A limited measles outbreak in a highly vaccinated US boarding school

Measles vaccination coverage and immunization status of nurses: An interventional study in Türkiye

INTRODUCTION

Healthcare workers are more likely to contract measles than the general population. Our study aimed to assess measles vaccination and immunization levels among nurses, examine the influencing factors and implement an intervention program to increase immunization coverage.

MATERIALS AND METHODS

Our study was conducted in a university hospital in Türkiye. The study included 1012 nurses. It was an intervention study, continued between 01/11/2021 and 30/10/2023. Measles IgG and vaccination status of the participants were evaluated. Participants with negative measles IgG results who had not been vaccinated against measles or received a single dose of the vaccine were invited to the outpatient clinic to receive two doses. Participants who had received two doses of the measles vaccine and had negative measles IgG results were invited to the outpatient clinic for one dose of the measles vaccine. Nine hundred seventy-eight people participated in our study. The access frequency was 96.6%.

RESULTS

Among the participants aged 21-30, 68.4 % were Measles IgG (+). Measles IgG (+) prevalence was higher in women than men (85.3 % vs. 61.0 %). The department with the lowest measles IgG positivity was intensive care (75.8 %). Measles IgG (+) prevalence became higher as the duration of employment increased. The measles seropositivity in total population rose from 83.1 % before the intervention to 94.3 % after, to 91.8 % in the 21-30 age group, and to 90.2 % in male. Sixteen people had never received measles vaccination. Of the 37 participants who had previously received two doses of measles vaccine, 22 received a single dose and after the intervention 16 (72.7 %) were positive. Only 1 person was found to have vaccine refusal during the intervention.

CONCLUSION

Expanding the immunization scope in hospitals by screening for measles antibodies among healthcare personnel and vaccinating those who are seronegative can be considered an effective public health strategy.

A population study of the NYS measles epidemic: Lessons learned

OBJECTIVES

In 2019 the United States experienced the largest outbreak of measles in 27 years, 19 years after the United States declared measles eliminated. The purpose of this paper was to present a population study of a measles outbreak within Orthodox Jewish communities in New York that led to the elimination of religious exemption for school mandated vaccines.

METHODS

Peer reviewed articles, news media, health department, and government resources were used to investigate environmental factors that led to this outbreak. State, county, and city immunization records were accessed to explore measles compliance rates before and after policy change.

RESULTS

Rockland County had low compliance rates compared to the rest of the state, and the elimination of religious exemptions raised compliance rate almost to state level. In all but one affected New York City zip codes, compliance following policy change rose to 97.95%-99.15%.

CONCLUSIONS

Overall, changes in measles compliance rates reflect policy goals, but localized differences imply a need for more customized interventions for each unique community. Public health planning to promote vaccination should be sensitive to the concerns and perceptions of each community in order for health interventions to have a positive effect.

The Role of Sex, Ethnicity, Age, and Nutritional Status in the Seropositivity of the Measles Vaccine

AIM: This study investigates the relationship between sex, ethnicity, age, nutritional status with the seropositivity of the Edmonston-Zagreb vaccine in children. METHODS: A cross sectional, observational study was conducted. A total of 45 children were differentiated based on sex, ethnicity, age, and nutritional status when they received the Edmonston-Zagreb measle vaccine for the first time. Flow cytometry was used to look at differences in antibody status as well as populations of CD-4 and CD-8 cells that release IFN- γ. RESULTS: We found no significant differences in antibody levels or CD-4 and CD-8 cell populations that secrete IFN- γ between boys and girls (p > 0.05). Besides, similar results were also confirmed in comparisons between Javanese and Sundanese ethnic groups, 9 months versus more than 9 months of age, or normal versus low body mass index (p > 0.05). CONCLUSIONS: We conclude that sex, race, age, and nutritional status had no effect on immune response to vaccination. As a result, there was no barrier to seroconversion and optimal immunological performance in the children in this trial who received the Edmonston-Zagreb measles vaccination.

Measles in a measles-eliminated country: A case report of a measles-infected postpartum mother and infant in Japan

Japan has maintained measles elimination status since 2015. However, sporadic outbreaks of measles have been continuously reported. Here, we report a case of a measles-infected postpartum mother and infant in Japan. A 28-year-old Japanese woman, who had previously received a dose of the measles vaccination, experienced fever 5 days postpartum. Subsequently, a maculopapular rash appeared, and she was diagnosed with measles. Moreover, her baby developed a fever and maculopapular rash on the 13th day of life, 2 days after postexposure prophylaxis with intravenous immunoglobulin, and was also diagnosed with measles. Both showed full recovery. This case suggests that measles can still be a threat in a measles-eliminated country, and the administration of two doses of measles vaccination to women prior to childbearing age is crucial to protect newborns from measles.

Measles Outbreak at a Privately Operated Detention Facility: Arizona, 2016

BACKGROUND

We describe a measles outbreak and control measures implemented at a privately operated detention facility housing US Immigration and Customs Enforcement detainees in 2016.

METHODS

Case-patients reported fever and rash and were either laboratory-confirmed or had an epidemiological link to a laboratory-confirmed case-patient. Immunoglobulin G (IgG) avidity and plaque reduction neutralization tests distinguished between primary acute and reinfection case-patients. Measles-specific IgG was measured to assess detainee immunity levels. We compared attack rates (ARs) among detainees and staff, between IgG-negative and IgG-positive detainees, and by detainee housing units and sexes.

RESULTS

We identified 32 measles case-patients (23 detainees, 9 staff); rash onsets were during 6 May-26 June 2016. High IgG avidity and neutralizing-antibody titers >40000 to measles (indicating reinfection) were identified in 18 (95%) and 15 (84%) of 19 tested case-patients, respectively. Among 205 unit A detainees tested for presumptive immunity, 186 (91%) had detectable IgG. Overall, the AR was 1.65%. ARs were significantly higher among detainees in unit A (7.05%) compared with units B-F (0.59%), and among male (2.33%) compared with female detainees (0.38%); however, ARs were not significantly different between detainees and staff or between IgG-negative and IgG-positive detainees. Control measures included the vaccination of 1424 of 1425 detainees and 190 of 510 staff, immunity verification for 445 staff, case-patient isolation, and quarantine of affected units.

CONCLUSIONS

Although ARs were low, measles outbreaks can occur in intense-exposure settings, despite a high population immunity, underscoring the importance of high vaccination coverage and containment in limiting measles transmission.

Estimating the nationwide transmission risk of measles in US schools and impacts of vaccination and supplemental infection control strategies

BACKGROUND

The spread of airborne infectious diseases such as measles is a critical public health concern. The U.S. was certified measles-free in 2000, but the number of measles cases has increased in recent years breaking the record of the nationwide annual number of cases since 1992. Although the characteristics of schools have made them one of the most vulnerable environments during infection outbreaks, the transmission risk of measles among students is not completely understood. We aimed to evaluate how three factors influence measles transmission in schools: personal (vaccination), social (compartmentalizing), and building systems (ventilation, purification, and filtration).

