BACKGROUND:In Korea, measles occurs mainly in infants<12months of age, who are unvaccinated. In addition, vaccine populations, including adolescents and young adults, can become infected though importation. Thus, the question arises whether the current level of herd immunity in Korea is now insufficient for protecting against measles infection.

METHODS:Age-specific measles seroprevalence was evaluated by performing enzyme immunoassays and plaque reduction-neutralization tests on 3050 subjects aged 0-50years (birth cohort 1964-2014) and 480 subjects aged 2-30years (birth cohort 1984-2012).

RESULTS:The overall seropositivity and measles antibody concentrations were 71.5% and 1366mIU/mL, respectively. Progressive decline in antibody levels and seropositivity were observed over time after vaccination in infants, adolescents, and young adults. The accumulation of potentially susceptible individuals in the population was confirmed by comparing data from 2010 and 2014 seroprevalence surveys. The statistical correlation between measles incidence and measles seronegativity was determined.

CONCLUSIONS:Waning levels of measles antibodies with increasing time post-vaccination suggests that measles susceptibility is potentially increasing in Korea. This trend may be related to limitations of vaccine-induced immunity in the absence of natural boosting by the wild virus, compared to naturally acquired immunity triggered by measles infection. This study provides an important view into the current measles herd immunity in Korea.

We quantified measles transmissibility during a measles outbreak in Ohio in 2014 to evaluate the impact of public health responses. Case incidence and the serial interval (time between symptom onset in primary cases and secondary cases) were used to assess trends in the effective reproduction number R (the average number of secondary cases generated per case). A mathematical model was parameterized using early R values to determine the size and duration of the outbreak that would have occurred if containment measures had not been initiated, as well as the impact of vaccination. As containment started, we found a 4-fold decline in R (from approximately 4 to 1) over the course of 2 weeks and maintenance of R<1 as control measures continued. Under a conservative scenario, the model estimated 8,472 cases (90% confidence interval (CI): 8,447, 8,489) over 195 days (90% CI: 179, 223) without control efforts and 715 cases (90% CI: 103, 1,338) over 128 days (90% CI: 117, 139) when vaccination was included; 7,757 fewer cases (90% CI: 7,130, 8,365) and 67 fewer outbreak days (90% CI: 48, 98) were attributed to vaccination. Vaccination may not account entirely for transmission reductions, suggesting that changes in community behavior (social distancing) and other control efforts (isolation, quarantining) are important. Our findings highlight the benefits of measles outbreak response and of understanding behavior change dynamics.

Measles virus may persist in intestinal tissue, particularly that affected by Crohn's disease, and early exposure to measles may be a risk factor for the development of Crohn's disease. Crohn's disease and ulcerative colitis occur in the same families and may share a common aetiology. In view of the rising incidence of inflammatory bowel disease (Crohn's disease and ulcerative colitis), we examined the impact of measles vaccination upon these conditions. Prevalences of Crohn's disease, ulcerative colitis, coeliac disease, and peptic ulceration were determined in 3545 people who had received live measles vaccine in 1964 as part of a measles vaccine trial. A longitudinal birth cohort of 11,407 subjects was one unvaccinated comparison cohort, and 2541 partners of those vaccinated was another. Compared with the birth cohort, the relative risk of developing Crohn's disease in the vaccinated group was 3.01 (95% CI 1.45-6.23) and of developing ulcerative colitis was 2.53 (1.15-5.58). There was no significant difference between these two groups in coeliac disease prevalence. Increased prevalence of inflammatory bowel disease, but not coeliac disease or peptic ulceration, was found in the vaccinated cohort compared with their partners. These findings suggest that measles virus may play a part in the development not only of Crohn's disease but also of ulcerative colitis.

BACKGROUND/PURPOSE:Along with the improving vaccine coverage, suspected vaccine-associated measles has been reported in Zhejiang Province, China. In order to maintain the accuracy of the measles surveillance system, it is critical to discriminate between measles vaccine and wild-type virus.

