Measles outbreak in a highly vaccinated population, San Diego, 2008: role of the intentionally undervaccinated.

Objective: In January 2008, an intentionally unvaccinated 7-year-old boy who was unknowingly infected with measles returned from Switzerland, resulting in the largest outbreak in San Diego, California, since 1991. We investigated the outbreak with the objective of understanding the effect of intentional undervaccination on measles transmission and its potential threat to measles elimination.

Methods: We mapped vaccination-refusal rates according to school and school district, analyzed measles-transmission patterns, used discussion groups and network surveys to examine beliefs of parents who decline vaccination, and evaluated containment costs.

Mumps resurgences in the United States: A historical perspective on unexpected elements.

In 2006 the United States experienced the largest nationwide mumps epidemic in 20 years, primarily affecting college dormitory residents. Unexpected elements of the outbreak included very abrupt time course (75% of cases occurred within 90 days), geographic focality (85% of cases occurred in eight rural Midwestern states), rapid upward and downward shift in peak age-specific attack rate (5-9-year olds to 18-24-year olds, then back), and two-dose vaccine failure (63% of case-patients had received two doses). To construct a historical context in which to understand the recent outbreak, we reviewed US mumps surveillance data, vaccination coverage estimates, and relevant peer-reviewed literature for the period 1917-2008.

Persistence of rubella antibodies after 2 doses of measles-mumps-rubella vaccine.

Background: Since 1990, most schoolchildren in the United States have received a second dose of measles-mumps-rubella vaccine (MMR2) at kindergarten entry. Elimination of endemic rubella virus circulation in the United States was declared in 2004. The objective of the current study was to evaluate the short- and long-term rubella immunogenicity of MMR2.

Persistence of mumps antibodies after 2 doses of measles-mumps-rubella vaccine.

Background: Since 1990, most US schoolchildren have received a second dose of measles-mumps-rubella vaccine (MMR2) at kindergarten entry. The objective of the present study was to evaluate the short- and long-term mumps immunogenicity of MMR2.

Methods: At enrollment in 1994-1995, children (n=308) in a rural Wisconsin health maintenance organization received MMR2 at age 4-6 years.

Mumps vaccination coverage and vaccine effectiveness in a large outbreak among college students--Iowa, 2006.

Following implementation of a routine childhood two-dose measles-mumps-rubella vaccination strategy, mumps disease levels dropped dramatically in the US and an elimination goal was set for 2010. However, a 2006 epidemic involved >5700 cases nationwide, with many reported among fully vaccinated college students. In an outbreak in two Iowa colleges, we investigated: (1) vaccination coverage using electronic records verified by provider records and (2) vaccine effectiveness assessed by comparison of dose-specific attack rates.

Persistence of measles antibodies after 2 doses of measles vaccine in a postelimination environment.

Objective: To evaluate the persistence of measles antibodies after 2 doses of measles vaccine in a setting where exposure to wild-type measles was unlikely. Measles was declared eliminated from the United States in 2000, an achievement attributed to effective implementation of a routine 2-dose vaccination policy. Some have questioned whether measles transmission could resume if immunity wanes in the absence of boosting from wild-type measles.

Evaluation of potentially common adverse events associated with the first and second doses of measles-mumps-rubella vaccine.

Background/objectives: In 1989, the American Academy of Pediatrics and the Advisory Committee on Immunization Practices recommended that school children receive 2 doses of measles-mumps-rubella vaccine. With measles and rubella eliminated from the United States, measles-mumps-rubella vaccine adverse events have come under scrutiny, but no study has compared the reactogenicity of the first (measles-mumps-rubella vaccine dose 1) and second (measles-mumps-rubella vaccine dose 2) doses at the most common ages of administration in the United States.

Methods: From a health maintenance organization, 3 groups of children were recruited: (1) toddlers aged 12 to 24 months receiving measles-mumps-rubella vaccine dose 1; (2) kindergartners aged 4 to 6 years receiving measles-mumps-rubella vaccine dose 2; and (3) middle schoolers aged 10 to 12 years receiving measles-mumps-rubella vaccine dose 2.

Implications of a 2005 measles outbreak in Indiana for sustained elimination of measles in the United States.

Background: Measles was declared eliminated from the United States in 2000 but remains endemic worldwide. In 2005, a 17-year-old unvaccinated girl who was incubating measles returned from Romania, creating the largest documented outbreak of measles in the United States since 1996.

Methods: We conducted a case-series investigation, molecular typing of viral isolates, surveys of rates of vaccination coverage, interviews regarding attitudes toward vaccination, and cost surveys.

Individually significant risk factors do not provide an accurate clinical prediction rule for infant underimmunization in one disadvantaged urban area.

