Associations between human leukocyte antigen (HLA) alleles and very high levels of measles antibody following vaccination

Genetics and measles, mumps and rubella vaccine response in childhood and adolescence-A systematic review

Measles, mumps and rubella (MMR) are contagious infectious diseases that can be prevented by immunization. However, MMR infections can occur in previously immunized individuals. The vaccine response is, among other factors, influenced by the combined effects of many genes. This systematic review investigates the genetic influence on measles, mumps and rubella antibody responses after childhood vaccination. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), systematic literature searches were conducted in the medical databases PubMed, EMBASE and PsycINFO. Search strings were adjusted for each database. Citations were included if they measured and compared the immune response with immunogenetics after vaccination with a vaccine containing one or more of the following components: measles, mumps and/or rubella, MMR. The measure of vaccine response studied was antibodies after vaccination. Forty-eight articles were included in the final analysis. The results suggest that genetic determinants, including host genes, and single nucleotide polymorphisms in immune-related genes influence the MMR antibody responses after vaccination. Specifically, replicated associations were found between HLA, CD46, RARB, IRF9, EIF2AK2, cytokine genes and MMR vaccine-induced humoral immune responses. This knowledge can be useful in understanding and predicting immune responses and may have implications for future vaccine strategies.

Vaccinomics: A scoping review

BACKGROUND

This scoping review summarizes a key aspect of vaccinomics by collating known associations between heterogeneity in human genetics and vaccine immunogenicity and safety.

METHODS

We searched PubMed for articles in English using terms covering vaccines routinely recommended to the general US population, their effects, and genetics/genomics. Included studies were controlled and demonstrated statistically significant associations with vaccine immunogenicity or safety. Studies of Pandemrix®, an influenza vaccine previously used in Europe, were also included, due to its widely publicized genetically mediated association with narcolepsy.

FINDINGS

Of the 2,300 articles manually screened, 214 were included for data extraction. Six included articles examined genetic influences on vaccine safety; the rest examined vaccine immunogenicity. Hepatitis B vaccine immunogenicity was reported in 92 articles and associated with 277 genetic determinants across 117 genes. Thirty-three articles identified 291 genetic determinants across 118 genes associated with measles vaccine immunogenicity, 22 articles identified 311 genetic determinants across 110 genes associated with rubella vaccine immunogenicity, and 25 articles identified 48 genetic determinants across 34 genes associated with influenza vaccine immunogenicity. Other vaccines had fewer than 10 studies each identifying genetic determinants of their immunogenicity. Genetic associations were reported with 4 adverse events following influenza vaccination (narcolepsy, GBS, GCA/PMR, high temperature) and 2 adverse events following measles vaccination (fever, febrile seizure).

CONCLUSION

This scoping review identified numerous genetic associations with vaccine immunogenicity and several genetic associations with vaccine safety. Most associations were only reported in one study. This illustrates both the potential of and need for investment in vaccinomics. Current research in this field is focused on systems and genetic-based studies designed to identify risk signatures for serious vaccine reactions or diminished vaccine immunogenicity. Such research could bolster our ability to develop safer and more effective vaccines.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

A large population-based association study between HLA and KIR genotypes and measles vaccine antibody responses

Human antibody response to measles vaccine is highly variable in the population. Host genes contribute to inter-individual antibody response variation. The killer cell immunoglobulin-like receptors (KIR) are recognized to interact with HLA molecules and possibly influence humoral immune response to viral antigens. To expand on and improve our previous work with HLA genes, and to explore the genetic contribution of KIR genes to the inter-individual variability in measles vaccine-induced antibody responses, we performed a large population-based study in 2,506 healthy immunized subjects (ages 11 to 41 years) to identify HLA and KIR associations with measles vaccine-induced neutralizing antibodies. After correcting for the large number of statistical tests of allele effects on measles-specific neutralizing antibody titers, no statistically significant associations were found for either HLA or KIR loci. However, suggestive associations worthy of follow-up in other cohorts include B*57:01, DQB1*06:02, and DRB1*15:05 alleles. Specifically, the B*57:01 allele (1,040 mIU/mL; p = 0.0002) was suggestive of an association with lower measles antibody titer. In contrast, the DQB1*06:02 (1,349 mIU/mL; p = 0.0004) and DRB1*15:05 (2,547 mIU/mL; p = 0.0004) alleles were suggestive of an association with higher measles antibodies. Notably, the associations with KIR genotypes were strongly nonsignificant, suggesting that KIR loci in terms of copy number and haplotypes are not likely to play a major role in antibody response to measles vaccination. These findings refine our knowledge of the role of HLA and KIR alleles in measles vaccine-induced immunity.