METHODS:Eight suspected cases of vaccine-associated measles were reported in Zhejiang Province during 2011 and 2014. Sera collected within 4 days and throat swabs collected within 6 days after rash onset were tested with immunoglobulin M and measles virus (MeV) RNA to confirm MeV infection. In order to further identify the vaccine-associated cases, throat swabs with positive MeV RNA were tested using an allelic discrimination real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay developed in this study, RT-PCR-restriction fragment length polymorphism (RFLP) recommended by the National Measles Laboratory, and RT-PCR followed by sequencing and genotyping.

RESULTS:Combining anti-measles immunoglobulin M and RNA testing, eight cases were confirmed as MeV infection. Of the eight, two were identified as vaccine-associated cases by the allelic discrimination rRT-PCR assay, and one was identified by RT-PCR-RFLP. Subsequent sequencing and genotyping confirmed that the sequences of the two cases were identical to that of the Chinese vaccine strain. The developed allelic discrimination rRT-PCR was 10 times more sensitive than the RT-PCR-RFLP assay when RNA standards generated from three genotypes of MeV were tested.

CONCLUSION:Vaccine-associated measles has been identified in Zhejiang. The developed allelic discrimination rRT-PCR assay is rapid and sensitive, which will facilitate the surveillance for vaccine-associated measles.

BACKGROUND:The largest measles epidemic in North America in the last decade, occurred in 2011 in Quebec, Canada, where rates of 1- and 2-dose vaccine coverage among children 3 years of age were 95%-97% and 90%, respectively, with 3%-5% unvaccinated.

METHODS:Case patients identified through passive surveillance and outbreak investigation were contacted to determine clinical course, vaccination status, and possible source of infection.

RESULTS:There were 21 measles importations and 725 cases. A superspreading event triggered by 1 importation resulted in sustained transmission and 678 cases. The overall incidence was 9.1 per 100,000; the highest incidence was in adolescents 12-17 years old (75.6 per 100,000), who comprised 56% of case patients. Among adolescents, 22% had received 2 vaccine doses. Outbreak investigation showed this proportion to have been an underestimate; active case finding identified 130% more cases among 2-dose recipients. Two-dose recipients had milder illness and a significantly lower risk of hospitalization than those who were unvaccinated or single-dose recipients.

CONCLUSIONS:A chance superspreading event revealed an overall level of immunity barely above the elimination threshold when unexpected vulnerability in 2-dose recipients was taken into account. Unvaccinated individuals remain the immunization priority, but a better understanding of susceptibility in 2-dose recipients is needed to define effective interventions if elimination is to be achieved.

We report the brain magnetic resonance (MR) imaging abnormalities observed at the basal ganglia system of 5 patients (2 female and 3 male), who fulfilled the criteria of parkinsonism. The onset of parkinsonian syndrome ranged from 5 to 52 years old. All patients underwent MR exams with a 1.5T MR equipment. High field T2-weighted sequences disclosed hypersignal bilateral and symmetrically located exclusively at substantia nigra (3 cases), exclusively at globus pallidus (1case) and simultaneously at substantia nigra, globus pallidus and nigro-strital interconnections (1case). For three patients, the diagnose of secondary parkinsonism was supported by clinical data: the first had the onset of the symptoms after the exposure to an herbicide (glyphosate); the second after vaccination against measles; the third after coma due to encephalitis. For the other two patients, the onset of PS was progressive, resembling a typical idiopathic Parkinson's disease (PD) but the findings at the MR dimissed this initial diagnose. In this study, the contribution of neuroimaging was crucial to recognize secondary parkinsonism though the ethiological agents could not be determined in these patients.