METHODS

We used a combination of a newly developed multi-zone transient Wells-Riley approach, a nationwide representative School Building Archetype (SBA) model, and a Monte-Carlo simulation to estimate measles risk among U.S. students. We compared our risk results with the range of reported transmission rates of measles in school outbreaks to validate the risk model. We also investigated the effectiveness of vaccination and ten supplemental infection control scenarios for reducing the risk of measles transmission among students.

RESULTS

Our best nationwide estimate of measles transmission risk in U.S. schools were 3.5 and 32% among all (both unvaccinated and immunized) and unvaccinated students, respectively. The results showed the transmission risk of measles among unvaccinated students is > 70 times higher than properly immunized ones. We also demonstrated that the transmission risk of measles in primary schools (assuming teacher self-contained classrooms) is less than secondary schools (assuming departmentalized systems). For building-level interventions, schools with ductless-with-air-filter and ductless-without-air-filter systems have the lowest and highest transmission risks of measles, respectively. Finally, our simulation showed that infection control strategies could cut the average number of infected cases among all students in half when a combination of advanced air filtration, ventilation, and purification was adopted in the modeled schools.

CONCLUSIONS

Our results highlight the primary importance of vaccination for reducing the risk of measles transmission among students. Yet, additional and significant risk reduction can be achieved through compartmentalizing students and enhancing building ventilation and filtration systems.

Investigation of a measles transmission with vaccination: a case study in Jakarta, Indonesia

Measles is a contagious disease caused by the measles virus of genus Morbillivirus, which has been spreading in many affected regions. This infection is characterized by the appearance of rashes all over the body and potentially cause serious complications, especially among infants and children. Before measles immunization was promoted, it is one of the endemic diseases that caused the most fatalities each year in the world. This paper aims to analyze and to investigate measles transmission in Jakarta via an SIHR epidemic model involving vaccination from January to December 2017. Jakarta Health Office collected the observed data of measles incidence. We then derived the basic reproduction number as a threshold of disease transmission and obtained the local as well as global stability of the equilibria under certain conditions. The unobserved parameters and initial conditions were estimated by minimizing errors between data and numerical results. Furthermore, a stochastic model was developed to capture the data and to accommodate the randomness of the transmission. Sensitivity analysis was also performed to analyze and to identify the parameters which give significant contributions to the spread of the virus. We then obtained simulations of vaccine level coverage. The data is shown within a 95% confidence interval of the stochastic solutions, and the average of the stochastic solutions is relatively close to the solution of the deterministic model. The most sensitive parameter in the infected compartment is the hospitalized rate, which can be considered to be one of the essential factors to reduce the number of cases for policymakers. We hence proposed a control strategy which is providing treatment accesses easier for infected individuals is better than vaccinating when an outbreak occurs.

Measles and mumps outbreaks in Lebanon: trends and links

BACKGROUND

Lebanon has experienced several measles and mumps outbreaks in the past 20 years. In this article, a case-based surveillance of both measles and mumps outbreaks in Lebanon was carried out in an attempt to outline factors contributing to the failure of elimination plans and to provide potential solutions. The relationship between the outbreaks of both diseases was described and explored.

METHODS

A retrospective descriptive study of confirmed cases of measles and mumps in Lebanon between 2003 and 2018 collected from the Lebanese Ministry of Public Health Epidemiological Surveillance Unit public database was carried out. The information collected was graphically represented taking into consideration dates of reported cases, age groups affected, and vaccination status.

RESULTS

The mean number of measles cases was 150.25 cases/year in the 1-4 years age group, 87 cases/year in individuals aging between 5 and 14, and 63.68 cases/year in those > 14 years old. In the latter group, only 18.05% were unvaccinated. The mean number of mumps cases was 30.4 cases/year in the < 4 year age group and 53.8 cases/year in the 10-19 years age group. During the study period, every spike in measles cases was followed by a similar spike in mumps. 9.66% of measles cases occurred in individuals who received at least 2 doses of the vaccine, 52.26% in the unvaccinated, and 38% in those whose vaccination status was undetermined.

CONCLUSIONS

Measles in Lebanon is a disease of the pediatric population, but adults remain at risk. Outbreaks of mumps followed those of measles and were mainly among adolescents. Presence of a large number of Syrian refugees in the country may further complicate the situation. Vaccination activities need to be intensified.

Seroprevalence to Measles Virus after Vaccination or Natural Infection in an Adult Population, in Italy

An increase in measles cases worldwide, with outbreaks, has been registered in the last few years, despite the availability of a safe and highly efficacious vaccine. In addition to an inadequate vaccination coverage, even in high-income European countries studies proved that some vaccinated people were also found seronegative years after vaccination, thus increasing the number of people susceptible to measles infection. In this study, we evaluated the immunization status and the seroprevalence of measles antibodies among 1092 healthy adults, either vaccinated or naturally infected, in order to investigate the persistence of anti-measles IgG. Among subjects who received two doses of measles vaccine, the neutralizing antibody titer tended to decline over time. In addition, data collected from a neutralization assay performed on 110 healthy vaccinated subjects suggested an inverse correlation between neutralizing antibody titers and the time elapsed between the two vaccinations, with a significant decline in the neutralizing titer when the interval between the two doses was ≥11 years. On the basis of these results, monitoring the serological status of the population 10-12 years after vaccination could be important both to limit the number of people who are potentially susceptible to measles, despite the high efficacy of MMR vaccine, and to recommend a booster vaccine for the seronegatives.

Clinical Characteristics of Measles in Previously Vaccinated and Unvaccinated Patients in California

Background

Measles vaccine failure was first described in 1972. Over the next 20 years, vaccine failure was extensively studied, but during the last 25 years few investigations have been performed. We describe the clinical characteristics of measles in previously vaccinated and unvaccinated patients in California.

Methods

All confirmed measles cases reported to the California Department of Public Health from 1 January 2000 through 31 December 2015 were reviewed. Clinical characteristics (rates of hospitalization, cough, coryza, conjunctivitis, and fever) were compared between the previously unvaccinated, those who had had 1 dose of vaccine, and those who had had ≥2 doses of measles vaccine.

Results

There were 232 confirmed measles cases in whom vaccination status was verified; 80% were unvaccinated, 9% had had 1 dose of measles vaccine, and 11% had had ≥2 doses of measles vaccine. Subjects who had had ≥2 doses of measles vaccine had lower rates of hospitalization, cough, coryza, conjunctivitis, and fever than subjects who had 1 dose of measles vaccine or who were unimmunized.

Conclusions

Vaccine failure measles cases were less ill than cases that occurred in unvaccinated patients. Nevertheless, these cases still required the same amount of public health effort in tracing contacts as in cases who were unvaccinated.

Socioeconomic inequalities and measles immunization coverage in Ecuador: A spatial analysis

INTRODUCTION/BACKGROUND

Inequalities in measles immunization coverage facilitate the onset of outbreaks. This study aimed to quantify socioeconomic inequalities associated with measles immunization coverage at the population level.

METHODS

An ecological study was performed using two datasets: the results of a measles immunization survey performed in Ecuador, in 2011, and socioeconomic data from the 2010 census, aggregated by canton. The survey included 3,140,799 people aged 6 months to 14 years living in 220 cantons of Ecuador. Vaccinated children were considered those who received at least one dose of vaccine against measles. Multiple spatial regression was performed to identify socioeconomic inequalities associated with measles immunization coverage. The slope index of inequality and the relative index of inequality were calculated.

