Knowledge gaps persist and hinder progress in eliminating mumps.

Mumps, a common childhood disease in the pre-vaccine era that causes swelling of the parotid salivary glands, can lead to orchitis, viral meningitis, and sensorineural deafness. While the incidence of disease decreased dramatically after the vaccine was added to standard vaccination schedules, the disease has made a substantial resurgence in recent years. As a result, it becomes critical to examine the factors involved in recurring outbreaks. Although low and incomplete vaccination coverage may be a key reason, it does not fully explain the issue due to the high rate of occurrence in populations with high vaccination coverage rates. Multiple studies suggest that waning immunity and secondary vaccine failure play a large role, the effects of which were previously masked by subclinical boosting. Significant knowledge gaps persist around the exact role and mechanism of waning immunity and demonstrate the need for more research in this area, as well as a reevaluation of mumps vaccine policy.

Personalized vaccinology: A review.

At the current time, the field of vaccinology remains empirical in many respects. Vaccine development, vaccine immunogenicity, and vaccine efficacy have, for the most part, historically been driven by an empiric "isolate-inactivate-inject" paradigm. In turn, a population-level public health paradigm of "the same dose for everyone for every disease" model has been the normative thinking in regard to prevention of vaccine-preventable infectious diseases. In addition, up until recently, no vaccines had been designed specifically to overcome the immunosenescence of aging, consistent with a post-WWII mentality of developing vaccines and vaccine programs for children. It is now recognized that the current lack of knowledge concerning how immune responses to vaccines are generated is a critical barrier to understanding poor vaccine responses in the elderly and in immunoimmaturity, discovery of new correlates of vaccine immunogenicity (vaccine response biomarkers), and a directed approach to new vaccine development. The new fields of vaccinomics and adversomics provide models that permit global profiling of the innate, humoral, and cellular immune responses integrated at a systems biology level. This has advanced the science beyond that of reductionist scientific approaches by revealing novel interactions between and within the immune system and other biological systems (beyond transcriptional level), which are critical to developing "downstream" adaptive humoral and cellular responses to infectious pathogens and vaccines. Others have applied systems level approaches to the study of antibody responses (a.k.a. "systems serology"), [1] high-dimensional cell subset immunophenotyping through CyTOF, [2,3] and vaccine induced metabolic changes [4]. In turn, this knowledge is being utilized to better understand the following: identifying who is at risk for which infections; the level of risk that exists regarding poor immunogenicity and/or serious adverse events; and the type or dose of vaccine needed to fully protect an individual. In toto, such approaches allow for a personalized approach to the practice of vaccinology, analogous to the substantial inroads that individualized medicine is playing in other fields of human health and medicine. Herein we briefly review the field of vaccinomics, adversomics, and personalized vaccinology.

Gene signatures associated with adaptive humoral immunity following seasonal influenza A/H1N1 vaccination.

This study aimed to identify gene expression markers shared between both influenza hemagglutination inhibition (HAI) and virus-neutralization antibody (VNA) responses. We enrolled 158 older subjects who received the 2010-2011 trivalent inactivated influenza vaccine. Influenza-specific HAI and VNA titers and mRNA-sequencing were performed using blood samples obtained at Days 0, 3 and 28 post vaccination. For antibody response at Day 28 versus Day 0, several gene sets were identified as significant in predictive models for HAI (n=7) and VNA (n=35) responses. Five gene sets (comprising the genes MAZ, TTF, GSTM, RABGGTA, SMS, CA, IFNG and DOPEY) were in common for both HAI and VNA. For response at Day 28 versus Day 3, many gene sets were identified in predictive models for HAI (n=13) and VNA (n=41). Ten gene sets (comprising biologically related genes, such as MAN1B1, POLL, CEBPG, FOXP3, IL12A, TLR3, TLR7 and others) were shared between HAI and VNA. These identified gene sets demonstrated a high degree of network interactions and likelihood for functional relationships. Influenza-specific HAI and VNA responses demonstrated a remarkable degree of similarity. Although unique gene set signatures were identified for each humoral outcome, several gene sets were determined to be in common with both HAI and VNA response to influenza vaccine.

An interaction quantitative trait loci tool implicates epistatic functional variants in an apoptosis pathway in smallpox vaccine eQTL data.