Predicting vaccine responsiveness

Vaccination has saved many lives and prevented needless suffering from disease, but it is not always effective. Immune responses are a highly "personalized" aspect of an individual's biology, as they are subject to germline genetic influences but are embodied in cell populations that continuously sample the environment. Additionally, immunity is shaped by memory of prior infectious diseases and other antigenic exposures. Here, we review examples of recent technical advances and insights into human vaccine responses that are helping to define the features associated with successful vaccination and that may enable a more predictive vaccinology in the future.

Variability in Humoral Immunity to Measles Vaccine: New Developments

Despite the existence of an effective measles vaccine, resurgence in measles cases in the USA and across Europe has occurred, including in individuals vaccinated with two doses of the vaccine. Host genetic factors result in inter-individual variation in measles vaccine-induced antibodies, and play a role in vaccine failure. Studies have identified HLA (human leukocyte antigen) and non-HLA genetic influences that individually or jointly contribute to the observed variability in the humoral response to vaccination among healthy individuals. In this exciting era, new high-dimensional approaches and techniques including vaccinomics, systems biology, GWAS, epitope prediction and sophisticated bioinformatics/statistical algorithms provide powerful tools to investigate immune response mechanisms to the measles vaccine. These might predict, on an individual basis, outcomes of acquired immunity post measles vaccination.

Comprehensive Analysis of the Naturally Processed Peptide Repertoire: Differences between HLA-A and B in the Immunopeptidome

The cytotoxic T cell (CTL) response is determined by the peptide repertoire presented by the HLA class I molecules of an individual. We performed an in-depth analysis of the peptide repertoire presented by a broad panel of common HLA class I molecules on four B lymphoblastoid cell-lines (BLCL). Peptide elution and mass spectrometry analysis were utilised to investigate the number and abundance of self-peptides. Altogether, 7897 unique self-peptides, derived of 4344 proteins, were eluted. After viral infection, the number of unique self-peptides eluted significantly decreased compared to uninfected cells, paralleled by a decrease in the number of source proteins. In the overall dataset, the total number of unique self-peptides eluted from HLA-B molecules was larger than from HLA-A molecules, and they were derived from a larger number of source proteins. These results in B cells suggest that HLA-B molecules possibly present a more diverse repertoire compared to their HLA-A counterparts, which may contribute to their immunodominance. This study provides a unique data set giving new insights into the complex system of antigen presentation for a broad panel of HLA molecules, many of which were never studied this extensively before.

HLA alleles associated with the adaptive immune response to smallpox vaccine: a replication study

We previously reported HLA allelic associations with vaccinia virus (VACV)-induced adaptive immune responses in a cohort of healthy individuals (n = 1,071 subjects) after a single dose of the licensed smallpox (Dryvax) vaccine. This study demonstrated that specific HLA alleles were significantly associated with VACV-induced neutralizing antibody (NA) titers (HLA-B*13:02, *38:02, *44:03, *48:01, and HLA-DQB1*03:02, *06:04) and cytokine (HLA-DRB1*01:03, *03:01, *10:01, *13:01, *15:01) immune responses. We undertook an independent study of 1,053 healthy individuals and examined associations between HLA alleles and measures of adaptive immunity after a single dose of Dryvax-derived ACAM2000 vaccine to evaluate previously discovered HLA allelic associations from the Dryvax study and determine if these associations are replicated with ACAM2000. Females had significantly higher NA titers than male subjects in both study cohorts [median ID50 discovery cohort 159 (93, 256) vs. 125 (75, 186), p < 0.001; replication cohort 144 (82, 204) vs. 110 (61, 189), p = 0.024]. The association between the DQB1*03:02 allele (median ID50 discovery cohort 152, p = 0.015; replication cohort 134, p = 0.010) and higher NA titers was replicated. Two HLA associations of comparable magnitudes were consistently found between DRB1*04:03 and DRB1*08:01 alleles and IFN-γ ELISPOT responses. The association between the DRB1*15:01 allele with IFN-γ secretion was also replicated (median pg/mL discovery cohort 182, p = 0.052; replication cohort 203, p = 0.014). Our results suggest that smallpox vaccine-induced adaptive immune responses are significantly influenced by HLA gene polymorphisms. These data provide information for functional studies and design of novel candidate smallpox vaccines.