RESULTS

Vaccination coverage against measles was inversely associated with unsatisfied basic needs in urban areas (P < 0.01) and the proportions of indigenous and African-Ecuadorian residents in the canton (P = 0.015), and directly associated with unemployment rate in the canton (P = 0.037). The distribution of immunization coverage across the cantons was heterogeneous, indicating spatial dependence. The non-immunization rate was 71% higher in the poorer cantons than in the upper stratum cantons (prevalence ratio 1.71; 95%CI: 1.69-1.72). A difference of 10.6 percentage points was detected in immunization coverage between cantons with the best vs. worst socioeconomic level, according to the slope index of inequality. The relative index of inequality revealed that immunization coverage was 1.12 times higher in cantons with the highest socioeconomic level vs. cantons with the lowest socioeconomic level.

CONCLUSIONS

The spatial dependence between measles vaccination coverage and socioeconomic disparities suggests clusters of vulnerable populations for outbreaks. Health and social inequalities must be considered to achieve and maintain measles elimination.

Public health responses during measles outbreaks in elimination settings: Strategies and challenges

In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries. This review highlights the strategies used to limit measles spread in elimination settings: (1) assembly of an outbreak control committee; (2) isolation of measles cases while infectious; (3) exclusion and quarantining of individuals without evidence of immunity; (4) vaccination of susceptible individuals; (5) use of immunoglobulin to prevent measles in exposed susceptible high-risk persons; (6) and maintaining laboratory proficiency for confirmation of measles. Deciding on the extent of containment efforts should be based on the expected benefit of reactive interventions, balanced against the logistical challenges in implementing them.

Identifying risk factors associated with acquiring measles in an outbreak among age-appropriately vaccinated school children: a cohort analysis

BACKGROUND

A measles outbreak occurred in age-appropriately vaccinated children in a school in a town in the South East of Ireland in September-November 2013.

AIMS

The purpose of this study was to investigate the risk factors associated with catching measles during the outbreak.

METHODS

Ninety-five children (4-5 years) in three classes, in the first year of primary school, were included in the study. Immunisation records on the South East Child Health Information System for first Measles Mumps and Rubella (MMR) vaccine for the 95 children were reviewed. Data collected included age at MMR, date of administration of MMR, MMR brand and batch number, and the General Practice at which MMR was administered. The risk factors analysed included age at vaccination, time of vaccination, class and the GP practice where MMR was administered. Statistical analysis was performed using Epi info 7 and SPSS v24.

RESULTS

Thirteen children in the cohort developed measles during the outbreak. All children in the cohort were age-appropriately vaccinated, with one dose of MMR vaccine. Analysis demonstrated statistically significant differences in the relative risk of developing measles according to the class a child was in, and the General Practice at which they were vaccinated.

CONCLUSIONS

The reason for intense measles activity in one class was not established. Although a concurrent investigation into cold chain and vaccine stock management did not identify a cause for the high relative risk of measles in children vaccinated, recommendations were made for improving cold chain and vaccine stock management in General Practices.

Role of health determinants in a measles outbreak in Ecuador: a case-control study with aggregated data

BACKGROUND

In 2011-2012, an outbreak of measles occurred in Ecuador. This study sought to ascertain which population characteristics were associated.

METHODS

Case-control study of aggregate data. The unit of analysis was the parish (smallest geographic division). The national communicable disease surveillance database was used to identify 52 case parishes (with at least one confirmed case of measles) and 972 control parishes (no cases of measles). A hierarchical model was used to determine the association of measles with population characteristics and access to health care.

RESULTS

Case parishes were mostly urban and had a higher proportion of children under 1 year of age, heads of household with higher educational attainment, larger indigenous population, lower rates of measles immunization, and lower rates of antenatal care visit attendance. On multivariate analysis, associations were found with educational attainment of head of household ≥8 years (OR: 0.29; 95%CI 0.15-0.57) and ≥1.4% indigenous population (OR: 3.29; 95%CI 1.63-6.68). Antenatal care visit attendance had a protective effect against measles (OR: 0.98; 95%CI 0.97-0.99). Measles vaccination was protective of the outbreak (OR: 0.97; 95%CI 0.95-0.98). The magnitude of these associations was modest, but represents the effect of single protective factors, capable of acting at the population level regardless of socioeconomic, biological, and environmental confounding factors.

CONCLUSION

In Ecuador, the parishes with the highest percentage of indigenous populations and those with the lowest vaccination coverage were the most vulnerable during the measles outbreak.

An Evidence-Based Project Demonstrating Increased School Immunization Compliance Following a School Nurse-Initiated Vaccine Compliance Strategy

During the 2012-2013 school year, only 66% of students at a Northern Indiana High School were in compliance with school immunization requirements. We report here successful implementation of evidence-based, time, and cost-effective methods aimed at increasing school immunization compliance. A three-stage strategy initiated by the school nurse was employed. In the first stage, letters were sent home with students, indicating the lack of compliance with school immunization laws. The next stage involved a second letter sent home with the student which contained immunization information from the Indiana State Department of Health, appointment information, and a copy of the student's immunization record. In the final stage, letters were sent home via e-mail and phone calls were used for follow-up. At each stage, students and parents were given an explanation of exclusion and a date when exclusion would apply. Postintervention, vaccine compliance was 99.6%, exceeding both national and state averages.

Performance Evaluation of the VIDAS(®) Measles IgG Assay and Its Diagnostic Value for Measuring IgG Antibody Avidity in Measles Virus Infection

The objective of this study is primarily to compare the performance of the VIDAS(®) Measles immunoglobulin (Ig)G assay to that of two other serological assays using an immunoassay technique, Enzygnost(®) Anti-measles Virus/IgG (Siemens) and Measles IgG CAPTURE EIA(®) (Microimmune). The sensitivity and the agreement of the VIDAS(®) Measles IgG assay compared to the Enzygnost(®) Anti-measles Virus/IgG assay and the Measles IgG CAPTURE EIA(®) assay are 100%, 97.2% and 99.0%, 98.4%, respectively. The very low number of negative sera for IgG antibodies does not allow calculation of specificity. As a secondary objective, we have evaluated the ability of the VIDAS(®) Measles IgG assay to measure anti-measles virus IgG antibody avidity with the help of the VIDAS(®) CMV IgG Avidity reagent, using 76 sera from subjects with measles and 238 other sera. Different groups of populations were analyzed. In the primary infection measles group, the mean IgG avidity index was 0.16 (range of 0.07 to 0.93) compared to 0.79 (range of 0.25 to 1) in the serum group positive for IgG antibodies and negative for IgM. These data allow to define a weak anti-measles virus IgG antibody avidity as an avidity index (AI) < 0.3 and a strong avidity as an AI > 0.6. The VIDAS(®) Measles IgG assay has a performance equivalent to that of other available products. Its use, individual and quick, is well adapted to testing for anti-measles immunity in exposed subjects.