Expression quantitative trait loci (eQTL) studies have functionalized nucleic acid variants through the regulation of gene expression. Although most eQTL studies only examine the effects of single variants on transcription, a more complex process of variant-variant interaction (epistasis) may regulate transcription. Herein, we describe a tool called interaction QTL (iQTL) designed to efficiently detect epistatic interactions that regulate gene expression. To maximize biological relevance and minimize the computational and hypothesis testing burden, iQTL restricts interactions such that one variant is within a user-defined proximity of the transcript (cis-regulatory). We apply iQTL to a data set of 183 smallpox vaccine study participants with genome-wide association study and gene expression data from unstimulated samples and samples stimulated by inactivated vaccinia virus. While computing only 0.15% of possible interactions, we identify 11 probe sets whose expression is regulated through a variant-variant interaction. We highlight the functional epistatic interactions among apoptosis-related genes, DIABLO, TRAPPC4 and FADD, in the context of smallpox vaccination. We also use an integrative network approach to characterize these iQTL interactions in a posterior network of known prior functional interactions. iQTL is an efficient, open-source tool to analyze variant interactions in eQTL studies, providing better understanding of the function of epistasis in immune response and other complex phenotypes.

Transcriptomic profiles of high and low antibody responders to smallpox vaccine.

Despite its eradication over 30 years ago, smallpox (as well as other orthopox viruses) remains a pathogen of interest both in terms of biodefense and for its use as a vector for vaccines and immunotherapies. Here we describe the application of mRNA-Seq transcriptome profiling to understanding immune responses in smallpox vaccine recipients. Contrary to other studies examining gene expression in virally infected cell lines, we utilized a mixed population of peripheral blood mononuclear cells in order to capture the essential intercellular interactions that occur in vivo, and would otherwise be lost, using single cell lines or isolated primary cell subsets. In this mixed cell population we were able to detect expression of all annotated vaccinia genes. On the host side, a number of genes encoding cytokines, chemokines, complement factors and intracellular signaling molecules were downregulated upon viral infection, whereas genes encoding histone proteins and the interferon response were upregulated. We also identified a small number of genes that exhibited significantly different expression profiles in subjects with robust humoral immunity compared with those with weaker humoral responses. Our results provide evidence that differential gene regulation patterns may be at work in individuals with robust humoral immunity compared with those with weaker humoral immune responses.

[Does patient safety justify mandatory vaccinations?]. / Rechtfertigt der Patientenschutz verpflichtende Impfungen?

BACKGROUND AND OBJECTIVES: Medical and dental students belong to a group of health care workers (HCWs) who are frequently exposed to patients with occupationally transmissible infectious diseases. Vaccinations are the most effective interventions to protect HCWs and patients from vaccine-preventable infectious diseases. Despite decades of effort to encourage HCWs to be immunized, vaccination levels (e. g. influenza) remain insufficient. METHODS: To assess the attitudes of German medical and dental students towards mandatory immunizations, an anonymous questionnaire was offered to medical and dental students of the University of Frankfurt/Main, Germany. Overall, 56.9 % (1823/3200) of all medical and dental students attended to the study. RESULTS: This study - so far the largest study done on this issue - showed that almost 88.5 % of the responding medical and dental students would accept mandatory vaccinations for HCWs. CONCLUSION: Contrary to the widespread concern that a vaccination requirement would cause resistance, our data support that mandatory vaccinations (at least for HCWs who care for immunocompromised patients) might be widely accepted.

The role of HLA-DR-DQ haplotypes in variable antibody responses to anthrax vaccine adsorbed.

Host genetic variation, particularly within the human leukocyte antigen (HLA) loci, reportedly mediates heterogeneity in immune response to certain vaccines; however, no large study of genetic determinants of anthrax vaccine response has been described. We searched for associations between the immunoglobulin G antibody to protective antigen (AbPA) response to Anthrax Vaccine Adsorbed (AVA) in humans, and polymorphisms at HLA class I (HLA-A, -B, and -C) and class II (HLA-DRB1, -DQA1, -DQB1, -DPB1) loci. The study included 794 European-Americans and 200 African-Americans participating in a 43-month, double-blind and placebo-controlled clinical trial of AVA (clinicaltrials.gov identifier NCT00119067). Among European-Americans, genes from tightly linked HLA-DRB1, -DQA1, -DQB1 haplotypes displayed significant overall associations with longitudinal variation in AbPA levels at 4, 8, 26 and 30 weeks from baseline in response to vaccination with three or four doses of AVA (global P=6.53 × 10(-4)). In particular, carriage of the DRB1-DQA1-DQB1 haplotypes (*)1501-(*)0102-(*)0602 (P=1.17 × 10(-5)), (*)0101-(*)0101-(*)0501 (P=0.009) and (*)0102-(*)0101-(*)0501 (P=0.006) was associated with significantly lower AbPA levels. In carriers of two copies of these haplotypes, lower AbPA levels persisted following subsequent vaccinations. No significant associations were observed amongst African-Americans or for any HLA class I allele/haplotype. Further studies will be required to replicate these findings and to explore the role of host genetic variation outside of the HLA region.

