria-tetanus-pertussis or measles-mumps-rubella vaccine in 17 clinical scenarios according to a rating scale ranging from 1 (never) to 5 (always). For all scenarios, the immunization was recommended by the American Academy of Pediatrics or the Immunization Practices Advisory Committee.

RESULTS

In only five and three of 17 scenarios would 90% or more of the pediatric residents and family medicine residents, respectively, have administered an immunization. For diphtheria-tetanus-pertussis vaccine, pediatric residents reported a lower likelihood of vaccinating a 2-month-old child with a low fever (temperature, 38.1 degrees C) than an afebrile child (mean score, 3.0 vs 4.7; P < .01). A 2-year-old child with idiopathic epilepsy, a 2-month-old child with intraventricular hemorrhage, and a 2-month-old child who had a parent with a seizure disorder each had a lower reported likelihood to be vaccinated than a same-aged child without a neurologic condition (2.8 vs 4.5; 4.1 vs 4.7; and 4.3 vs 4.7, respectively; each P < .01). For measles-mumps-rubella, pediatric residents reported a lower likelihood of vaccinating a 15-month-old child with a low fever than an afebrile child (4.2 vs 4.9; P < .01). A child with a progressive neurologic disease had a lower reported likelihood to be vaccinated than a child without a neurologic condition (3.5 vs 4.9; P < .01).

CONCLUSIONS

Residents reported a lower likelihood of immunizing children with a fever or neurologic condition. Such practice styles may contribute to underimmunization. Residents need to be educated regarding which medical conditions contraindicate an immunization.

Potential impact on vaccination coverage levels by administering vaccines simultaneously and reducing dropout rates

BACKGROUND

Retrospective immunization coverage surveys conducted during 1991 and 1992 demonstrated that coverage levels for the routine childhood vaccines by 24 months of age in selected urban areas of the United States ranged from 10% to 52%, far below the US Public Health Service goal of 90%. Therefore, appropriate programmatic changes must be identified and incorporated.

METHODS

We analyzed coverage survey data collected from 21 sites to measure the potential impact on coverage levels of implementing selected changes in vaccination practices. In a multistaged cluster survey design, school health records of kindergarten or first-grade students were randomly selected and dates of vaccination assessed. We evaluated changes in the vaccination practices, such as eliminating missed opportunities for simultaneous administration of vaccines and ensuring that children initiated the vaccination series on time (ie, by 3 months of age). We then calculated potential increases in coverage levels for a best-case scenario.

RESULTS

From 77% to 96% of all children in the 21 sites had received at least one vaccination by their first birthday. Children were 2.3 to 17 times more likely to be up to date on their vaccinations by 24 months of age if they were up to date at 3 months of age. Each child had many opportunities for the simultaneous administration of diphtheria and tetanus toxoids and pertussis (DTP) vaccine, oral polio vaccine (OPV), and measles-mumps-rubella (MMR) vaccine that, if used appropriately, could have potentially raised coverage levels by 12% to 22% (median, 17%). The highest coverage levels could have been attained if all children had started the series on time and if advantage had been taken of all opportunities for simultaneous vaccination. Coverage levels for four doses of DTP vaccine, three doses of OPV, and one dose of MMR vaccine would have increased from a baseline of 10% to 52% to levels of 54% to 83%.

CONCLUSIONS

Although the majority of children received a vaccination by their first birthday, the coverage level at 24 months of age was low. Tracking systems are needed to ensure that children do not drop out of the system once they have begun the vaccination series. In addition, all children who are late in beginning their vaccination series are at increased risk of not completing the recommended vaccination series on time, and these children need intensive follow-up and recall efforts. Also, providers need to administer all needed vaccines simultaneously.

[Mumps--occupational exposure and aspects of epidemiologic susceptibility]

1041 persons working in the university hospital of Freiburg, Germany, were tested for mumps antibodies. The first part of the investigation was conducted between 1986 and 1988, the second one in 1992. Significant decrease in seroprevalence between study I (67% immune) and study II (63% immune) was found. Average immunity of paediatric nurses was significantly higher (76%) than that of non-exposed persons (59.7%). 195 persons were vaccinated (live vaccine) and 84.6% seroconverted.