Eradication of measles: remaining challenges

Measles virus (MeV) is an aerosol-borne and one of the most contagious pathogenic viruses known. Almost every MeV infection becomes clinically manifest and can lead to serious and even fatal complications, especially under conditions of malnutrition in developing countries, where still 115,000 to 160,000 patients die from measles every year. There is no specific antiviral treatment. In addition, MeV infections cause long-lasting memory B and T cell impairment, predisposing people susceptible to opportunistic infections for years. A rare, but fatal long-term consequence of measles is subacute sclerosing panencephalitis. Fifteen years ago (2001), WHO has launched a programme to eliminate measles by a worldwide vaccination strategy. This is promising, because MeV is a human-specific morbillivirus (i.e. without relevant animal reservoir), safe and potent vaccine viruses are sufficiently produced since decades for common application, and millions of vaccine doses have been used globally without any indications of safety and efficacy issues. Though the prevalence of wild-type MeV infection has decreased by >90 % in Europe, measles is still not eliminated and has even re-emerged with recurrent outbreaks in developed countries, in which effective vaccination programmes had been installed for decades. Here, we discuss the crucial factors for a worldwide elimination of MeV: (1) efficacy of current vaccines, (2) the extremely high contagiosity of MeV demanding a >95 % vaccination rate based on two doses to avoid primary vaccine failure as well as the installation of catch-up vaccination programmes to fill immunity gaps and to achieve herd immunity, (3) the implications of sporadic cases of secondary vaccine failure, (4) organisation, acceptance and drawbacks of modern vaccination campaigns, (5) waning public attention to measles, but increasing concerns from vaccine-associated adverse reactions in societies with high socio-economic standards and (6) clinical, epidemiological and virological surveillance by the use of modern laboratory diagnostics and reporting systems. By consequent implementation of carefully designed epidemiologic and prophylactic measures, it should be possible to eradicate MeV globally out of mankind, as the closely related morbillivirus of rinderpest could be successfully eliminated out of the cattle on a global scale.

Measles Virus Neutralizing Antibody Response, Cell-Mediated Immunity, and Immunoglobulin G Antibody Avidity Before and After Receipt of a Third Dose of Measles, Mumps, and Rubella Vaccine in Young Adults

BACKGROUND

Two doses of measles, mumps, and rubella (MMR) vaccine are 97% effective against measles, but waning antibody immunity to measles and failure of the 2-dose vaccine occur. We administered a third MMR dose (MMR3) to young adults and assessed immunogenicity over 1 year.

METHODS

Measles virus (MeV) neutralizing antibody concentrations, cell-mediated immunity (CMI), and immunoglobulin G (IgG) antibody avidity were assessed at baseline and 1 month and 1 year after MMR3 receipt.

RESULTS

Of 662 subjects at baseline, 1 (0.2%) was seronegative for MeV-neutralizing antibodies (level, <8 mIU/mL), and 23 (3.5%) had low antibody levels (8-120 mIU/mL). One month after MMR3 receipt, 1 subject (0.2%) was seronegative, and 6 (0.9%) had low neutralizing antibodies, with only 21 of 662 (3.2%) showing a ≥ 4-fold rise in neutralizing antibodies. One year after MMR3 receipt, no subject was seronegative, and 10 of 617 (1.6%) had low neutralizing antibody levels. CMI analyses showed low levels of spot-forming cells after stimulation, suggesting the presence of T-cell memory, but the response was minimal after MMR3 receipt. MeV IgG avidity did not correlate with findings of neutralization analyses.

CONCLUSIONS

Most subjects were seropositive before MMR3 receipt, and very few had a secondary immune response after MMR3 receipt. Similarly, CMI and avidity analyses showed minimal qualitative improvements in immune response after MMR3 receipt. We did not find compelling data to support a routine third dose of MMR vaccine.

The Reemergence of Measles

Measles, or rubeola, is a highly infectious, acute viral illness of childhood that is considered eliminated in the USA but has reemerged in the past few years. Globally, an estimated 20 million cases of measles continue to occur, and it remains a leading cause of death among young children. It is rare in the USA and other first world countries, but numerous outbreaks have occurred in the USA recently, due to a combination of factors including poor vaccine coverage and importation of cases among travelers returning from endemic areas. The diagnosis of measles is usually made clinically, when an individual presents with a constellation of symptoms including cough, coryza, conjunctivitis, high fever, and an erythematous maculopapular rash in a cephalocaudal distribution. Complications are common and include otitis media, pneumonia, encephalitis, and rarely death. A measles vaccine is available in two doses and provides excellent protection against the disease. Despite this, vaccination coverage, especially among young adults, remains poor. Given its resurgence in the USA and other countries, interventions are urgently needed to address low vaccination rates and vaccine hesitancy. Measles awareness should also be a priority among young clinicians, who may have never seen a case or are not familiar with the disease.

An assessment of measles vaccine effectiveness, Australia, 2006-2012

OBJECTIVE

Vaccine effectiveness analysis serves as a critical evaluation for immunization programmes and vaccination coverage. It also contributes to maintaining public confidence with the vaccine providers. This study estimated measles vaccine effectiveness at the population level using Australian national notifications data between 2006 and 2012.

METHODS

Notification data were obtained from the National Notifiable Diseases Surveillance System. Vaccination status was classified according to whether a case had received zero, one or two doses of measles-containing vaccine. Cases aged less than 1 year and those with unknown vaccination status were excluded. All children with disease onset between 1 January 2006 and 31 December 2012 who were born after 1996 were included. Cases were matched to controls extracted from the Australian Childhood Immunization Register according to date of birth and jurisdiction of residence. Vaccine effectiveness was estimated by conditional logistic regression. Sensitivity analyses were conducted to test data robustness.

RESULTS

Vaccine effectiveness was estimated at 96.7% (95% confidence interval [CI]: 94.5-98.0%) for one dose and 99.7% (95% CI: 99.2-99.9%) for two doses of measles vaccine. For at least one dose, effectiveness was estimated at 98.7% (95% CI: 97.9-99.2%). Sensitivity analyses did not significantly alter the base estimates.

DISCUSSION

Vaccine effectiveness estimates suggested that the measles vaccine was protective at the population level between 2006 and 2012. However, vaccination coverage gaps may have contributed to recent measles outbreaks and may represent a serious barrier for Australia to maintain measles elimination status.

Measles in Healthcare Facilities in the United States During the Postelimination Era, 2001-2014

Between 2001 and 2014, 78 reported measles cases resulted from transmission in US healthcare facilities, and 29 healthcare personnel were infected from occupational exposure, 1 of whom transmitted measles to a patient. The economic impact of preventing and controlling measles transmission in healthcare facilities was $19 000-$114 286 per case.

Early childhood measles vaccinations are not associated with paediatric IBD: a population-based analysis

BACKGROUND

Early childhood vaccinations have been hypothesized to contribute to the emergence of paediatric inflammatory bowel disease [IBD] in developed countries. Using linked population-based administrative databases, we aimed to explore the association between vaccination with measles-containing vaccines and the risk for IBD.