An assessment of the association between childhood asthma and HLA DRB1*03 using extended haplotype analysis.

Ancestral haplotypes between human leukocyte antigen (HLA) class I and class II alleles are well-recognized in the literature. We previously published a positive association between the class II HLA allele DRB1*03 and the subsequent development of asthma in a retrospective cohort of 383 children. To refine this association, we investigated whether DRB1*03-specific haplotypes extending across the HLA are associated with asthma incidence. We found evidence of strong HLA DRB1*03-dependent linkage disequilibrium across the region, but no association between DRB1*03 ancestral haplotypes and childhood asthma. We did, however, observe a trend toward a positive association between HLA DRB1*03 and asthma by adding non-ancestral DRB1*03 positive haplotypes. Our results suggest that the role of the HLA DRB1*03 in asthma susceptibility is independent of ancestral-haplotype-mediated linkage disequilibrium.

Associations between cytokine/cytokine receptor single nucleotide polymorphisms and humoral immunity to measles, mumps and rubella in a Somali population.

We genotyped a Somali population (n = 85; age < or =30 years) for 617 cytokine and cytokine receptor single nucleotide polymorphisms (SNPs) using Illumina GoldenGate genotyping to determine associations with measles, mumps and rubella immunity. Overall, 61 significant associations (P < or = 0.01) were found between SNPs belonging to cytokine receptor genes regulating T helper (Th)1 (IL12RB2, IL2RA and B) and Th2 (IL4R and IL10RB) immunity, and cytokine (IL1B, TNFA, IL6 and IFNB1) and cytokine receptor (IL1RA, IFNAR2, IL18R1, TNFRSF1A and B) genes regulating innate immunity and variations in antibody levels to measles, mumps and/or rubella. SNPs within two major inflammatory cytokine genes, TNFA and interleukin (IL) 6, showed associations with measles-specific antibodies. Specifically, the minor allele variant of rs1799964 (TNFA -1211 C>T) was associated with primarily seronegative values (median enzyme immunoassay index values < or =0.87; P = 0.002; q = 0.23) in response to measles disease and/or vaccination. A heterozygous variant CT for rs2069849 (IL6 +4272C>T; Phe201Phe) was also associated with seronegative values and a lower median level of antibody response to measles disease and/or vaccination (P = 0.004; q = 0.36) or measles vaccination alone (P = 0.008). Several SNPs within the coding and regulatory regions of cytokine and cytokine receptor genes showed associations with mumps and rubella antibody levels but were less informative as strong linkage disequilibrium patterns and lower frequencies for minor alleles were observed among these SNPs. Our study identifies specific SNPs in innate immune response genes that may play a role in modulating antibody responses to measles vaccination and/or infection in Somali subjects.

Heterogeneity in vaccine immune response: the role of immunogenetics and the emerging field of vaccinomics.

Recent advances in the fields of immunology, genetics, molecular biology, bioinformatics, and the Human Genome Project have allowed for the emergence of the field of vaccinomics. Vaccinomics encompasses the fields of immunogenetics and immunogenomics as applied to understanding the mechanisms of heterogeneity in immune responses to vaccines. In this study, we examine the role of HLA genes, cytokine genes, and cell surface receptor genes as examples of how genetic polymorphism leads to individual and population variations in immune responses to vaccines. In turn, this data, in concert with new high-throughput technology, inform the immune-response network theory to vaccine response. Such information can be used in the directed and rational development of new vaccines, and this new golden age of vaccinology has been termed "predictive vaccinology", which will predict the likelihood of a vaccine response or an adverse response to a vaccine, the number of doses needed and even whether a vaccine is likely to be of benefit (i.e., is the individual at risk for the outcome for which the vaccine is being administered?).

White blood cell telomerase activity and incident respiratory illness among community-dwelling elderly vaccinated against seasonal influenza.