Live measles vaccine (MV) may have beneficial off-target/non-specific effects (NSEs) reducing child mortality beyond prevention of measles infection. In contrast, the non-live pentavalent (Diphtheria-Tetanus-Pertussis-H. influenzae Type B-Hepatitis B) vaccine has no beneficial NSEs. The NSEs are strongest for the most recent vaccine. Hence, sequence of vaccination may affect survival. In Guinea-Bissau, we followed 7094 measles-vaccinated children prospectively from first home visit after 9 months (when MV is scheduled) to 5 years of age. We compared survival by sequence of MV and third Pentavalent vaccine (Penta3; scheduled at 3½ months) in Cox proportional-hazards models. Compared with being vaccinated in-sequence (Penta3-then-MV), having received out-of-sequence Penta3-after-MV before the visit was associated with an adjusted Hazard Ratio (aHR) of 1.19 (95%CI: 0.84-1.69); Receiving missing Penta doses on the visit date tended to be associated with higher mortality (aHR = 1.87 (0.96-3.65)) while not receiving missing doses of Penta was not (aHR = 0.93 (0.57-1.54)), test for interaction p = 0.09.

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.

A 5-year-old boy, with a history of fever beginning 15 days after a vaccination for measles, developed a rigid-akinetic syndrome 3 days after the fever began. A spinal tap obtained 1 week after the onset of fever showed pleocytosis with a monocellular pattern. A CT scan of the head and EEG did not disclose any abnormality. An MRI performed 3 months after the event, however, showed clear-cut evidence of bilateral substantia nigra lesions, suggesting secondary gliosis. The response to levodopa was good, but adverse reactions appeared early. The child is now 7 years old. Bromocriptine, deprenyl, and levodopa have produced a remarkable improvement of the parkinsonian features.

Thirty years after passage of legislation that created the National Vaccine Advisory Committee (NVAC)"to achieve optimal prevention of human infectious diseases through immunization and to achieve optimal prevention against adverse reactions to vaccines,"this review reflects NVAC's role and impact on the U.S. vaccine and immunization enterprise as an external advisor to the Department of Health and Human Services. We reviewed the history of NVAC in the context of the principles of its establishment, with a focus on its reports and recommendations. We performed a systematic literature review to identify NVAC reports published in widely-accessible public health journals, and we reviewed the available archives to identify other reports and resolutions approved by the committee not published in journals. We characterized key issues considered by NVAC according to the five goals of the 2010 National Vaccine Plan. The predominance of NVAC activities to date related to the implementation of immunization across the lifespan and the many aspects of the system needed to foster the goal of full immunization. Reflecting on the impacts of NVAC to date, this review identified 30 NVAC approved reports published in journals, 22 stand-alone resolutions, and 26 unique unpublished reports. The development of new and improved vaccines continues to represent a significant priority for NVAC, and we identified several challenges related to future vaccine innovation. Given the many factors that impact on policy changes in the vaccine and immunization enterprise, we encountered challenges associated with demonstrating attribution of specific policy changes to NVAC recommendations. Although difficult to quantify, this review suggests that NVAC played an important role in the improvements in the U.S. immunization enterprise over the past 30 years and that NVAC can and will continue to play an important role supporting U.S. immunization going forward.

BACKGROUND:There are insufficient system-wide transcriptomic (or other) data that help explain the observed inter-individual variability in antibody titers after measles vaccination in otherwise healthy individuals.

METHODS:We performed a transcriptome(mRNA-Seq)-profiling study after in vitro viral stimulation of PBMCs from 30 measles vaccine recipients, selected from a cohort of 764 schoolchildren, based on the highest and lowest antibody titers. We used regression and network biology modeling to define markers associated with neutralizing antibody response.

RESULTS:We identified 39 differentially expressed genes that demonstrate significant differences between the high and low antibody responder groups (p-value≤0.0002, q-value≤0.092), including the top gene CD93 (p<1.0E-13, q<1.0E-09), encoding a receptor required for antigen-driven B-cell differentiation, maintenance of immunoglobulin production and preservation of plasma cells in the bone marrow. Network biology modeling highlighted plasma cell survival (CD93, IL6, CXCL12), chemokine/cytokine activity and cell-cell communication/adhesion/migration as biological processes associated with the observed differential response in the two responder groups.

CONCLUSION:We identified genes and pathways that explain in part, and are associated with, neutralizing antibody titers after measles vaccination. This new knowledge could assist in the identification of biomarkers and predictive signatures of protective immunity that may be useful in the design of new vaccine candidates and in clinical studies.