METHODS

This was a case-control study using the University of Manitoba IBD Epidemiology Database [UMIBDED]. The UMIBDED was linked to the Manitoba Immunization Monitoring System [MIMS], a population-based database of immunizations administered in Manitoba. All paediatric IBD cases in Manitoba, born after 1989 and diagnosed before March 31, 2008, were included. Controls were matched to cases on the basis of age, sex, and region of residence at time of diagnosis. Measles-containing vaccinations received in the first 2 years of life were documented, with vaccinations categorized as 'None' or 'Complete', with completeness defined according to Manitoba's vaccination schedule. Conditional logistic regression models were fitted to the data, with models adjusted for physician visits in the first 2 years of life and area-level socioeconomic status at case date.

RESULTS

A total of 951 individuals [117 cases and 834 controls] met eligibility criteria, with average age of diagnosis among cases at 11 years. The proportion of IBD cases with completed vaccinations was 97%, compared with 94% of controls. In models adjusted for physician visits and area-level socioeconomic status, no statistically significant association was detected between completed measles vaccinations and the risk of IBD (adjusted odds ratio [AOR]: 1.5; 95% confidence interval [CI]: 0.5-4.4; p = 0.419].

CONCLUSIONS

No significant association between completed measles-containing vaccination in the first 2 years of life and paediatric IBD could be demonstrated in this population-based study.

Serological assessment of measles-rubella vaccination catch-up campaign among university students

BACKGROUND

In Japan, 5000-300,000 persons contracted measles every year until 2001. The measles/rubella-combined (MR) vaccination at age 17-18 years (phase 4 MR vaccination: MR-IV) was launched in 2008 in Japan as a measles-rubella catch-up campaign. A serological assessment of this campaign has not been thoroughly performed.

METHODS

Titers of anti-measles and anti-rubella immunoglobulin G antibodies, and past medical history including measles and rubella vaccination and infection were obtained from first-year university students in 2008 and 2009, and the immune status against measles and rubella was compared between students at the target MR-IV age (the target age group) and those 1 year older than the target age (non-target age group).

RESULTS

A total of 186 students were in the target age group and 146 were in the non-target age group. The proportion of students with a history of measles and rubella infection was not significantly different between the two groups (8.8% vs. 6.3%, P = 0.41 and 11.0% vs. 9.9%, P = 0.75, respectively). A history of two or more measles and rubella vaccinations was significantly more frequent in the target age group (85.2% and 54.9%, respectively) than in the non-target age group (20.8% and 13.2%, respectively; both P < 0.001). Prevalence of seropositivity for measles and for rubella was also higher in the target age group (98.9% and 97.8%, respectively) than in the non-target age group (91.0% and 87.5%, respectively; both P < 0.001).

CONCLUSIONS

The MR-IV catch-up campaign helped achieve herd immunity and will contribute to the elimination of measles and rubella.

Outbreak of measles among persons with prior evidence of immunity, New York City, 2011

BACKGROUND

Measles was eliminated in the United States through high vaccination coverage and a public health system able to rapidly respond to measles. Measles may occur among vaccinated individuals, but secondary transmission from such individuals has not been documented.

METHODS

Suspected patients and contacts exposed during a measles outbreak in New York City in 2011 were investigated. Medical histories and immunization records were obtained. Cases were confirmed by detection of measles-specific immunoglobulin M and/or RNA. Tests for measles immunoglobulin G (IgG), IgG avidity, measurement of measles neutralizing antibody titers, and genotyping were performed to characterize the cases.

RESULTS

The index patient had 2 doses of measles-containing vaccine; of 88 contacts, 4 secondary patients were confirmed who had either 2 doses of measles-containing vaccine or a past positive measles IgG antibody. All patients had laboratory confirmation of measles infection, clinical symptoms consistent with measles, and high-avidity IgG antibody characteristic of a secondary immune response. Neutralizing antibody titers of secondary patients reached >80 000 mIU/mL 3-4 days after rash onset and that of the index was <500 mIU/mL 9 days after rash onset. No additional cases of measles occurred among 231 contacts of secondary patients.

CONCLUSIONS

This is the first report of measles transmission from a twice-vaccinated individual with documented secondary vaccine failure. The clinical presentation and laboratory data of the index patient were typical of measles in a naive individual. Secondary patients had robust anamnestic antibody responses. No tertiary cases occurred despite numerous contacts. This outbreak underscores the need for thorough epidemiologic and laboratory investigation of suspected cases of measles regardless of vaccination status.

Factors precipitating outbreaks of measles in district Kangra of North India: A case-control study

Background:

Globally, measles is the fifth killer disease among children under five years of age. Despite high immunization coverage in Himachal, outbreaks are occurring. Upon two outbreaks in a hilly district in North India, a case control study was conducted to identify factors contributing to outbreaks and to recommend remedial measures to prevent further outbreaks.

Materials and Methods:

Factors were reviewed under three heads: program related, health care providers, and beneficiaries related. Cold chain maintenance was determined and responses were compared between workers from study Shahpur and control Nagrota Bagwan blocks. All 69 mothers of age and sex matched children with measles were enrolled. A pre-designed pre-tested data collection instrument was used. For statistical analysis, the odds ratio (OR) and adjusted odds ratio with 95% confidence interval (C.I.) among women of children exposed and unexposed to selected characteristics were calculated.

Results:

Poor cold chain maintenance and gaps in knowledge of health workers supplemented with beneficiary-related issues precipitated outbreaks in case area. Univariate analysis yielded strong statistical significance to 17 variables. Important statistically significant variables are educational status; OR 27.63 (C.I. 9.46-85.16); occupation; OR 0.35 (C.I. 0.16-0.75); income; OR 5.49 (C.I. 2.36-13.00); mode of transport to health care facility; OR 8.74 (C.I. 2.90-28.23); spread of illness from one person to another; OR 5.60 (95% C.I. 1.40-25.97); first help for sick child OR 2.12 (C.I. 1.00-4.50), and place of visit after recovery; OR 3.92 (C.I. 1.80-8.63). Multiple logistic regression yielded significant association with educational status, drinking water sources, and time taken to reach the nearest health facility.

Conclusion:

Measles outbreaks were confirmed in high immunization coverage areas. We recommend 2nd dose opportunity for measles (MR) between 5 and 17 years; refresher trainings to workers; mobile access to health care facility, and Information Education Communication activities for social behavioral change in affected areas.

Epidemiology of a mumps outbreak in a highly vaccinated island population and use of a third dose of measles-mumps-rubella vaccine for outbreak control--Guam 2009 to 2010

BACKGROUND

Despite high 2-dose measles-mumps-rubella (MMR) vaccine coverage, a large mumps outbreak occurred on the US Territory of Guam during 2009 to 2010, primarily in school-aged children.

METHODS

We implemented active surveillance in April 2010 during the outbreak peak and characterized the outbreak epidemiology. We administered third doses of MMR vaccine to eligible students aged 9-14 years in 7 schools with the highest attack rates (ARs) between May 18, 2010, and May 21, 2010. Baseline surveys, follow-up surveys and case-reports were used to determine mumps ARs. Adverse events postvaccination were monitored.