Responses to measles immunization in children infected with human immunodeficiency virus

The responses to measles immunization administered between 6 and 12 months and after 12 months were compared in children with and without human immunodeficiency virus infection. No difference in response was found when primary measles immunization was administered between 6 and 12 months; however, children with human immunodeficiency virus infection had a significantly poorer response when immunization was given after 12 months. Early measles immunization should be considered in children with human immunodeficiency virus infection.

Measles immunization of 2-year-olds in a rural southern state

OBJECTIVE

To assess the measles vaccine coverage of 2-year-old children living in Mississippi during the national measles epidemic of 1989 and 1990.

DESIGN

Survey of 2-year-olds randomly selected from the 1987 birth cohort. The status of measles-mumps-rubella (MMR) vaccination was determined by medical record reviews and family contacts.

SETTING

A predominantly rural state in the southeastern United States with a large black minority population (35%) and a low per capital income ($9827 to $12,899). Approximately 80% of MMR immunizations are given by public health service nurses working in nine health districts.

SUBJECTS

A total of 2450 preschool-aged children representing 6% of the 1987 birth cohort (n = 41,279). Three hundred forty-one children were considered ineligible, leaving 2109 in the final sample.

MAIN OUTCOME MEASURES

Confirmed vaccination by the age of 2 years. Rates of immunization were calculated for the entire state, its health districts, and subgroups based on population density, per capita income, type of clinic visited, and race.

RESULTS

The statewide immunization rate was 87% (95% confidence interval, 86% to 88%). Among the nine health districts, rates varied from 79% to 97% (median, 88%). They were similar for white and black children in each health district and within the state as a whole. The level of vaccine coverage was significantly higher in districts with lower population densities (89% vs 85%, P = .02) and in those with higher per capita incomes (89% vs 86%, P = .03). There were four minor outbreaks of measles during 1989 and 1990; half of the cases occurred in unimmunized children too young to receive the MMR vaccine.

CONCLUSION

A high rate of measles immunization is attainable among 2-year-olds living in a rural state with a large black minority population and limited economic resources.

Vaccination coverage of 2-year-old children--United States, 1992-1993

The principal goal of the Childhood Immunization Initiative (CII) is to increase, by 1996, vaccination levels for 2-year-old children to at least 90% for the most critical doses in the vaccination series (i.e., one dose of measles-mumps-rubella vaccine [MMR] and at least three doses each of diphtheria and tetanus toxoids and pertussis vaccine [DTP], oral poliovirus vaccine [OPV], and Haemophilus influenzae type b vaccine [Hib]) and to at least 70% for at least three doses of hepatitis B vaccine (Hep B). Since 1991, annual national estimates of vaccination coverage levels of preschool-aged children have been available through the National Health Interview Survey (NHIS) conducted by CDC. This report presents vaccination coverage levels of children aged 19-35 months for 1992 and provisional estimates of vaccination coverage for the combined first and second quarters of 1993 (Table 1).

Immunization coverage in a population-based sample of Maryland children

OBJECTIVE

To describe the vaccination coverage of a population-based sample of Maryland children.

DESIGN

Historical cohort study using stratified cluster sampling. Strata were formed from five state regions and public and private schools within each region.

SETTING

Random sample of elementary schools in Maryland.

SUBJECTS

Immunization records were obtained for a randomly selected cohort of 1938 first-grade children in Maryland.

OUTCOME MEASURES

Age of completion of recommended childhood vaccines and proportion of vaccines given simultaneously.

RESULTS

By first grade, 95.2% of the sample of Maryland children were documented to have received at least four doses of the diphtheria and tetanus toxoids and pertussis (DTP) vaccine, three doses of oral poliovirus (OPV) vaccine, and one dose of measles-mumps-rubella (MMR) vaccine. However, only 54.8% of children surveyed had achieved this level of immunization by 24 months of age. For children whose immunizations were up to date on their first birthday (78.7% of children surveyed), vaccine providers failed to administer one dose of DTP, OPV, and MMR vaccines to 30% of these children during the second year of life. Only 16.2% (n = 313) of children sampled received an MMR vaccination simultaneously with any dose of DTP or OPV vaccine.