Immune cell telomerase activity may impact vaccine response in the elderly. Fifty persons aged 60-100 years were tested for post-influenza vaccination telomerase RNA expression (TERT) in peripheral blood mononuclear cells to assess for an association with influenza antibody levels and influenza-like illness or incident respiratory infection (IRI) in the year following vaccination. High rates of seroprotective influenza antibody (> or = 1:40 titers) were observed post-vaccination (86-92% to vaccine viral strains), with no association to TERT. No IRI occurred among persons in the top quartile of TERT expression, whereas the IRI rate was 33% in the lower three quartiles (Kaplan-Meier P=0.028). TERT expression was also IRI significantly higher in those who did not experience IRI than those who did in the follow-up period (0.845 vs. 0.301, P=0.024). These data suggest that telomerase expression may correlate with immune capacity for vaccine response in the elderly and could represent a target for recognizing risk for vaccine failure.

Mass spectrometry and peptide-based vaccine development.

The development of new vaccines against pathogens is an important part of infectious disease control. In the last decade, a variety of proteins giving rise to naturally processed pathogen-derived antigenic peptides, representing B-cell and T-cell epitopes, have been characterized. Numerous candidate vaccines consisting of synthetic peptides are being designed and evaluated, with encouraging results. In this context, the application of mass spectrometry based on the isolation and identification of pathogen-derived peptides from the human leukocyte antigen (HLA) molecules is a major focus of peptide-based vaccine development. Dramatic improvements have been made in mass spectrometer performance for peptide sequencing in terms of increased sensitivity, the ability to rapidly obtain data-directed tandem mass spectra, and the accuracy of mass measurement. This review focuses on the efforts to identify T-cell epitopes for viral and microbial pathogens for directed vaccine development.

Childhood asthma and human leukocyte antigen type.

Little is known about the relationship between human leukocyte antigen (HLA) class II genes and family history of asthma or atopy in relation to the incidence of childhood asthma. The objective of the study was to determine whether specific HLA class II genes (e.g., DRB1*03) are associated with asthma and whether such association explains the influences of family history of asthma or atopy on asthma incidence. A stratified random sample of 340 children who had HLA data available from the Rochester Family Measles Study cohort (n= 876) and a convenience sample of healthy children aged 5-12 years were the participants. We conducted comprehensive medical record reviews to determine asthma status of these children. The associations between the presence of specific HLA alleles and development of asthma and the role of family history of asthma or atopy in the association were evaluated by fitting Cox models. The cumulative incidence of asthma by 12 years of age among children who carry HLA DRB1*03 was 33%, compared to 24.2% among those who did not carry this allele. Adjusting for family history of asthma or atopy, gender, low birth weight, season of birth, HLA DRB1*04, and HLA DQB1*0302, the hazards ratio for HLA DRB1*03 carriers was 1.8 (95% confidence interval: 1.1-2.9, P= 0.020). We concluded that the HLA DRB1*03 allele is associated with asthma. However, the HLA class II gene does not explain the influences of family history of asthma or atopy on development of asthma. The mechanism underlying the association between asthma and HLA genes needs to be elucidated.

Inter-operator variation in ELISPOT analysis of measles virus-specific IFN-gamma-secreting T cells.

The ELISPOT assay is a highly sensitive technique used for the detection of individual cytokine releasing cells. We have developed an IFN-gamma ELISPOT assay utilizing unfractionated frozen peripheral blood mononuclear cells (PBMC) to quantify the frequency of measles virus (MV)-specific IFN-gamma-secreting T cells in 117 healthy children who had been previously immunized with two doses of the measles-mumps-rubella vaccine. We have also estimated the variability associated with the quantification of ELISPOT plates and compared the number of MV-specific IFN-gamma-secreting T cells for each subject as determined by two different operators of an ELISPOT reader. The median frequency of MV-specific IFN-gamma-producing memory T cells detected by this assay was 0.005 % and 0.01 % as determined by an in-house and commercial operator, respectively. Although we found a significant correlation (r = 0.83, p<0.0001) between the number of spots counted by the commercial and in-house operators of an ELISPOT reader, the median number of spots counted by the commercial operator was twice the number of spots counted by an in-house operator (p<0.001). This demonstrates the importance of using a common ELISPOT reader and operator, among other parameters, to quantify the number of spots when a large volume of plates are being scanned and analyzed.