RESULTS

Between December 1, 2009, and December 31, 2010, 505 mumps cases were reported. Self-reported Pohnpeians and Chuukese had the highest relative risks (54.7 and 19.7, respectively) and highest crowding indices (mean: 3.1 and 3.0 persons/bedroom, respectively). Among 287 (57%) school-aged case-patients, 270 (93%) had ≥2 MMR doses. A third MMR dose was administered to 1068 (33%) eligible students. Three-dose vaccinated students had an AR of 0.9/1000 compared with 2.4/1000 among students vaccinated with ≤2 doses >1 incubation period postintervention, but the difference was not significant (P = 0.67). No serious adverse events were reported.

CONCLUSIONS

This mumps outbreak occurred in a highly vaccinated population. The highest ARs occurred in ethnic minority populations with the highest household crowding indices. After the third dose MMR intervention in highly affected schools, 3-dose recipients had an AR 60% lower than students with ≤2 doses, but the difference was not statistically significant and the intervention occurred after the outbreak peaked. This outbreak may have persisted due to crowding at home and high student contact rates.

Impact of a third dose of measles-mumps-rubella vaccine on a mumps outbreak

BACKGROUND AND OBJECTIVE

During 2009-2010, a northeastern US religious community experienced a large mumps outbreak despite high 2-dose measles-mumps-rubella (MMR) vaccine coverage. A third dose of MMR vaccine was offered to students in an affected community in an effort to control the outbreak.

METHODS

Eligible sixth- to 12th-grade students in 3 schools were offered a third dose of MMR vaccine. Baseline and follow-up surveys and physician case reports were used to monitor mumps attack rates (ARs). We calculated ARs for defined 3-week periods before and after the intervention.

RESULTS

Of 2265 eligible students, 2178 (96.2%) provided documentation of having received 2 previous doses of MMR vaccine, and a high proportion (1755 or 80.6%) chose to receive an additional vaccine dose. The overall AR for all sixth- to 12th-grade students declined from 4.93% in the prevaccination period to 0.13% after vaccination (P < .001). Villagewide, overall AR declined by 75.6% after the intervention. A decline occurred in all age groups but was significantly greater (96.0%) among 11- to 17-year-olds, the age group targeted for vaccination, than among all other age groups. The proportions of adverse events reported were lower than or within the range of those in previous reports of first- and second-dose MMR vaccine studies.

CONCLUSIONS

This is the first study to assess the impact of a third MMR vaccine dose for mumps outbreak control. The decline in incidence shortly after the intervention suggests that a third dose of MMR vaccine may help control mumps outbreaks among populations with preexisting high 2-dose vaccine coverage.

Measles-mumps-rubella revaccination; 18 months vs. 4-6 years of age: potential impacts of schedule changes

OBJECTIVE

The policy of administering the second dose of measles-mumps-rubella (MMR) vaccine (MMR(2)) has recently changed in Iran, at age 1.5 years instead of 4-6 years previously. The effects of such a change on the immune status of the individual are evaluated in this study.

METHODS

Totally 249 and 228 children aged 18 months and 4- to 6-year-olds, respectively, with a documented receipt of primary MMR vaccine at the age of ≥ 1 year were enrolled. Before, and 4-6 weeks after MMR(2) administration, anti-MMR IgG antibody levels were measured using ELISA method. IgM antibody levels were also assessed in measles-rubella seronegative children that responded to MMR(2). Collected data for each component from both age groups were compared by using Fischer's exact probability and chi-square tests.

RESULTS

Before revaccination, measles seroimmunity rate was similar between the two groups, but rates to mumps and rubella were significantly higher in younger children-measles: 74 vs. 78.3%; mumps: 82.3 vs. 68.4% and rubella: 75% vs. 67%, respectively. After administration of MMR(2), all seroimmune subjects were IgG boosted. Except for rubella, older seronegative children showed significantly higher seroconvertion rate to MMR(2) and seroprevalence rates increased in vaccinees--measles: 98.2 vs. 94%, mumps: 97 vs. 94.4% and rubella: 87 vs. 92.4%, respectively. Only few measles-rubella seronegative children showed IgM response to MMR(2).

CONCLUSION

This study showed that the majority of younger children were susceptible to MMR infection before revaccination. Earlier age policy provides more protection against MMR in preschool-aged children. Rubella strain seems to be less potent than reported.

Toward rubella elimination in Poland: need for supplemental immunization activities, enhanced surveillance, and further integration with measles elimination efforts

BACKGROUND

All Member States of the World Health Organization (WHO) European Region have endorsed rubella elimination and congenital rubella syndrome (CRS) prevention. However, Poland has continued high levels of reported rubella.

METHODS

We reviewed rubella incidence in Poland since 1966 and analyzed national aggregated surveillance data from the period 2003-2008 and case-based data from 4 provinces from the period 2006-2008. We described CRS cases since 1997 and assessed maternal receipt of vaccine. We reviewed national vaccination coverage from 1992 through 2008.

RESULTS

Since 1966, rubella outbreaks have occurred every 4-6 years in Poland. Aggregate and case-based data from the period 2003-2008 indicate that rubella virus transmission has occurred across wide age ranges (from <1 year to 60 years), with disproportionately higher percentage of cases among adolescent boys. Of 18 children with reported CRS cases from 1997 through 2008, 15 (83%) of their mothers had not been vaccinated. Measles-mumps-rubella dose 1 vaccination coverage ranged from 97% to 99%.

CONCLUSIONS

Poland had the highest incidence of rubella in the WHO European Region in 2007 and 2008. Rubella occurs predominantly in age and sex cohorts historically not included in vaccination recommendations. The risk for CRS continues. To achieve rubella elimination, supplemental immunization activities among adolescent boys are needed, as is integration with measles elimination efforts.

Measles outbreak associated with an international youth sporting event in the United States, 2007

BACKGROUND

Despite elimination of endemic measles in the United States (US), outbreaks associated with imported measles continue to occur. In 2007, the initiation of a multistate measles outbreak was associated with an imported case occurring in a participant at an international youth sporting event held in Pennsylvania.

METHODS

Case finding and contact tracing were conducted. Control measures included isolating ill persons and administering postexposure prophylaxis to exposed persons without documented measles immunity. Laboratory evaluation of suspected cases and contacts included measles serologic testing, viral culture, detection of viral RNA by reverse-transcription polymerase chain reaction, and viral genotyping.

RESULTS

The index case occurred in a child from Japan aged 12 years. Contact tracing among 1250 persons in 8 states identified 7 measles cases; 5 (71%) cases occurred among persons without documented measles vaccination. Epidemiologic and laboratory investigation supported a single chain of transmission, linking the outbreak to contemporaneous measles virus genotype D5 transmission in Japan. Of the 471 event participants, 193 (41%) lacked documentation of presumed measles immunity, 94 (49%) of 193 were US-resident adults, 19 (10%) were non-US-resident adults (aged >18 years), and 80 (41%) were non-US-resident children.

DISCUSSION

Measles outbreaks associated with imported disease are likely to continue in the US. Participants in international events, international travelers, and persons with routine exposure to such travelers might be at greater risk of measles. To reduce the impact of imported cases, high measles, mumps, and rubella vaccine coverage rates should be maintained throughout the US, and support should continue for global measles control and elimination.