CONCLUSIONS

This study shows that while immunization levels are very high at school entry, there are serious delays in vaccine administration before school entry. These delays are observed regardless of whether children are in public or private schools or attend school in an urban, suburban, or rural area. Physicians and health care providers could play an important role in age-appropriate vaccination by administering vaccines simultaneously.

Low vaccination levels of US preschool and school-age children. Retrospective assessments of vaccination coverage, 1991-1992

OBJECTIVE

To obtain estimates on (1) the percentage of children who were up-to-date on the recommended childhood vaccination series, (2) the percentage of children who were age-appropriately immunized, and (3) coverage levels by individual vaccines.

DESIGN

Vaccination levels were estimated by conducting retrospective immunization coverage surveys of the school health records of children entering kindergarten or first grade in the 1990-1991 or 1991-1992 school year. A multistage cluster survey design was used.

SETTING

Survey sites were selected from among the 60 largest urban areas in the United States. One small city and one rural area were selected for comparison.

RESULTS

By their second birthday, 11% to 58% (median, 44%) of the children were fully vaccinated. Stricter measurement criteria lowered coverage levels further. Completed series levels at school entry were 71% to 96% (median, 87%).

CONCLUSIONS

Vaccination levels at the second birthday were far below the goal for the year 2000. All health providers need to administer vaccines according to the recommended schedule.

Measles--Puerto Rico, 1993, and the measles elimination program

In the Commonwealth of Puerto Rico, a resurgence of measles peaked in 1990 when 1805 cases (51.3 cases per 100,000 population) and 12 measles-related deaths were reported. This report summarizes the persistence of measles transmission in Puerto Rico in 1993 and describes the Puerto Rico Measles Elimination Program.

Quality standard for assurance of measles immunity among health care workers. The Infectious Diseases Society of America

OBJECTIVE

The objective of this quality standard is to prevent nosocomial transmission of measles by assuring universal measles-mumps-rubella (MMR) vaccination of all health care workers who lack immunity to measles. Although the primary emphasis is on health care workers in hospitals, those at other sites, such as clinics, nursing homes, and schools, are also included. It will be the responsibility of designated individuals at these institutions to implement the standard.

OPTIONS

We considered advocating the use of measles vaccine rather than MMR but chose the latter because it also protects against mumps and rubella and because it is more readily available.

OUTCOMES

The desired outcome is a reduction in the nosocomial transmission of measles.

EVIDENCE

Although direct comparative studies are lacking, nosocomial outbreaks of measles have been reported (as recently as 1992) in institutions where measles immunization of nonimmune health care workers is not universal, whereas such outbreaks have not been reported in institutions with universal immunization. VALUES AND VALIDATION: We consulted more than 50 infectious-disease experts in epidemiology, government, medicine, nursing, obstetrics and gynecology, pediatrics, and surgery. In light of disagreement regarding the implementation of the standard, we used group discussions to reach a consensus.

BENEFITS, HARMS, AND COSTS

The consequences of the transmission of measles (and of mumps and rubella) in a health care institution include not only the morbidity and mortality attributable to the disease, but also the significant cost of evaluating and containing an outbreak and the serious disruption of regular hospital routines when control measures are instituted. The potential harm to health care workers after the implementation of the standard consists of untoward effects of MMR vaccine, although the reactions of vaccines should be minimal with adherence to recommended vaccination procedures. Implementation of the standard should entail no expense to health care workers; the precise cost to institutions is unknown, but the expense would be mitigated by prevention of measles outbreaks.

RECOMMENDATIONS

We recommend MMR vaccination of all health care workers who lack immunity to measles.

SPONSORS

The Quality Standards Subcommittee of the Clinical Affairs Committee of the Infectious Diseases Society of America (IDSA) developed the standard. The subcommittee was composed of representatives of the IDSA (Drs. Gross and McGowan), the Society for Hospital Epidemiology of America (Dr. Wenzel), the Surgical Infection Society (Dr. Dellinger), the Pediatric Infectious Diseases Society (Dr. Krause), the Centers for Disease Control and Prevention (Dr. Martone), the Obstetrics and Gynecology Infectious Diseases Society (Dr. Sweet), and the Association of Practitioners of Infection Control (Ms. Barrett). Funding was provided by the IDSA and the other cooperating organizations. The standard is endorsed by the IDSA.