Objective: To define a clinical prediction rule for underimmunization in children of low socioeconomic status.

Methods: We assessed a cohort of 1160 infants born from July 1998 through June 1999 at an urban safety net hospital that received primary care at 4 community health centers. The main outcome measure was up-to-date status with the 3:2:2:2 infant vaccine series at 12 months of age.

Measles transmission and vaccine effectiveness during a large outbreak on a densely populated island: implications for vaccination policy.

Background: The Republic of the Marshall Islands (RMI) is a South Pacific nation freely associated with the United States. In 2003, the RMI experienced the largest measles outbreak within the United States or its associated areas for more than a decade, although the reported coverage of 1-dose measles-mumps-rubella (MMR) vaccine was 80%-93%. The outbreak ended only after vaccination of >35,000 persons among a population of 51,000.

The cost of containing one case of measles: the economic impact on the public health infrastructure--Iowa, 2004.

Background: In February 2004, students from a college in Iowa, with a high proportion of nonmedical exemptions to vaccination, traveled to India; one fourth of the students contracted measles while there. One exposed, susceptible student returned home during his infectious period, necessitating 2 months of containment efforts in Iowa.

Objective: The objective of this study was to measure the direct costs of measles containment from a public health system perspective.

Health-state valuations for pertussis: methods for valuing short-term health states.

Background: The incidence of reported adolescent and adult pertussis continues to rise in the United States. Acellular pertussis vaccines for adolescents and adults have been developed and may be available soon for use in the U.S.

Ensuring preparedness for potential poliomyelitis outbreaks: Recommendations for the US poliovirus vaccine stockpile from the National Vaccine Advisory Committee (NVAC) and the Advisory Committee on Immunization Practices (ACIP).

Paralytic poliomyelitis was once endemic in the United States; however, because of high vaccination levels, the last case of wild disease occurred in 1979. Although worldwide polio eradication may be achieved in the near future, the presence of undervaccinated children in urban areas and among groups who refuse vaccination creates an outbreak risk, should importation of wild virus occur. In 1999, the Advisory Committee on Immunization Practices (ACIP) recommended that inactivated poliovirus vaccine (IPV) be used for routine immunization of the US population and that oral poliovirus vaccine (OPV) be reserved for "mass vaccination campaigns to control outbreaks of paralytic polio.

The impact of reminder-recall interventions on low vaccination coverage in an inner-city population.

Background: Reminder-recall interventions have improved immunization rates in numerous studies.

Objective: To evaluate the impact of large-scale, registry-based reminder-recall interventions on low immunization rates in an inner-city population.

Design: Randomized, controlled, effectiveness trial.

Strategies to improve immunization rates and well-child care in a disadvantaged population: a cluster randomized controlled trial.

Objective: To measure the effect of a multimodal intervention on well-child care visit (WCV) and immunization rates in an inner-city population.

Design: Cluster randomized controlled trial.

Setting And Participants: One-year cohort of 2843 infants born at a hospital in an integrated inner-city health care system.

Primary-care visits and hospitalizations for ambulatory-care-sensitive conditions in an inner-city health care system.

Objective: Hospitalizations for ambulatory-care-sensitive conditions (ACSCs) are a marker for access barriers for children and a possible outcome measure for primary-care interventions. We assessed the relationship between primary-care utilization and subsequent ACSC hospitalization among inner-city children.

Methodology: We conducted a nested, case-control study of children born in 1993 in Denver Health (DH), a "safety-net" delivery system in Denver, Colo.

Immunization registry accuracy: improvement with progressive clinical application.

Background: Healthcare systems have been challenged to ensure the timely administration of immunizations. Immunization registries have been proposed to improve the accuracy and completeness of immunization information and to promote effective practice.

Methods: Comparison of randomly selected samples from two birth cohorts (1993 and 1998) from Denver Health Medical Center.

Rotavirus vaccine and the news media, 1987-2001.

Context: In August 1998, the US Food and Drug Administration licensed the first vaccine against rotavirus, the most important cause of severe childhood diarrhea. Fourteen months later, amid intense media activity, the vaccine was withdrawn after an association was found with intussusception.

Objectives: To examine the character of news media stories about rotavirus vaccine before and after intussusception became an issue, to evaluate what prompted the stories, and to assess the extent to which they evoked public reaction.

Childhood vaccination providers in the United States.

Objectives: This study sought to provide a characterization of US childhood vaccination providers.

Methods: The state was used as the analytic unit in examining 1997 data from the National Immunization Survey and the Vaccines for Children program, state immunization reports, and natality records.

Results: Overall, 57% of children were vaccinated in the private sector, 18% were vaccinated in the public sector, and 25% were vaccinated by a mixture of providers.