Estimation of measles vaccine efficacy and critical vaccination coverage in a highly vaccinated population

Measles is a highly infectious disease that has been targeted for elimination from four WHO regions. Whether and under which conditions this goal is feasible is, however, uncertain since outbreaks have been documented in populations with high vaccination coverage (more than 90%). Here, we use the example of a large outbreak in a German public school to show how estimates of key epidemiological parameters such as the basic reproduction number (R(0)), vaccine efficacy (VE(S)) and critical vaccination coverage (p(c)) can be obtained from partially observed outbreaks in highly vaccinated populations. Our analyses rely on Bayesian methods of inference based on the final size distribution of outbreak size, and use data which are easily collected. For the German public school the analyses indicate that the basic reproduction number of measles is higher than previously thought (R(0) = 30.8, 95% credible interval: 23.6-40.4), that the vaccine is highly effective in preventing infection (VE(S) = 0.997, 95% credible interval: 0.993-0.999), and that a vaccination coverage in excess of 95 per cent may be necessary to achieve herd immunity (p(c) = 0.971, 95% credible interval: 0.961-0.978). We discuss the implications for measles elimination from highly vaccinated populations.

Measles outbreak linked to a minority group in Austria, 2008

We report on a measles outbreak originating in an anthroposophic community in Austria, 2008. A total of 394 (94·9%) cases fulfilled the outbreak case definition including 168 cases affiliated to the anthroposophic community. The source case was a school pupil from Switzerland. The Austrian outbreak strain was genotype D5, indistinguishable from the Swiss outbreak strain. A school-based retrospective cohort study in the anthroposophic school demonstrated a vaccine effectiveness of 97·3% in pupils who had received a single dose of measles-containing vaccine and 100% in those who had received two doses. The vaccination coverage of the cases in the anthroposophic community was 0·6%. Of the 226 outbreak cases not belonging to the anthroposophic community, the 10–24 years age group was the most affected. Our findings underline the epidemiological significance of suboptimal vaccination coverage in anthroposophic communities and in older age groups of the general population in facilitating measles virus circulation. The findings of this outbreak investigation suggest that the WHO European Region is unlikely to achieve its 2010 target for measles and rubella elimination.

Two Highly Immunized Hilly Areas versus Double Measles Outbreak Investigations in District Kangra, Himachal Pradesh, India, in 2006

BACKGROUND

We investigated two sequential outbreaks of measles in seven villages of Kangra, to confirm the diagnosis and to formulate recommendations for prevention and control.

METHODS

We defined a case of measles as occurrence of fever with rash in a child aged six months to 17 years during the period 3(rd) September to 23(rd) November 2006. We collected information on age, sex, residence, date of onset, symptoms, signs, treatment taken, traveling history and vaccination status. We described the outbreak by time, place and person. We estimated vaccine coverage and efficacy in the affected villages. We confirmed diagnosis clinically, serologically and through genotyping of the virus.

RESULTS

We identified 69 cases. Overall attack rates ranged between 4.2% and 6%. All case patients were between 6 years to 11 years of age. Age-specific attack rate in double outbreaks ranged in between 1.7% and 21.6%, the highest being in the age range 11-17 years. No deaths or complications were reported. The epidemic curve was suggestive of typical propagated pattern. The first outbreak imported virus after an interschool game competition (relative risk, 6.44%; 95% confidence interval, 3.81-10.91); followed by the second outbreak, in which people exchanged foods in the festival in one infected village of the first outbreak (relative risk, 5.3; 95% confidence interval, 1.90-14.77; P <.001). The calculated immunization coverage (93%) coincided nearly with administrative claims. The vaccine efficacies were estimated to be 85% and 81% in the first and second outbreaks respectively. Eleven of the 16 case patients were tested for measles IgM antibodies, while two nasopharyngeal swabs were positive by polymerase chain reaction (PCR) and are genotyped D4 measles strain. Vitamin A supplementations were only given in four villages.

CONCLUSION

Measles outbreaks were confirmed in high-immunization-coverage areas. We recommended (i) second dose opportunity for measles in Himachal Pradesh and (ii) vitamin A supplementation to all the case patients.

Ongoing measles and rubella transmission in Georgia, 2004-05: implications for the national and regional elimination efforts

BACKGROUND

In 2004-05, Georgia experienced large-scale concurrent measles and rubella outbreaks. We analysed measles and rubella epidemiology in Georgia to describe disease trends, determine the cause of the outbreaks, identify challenges to achieving disease elimination goals and propose interventions to overcome them.

METHODS

We reviewed national measles and rubella surveillance and vaccination coverage data, focusing on the 2004-05 outbreaks, and conducted a measles vaccine effectiveness (VE) study using data from a 2004 school-based outbreak.

RESULTS

Before 2004, the last large measles outbreak after measles vaccination was introduced (in 1966) in Georgia, was in 1988 (incidence rate, 36/100 000); the highest year for rubella was 1985 (110/100 000). During 2004-05, 8391 measles cases and 5151 rubella cases were reported (most of them diagnosed clinically). Of 358 suspected measles cases tested, 181 (51%) were positive for measles-IgM antibody; of 240 suspected rubella cases tested, 50 (21%) were positive for rubella-IgM antibody. Over 90% of measles cases were in persons born after 1979; 90% of rubella cases were in persons born after 1987. Approximately 41% of measles cases and 88% of rubella cases were unvaccinated. Estimated measles VE (>/=1 vs 0 doses) was 86% (95% CI, 58-96%).

CONCLUSIONS

The outbreak likely resulted from failure to vaccinate rather than vaccine failure. Susceptible persons likely accumulated due to the long absence of large outbreaks and decreased coverage after the collapse of Soviet Union. To interrupt measles and rubella transmission in Georgia and achieve disease elimination goals by 2010, supplementary immunization activities should target children and young adults.

Long-term persistence of mumps antibody after receipt of 2 measles-mumps-rubella (MMR) vaccinations and antibody response after a third MMR vaccination among a university population

BACKGROUND

High attack rates among vaccinated young adults reported during the 2006 mumps outbreak in the United States heightened concerns regarding mumps vaccine failure.

METHODS

Serum specimens from university students and staff were tested for mumps immunoglobulin (Ig) G by enzyme immunoassay (EIA). A subset of participants vaccinated for < or =5 years and > or =15 years were tested by neutralizing antibody (NA) assay. Persons seronegative by EIA were offered a third dose of measles-mumps-rubella vaccine (MMR3), and serum specimens were obtained 7-10 days and 2-3 months after its administration.

RESULTS

Overall, 94% (95% confidence interval [CI], 91%-96%) of the 440 participants were seropositive. No differences existed in seropositivity rates by sex, age, age at receipt of the second dose of MMR vaccine (MMR2), or time since receipt of MMR2 (P = .568). The geometric mean titer (GMT) of NA among persons vaccinated with MMR2 during the previous 1-5 years was 97 (95% CI, 64-148), whereas, among those vaccinated > or =15 years before blood collection, the GMT was 58 (95% CI, 44-76) (P = .065). After MMR3, 82% (14/17) and 91% (10/11) seroconverted in 7-10 days and 2-3 months, respectively.

CONCLUSIONS

Lower levels of NA observed among persons who received MMR2 > or =15 years ago demonstrates antibody decay over time. MMR3 vaccination of most seronegative persons marked the capacity to mount an anamnestic response.

Measles outbreak associated with a church congregation: a study of immunization attitudes of congregation members

OBJECTIVES

Although measles has not been endemic in the U.S. since 1997 due to high vaccination coverage, recent U.S. measles outbreaks have been associated with individuals and groups who have refused vaccination for philosophical, cultural, or religious reasons. One such outbreak occurred in Indiana among a group of church members in May and June of 2005. Our objectives were to: (1) determine attitudes and beliefs of church leaders and members regarding vaccinations and the outbreak experience, (2) describe reasons for vaccine acceptance and nonacceptance, and (3) assess the feasibility of a knowledge and attitudes study in the context of a vaccine-preventable disease outbreak.

METHODS

We conducted a focus group with church leaders and families and held 12 structured household interviews with church members directly and indirectly involved in the outbreaks.

RESULTS

A combination of safety concerns, personal experience, and religious beliefs contributed to vaccination refusal among a subgroup of church members. While the experience with measles disease did not necessarily translate into a more positive perception of vaccines, most families that refused vaccination would accept some future vaccines under unique circumstances, such as disease presence in the community or if vaccination could be delayed until a child was older.

CONCLUSIONS

Lessons learned from this outbreak experience can inform future outbreak investigations elsewhere. Maintaining open communication with parents who refuse immunizations, as well as working with their trusted social networks, can help public health professionals facilitate alternative means of disease control during a vaccine-preventable disease outbreak in the community.

New, and some not-so-new, vaccines for adolescents and diseases they prevent

Adolescents in the United States now have the opportunity to receive new vaccines that prevent invasive meningococcal infections, pertussis (whooping cough), and cervical cancer. Except for their potential to cause serious illness, these infections could not be more different. Their incidence ranges from extremely low to quite high. Early clinical manifestations of infection range from none to life-threatening illness. Two of the vaccines are similar to those already in use, whereas 1 is completely new. In conjunction with the 4 vaccines previously recommended for adolescents (the tetanus and diphtheria booster, hepatitis B, measles-mumps-rubella, and varicella), the 3 new vaccines (meningococcal, human papillomavirus, and the tetanus-diphtheria-pertussis booster [which replaced the tetanus-diphtheria booster]) bring the number recommended for adolescents to 6. In this article, we describe key characteristics of the 3 new vaccines and infections they were designed to prevent. We also briefly discuss other vaccines recommended for all adolescents who have not already received them and new vaccines that are still under development.

Large measles outbreak at a German public school, 2006

BACKGROUND

In 2006, a large measles outbreak (n = 614) occurred in Duisburg city, Germany, with 54% of cases aged >9 years. An investigation was launched to determine reasons for the resurgence of measles, assess vaccination coverage and vaccine effectiveness (VE).

METHODS

A retrospective cohort-study was undertaken at a Duisburg public school affected early in the outbreak. We distributed questionnaires to all 1250 students aged 10-21 years and abstracted vaccination records. Cases were identified according to a standard clinical case definition.

RESULTS

Questionnaires were returned by 1098 (88%) students. Vaccination records were abstracted from 859 students, of whom 820 (95.4%) had received at least one, 605 (70.4%) 2, and 39 (4.5%) no dose(s) of measles-containing vaccine (MCV). Coverage with 2 doses was higher in younger students. We identified 53 cases (attack rate = 5%). Measles-virus sequencing revealed genotype D6. After excluding students vaccinated in 2006 and those with a history of measles, the attack rate was 53% in unvaccinated students, 1.0% in students with one, and 0.4% in those with 2 MCV-doses. VE was 98.1% (95% CI: 92-100%) in students with one and 99.4% (95% CI: 97-100%) with 2 MCV-doses. Based on observed attack rates in vaccinated and unvaccinated students with vaccination records and in students without vaccination records, one-dose-coverage among all participating students was estimated at 91%.

CONCLUSIONS

VE was high. Vaccination coverage was, however, insufficient to prevent the outbreak. Immunization gaps were found especially in older students. To prevent further outbreaks and to achieve the goal of measles elimination in Germany, vaccination coverage must be increased.

Persistence of antibodies induced by measles-mumps-rubella vaccine in children in India

Antibody levels in 41 Indian girls were measured 6 years after measles-mumps-rubella (MMR) vaccination. Rates of seropositivity were 88% (measles antibodies), 95% (mumps antibodies), and 100% (rubella antibodies). The MMR vaccine induces long-term immunity in a majority of vaccinees; however, due to the observation of some seronegative vaccinees, the policy of administering a second dose of the MMR vaccine seems appropriate.

The benefit of molecular characterization during a measles upsurge in Denmark

Molecular characterization of measles virus was part of the epidemiological investigation of 27 measles cases reported in Denmark in 2006. RT-PCR detected measles virus RNA from various types of clinical specimens in 24 cases. Virus genotypes were determined by sequencing the nucleocapsid (N) gene. Four different genotypes, B3, D4, D5 and D9 were identified including two variants of the D4 genotype. In combination with the epidemiological data four clusters of measles cases and three sporadic cases were revealed. Our study showed that measles in Denmark resulted from imported measles virus strains. The limited duration and short chain of transmission of the identified clusters ascertain that the interruption of measles virus circulation is being sustained. However, measles transmission still has a potential to occur. To minimise the development of pools of susceptible individuals high (>/=95%) routine vaccination coverage with two doses of measles-containing vaccine needs to be attained. Molecular epidemiological studies have proved to be both a useful and a necessary component of an enhanced surveillance system required in the measles elimination phase.

Measles-mumps-rubella and varicella vaccine responses in extremely preterm infants

OBJECTIVE

Extremely preterm infants mount lower antibody responses than term infants to several vaccines. The objective of this study was to measure the immunogenicity of measles-mumps-rubella and varicella vaccines in preterm and term children.

METHODS

Immune status before immunization and immune response after immunization with measles-mumps-rubella and varicella vaccines at 15 months of age were compared in 32 infants, 16 of whom were preterm (< 29 weeks' gestation) and 16 of whom were term (> or = 37 weeks' gestation) at birth. Blood was drawn before vaccination and 3 to 6 weeks thereafter. Measles antibody was measured by plaque reduction neutralization assay. Mumps and rubella immunoglobulin G were measured in available sera by enzyme-linked fluorescent immunoassay. Varicella immunoglobulin G was measured in available sera by glycoprotein enzyme-linked immunosorbent assay. Values that were above or below the assay limits were assigned values double or half those limits, respectively. The primary outcome was the geometric mean antibody titer.

RESULTS

Preterm children had lower mumps and rubella geometric mean titers than did term children before vaccine, and nearly all children were seronegative for each of the 4 vaccine antigens before immunization. Measles, mumps, rubella, and varicella geometric mean titers were similar between groups after vaccine. All children were seropositive for measles after vaccine, whereas 13 of 14 preterm and 11 of 13 term children were seropositive for mumps, 13 of 14 preterm and 13 of 13 term children were seropositive for rubella, and 11 of 16 preterm and 9 of 15 term children were seropositive for varicella.

CONCLUSIONS

Preterm children mounted antibody responses that were similar to those of term children after measles-mumps-rubella and varicella vaccines at 15 months of age.