Association of HLA alleles with the responsiveness to hepatitis B virus vaccination in Korean infants

Hepatitis B virus (HBV) vaccination is the most effective means of countering HBV-related morbidity and mortality, and individuals who do not respond to vaccination (non-responders) are problematic. The aim of the present study was to investigate associations between HLA and responsiveness to HBV vaccine in Korean infants. A total of 944 healthy Korean infants 9-12 months old were enrolled, and HLA distribution was compared among subgroups in accordance with the response to HBV vaccination. The HLA distribution of the subjects was similar to known Korean population data and did not deviate from the HWE proportions. The alleles that showed positive associations with non-responsiveness (<10mIU/mL) or low antibody titer (<100mIU/mL) were HLA-A*33, B62, DRB1*04, and DRB1*07, while the alleles A*02 and DRB1*08 showed negative associations. Among these alleles, B62, DRB1*07 and DRB1*08(-) showed significant associations with a poor or decreased response to vaccination even after correction (OR=1.83, 1.99, 5.63; pc<0.05) and also showed dose effects. After stratification by other associated alleles at different loci, B62 and DRB1*07 were independently associated with non-responsiveness, but A*02(-) and DRB1*08(-) lost their individual associations. The combined association of A*02(-)-DRB1*08(-) and B62-DRB1*08(-) was significant (OR=25.2 and 24.5; pc<0.05). Although the hierarchy is not clear, we can assume the following: (i) B62 and DRB1*07 have independent effects, (ii) DRB1*08(-) has a very strong and synergic effect, and (iii) there is probability of a third factor controlling A*02(-) and DRB1*08(-) with an effect on non-responsiveness to HBV vaccination in Korean infants.

HLA genotypes and rubella vaccine immune response: additional evidence

Recent population-based studies have demonstrated the genetic heritability of rubella vaccine response and assessed that the HLA system may explain about 20% of the inter-individual variance in humoral immune response to this vaccine. Our earlier studies compared HLA allelic associations with rubella vaccine-specific antibodies between two smaller cohorts of healthy Rochester, MN, children (346 and 396 subjects) after two doses of rubella-containing vaccine. This study found that specific HLA alleles were consistently associated with rubella-specific antibody titers (B*27:05, DPA1*02:01, and DPB1*04:01 alleles). The current study examined HLA associations in an independent larger cohort of 1012 healthy San Diego, CA, subjects (age 19-40 years) after rubella vaccine in order to replicate our previous findings in the Rochester subjects. Two HLA associations of comparable magnitudes were consistently observed between B*27:05 (median NT50 Rochester cohort 48.9, p=0.067; San Diego cohort 54.8, p=0.047) and DPB1*04:01 (median NT50 Rochester cohort 61.6, p<0.001; San Diego cohort 70.8, p=0.084) alleles and rubella virus-neutralizing antibody titers. Additional HLA alleles resulted in consistent effects on IL-6 production in both cohorts, but did not meet criteria for statistical significance. Our data suggest these HLA alleles play a role in rubella vaccine-induced immunity and provide the basis for future studies that may explain the mechanism(s) by which these HLA polymorphisms affect immune responses to rubella vaccine.

Immunological assessment of influenza vaccines and immune correlates of protection

Influenza vaccines remain the primary public health tool in reducing the ever-present burden of influenza and its complications. In seeking more immunogenic, more effective and more broadly cross-protective influenza vaccines, the landscape of influenza vaccines is rapidly expanding, both in near-term advances and next-generation vaccine design. Although the first influenza vaccines were licensed over 60 years ago, the hemagglutination-inhibition antibody titer is currently the only universally accepted immune correlate of protection against influenza. However, hemagglutination-inhibition titers appear to be less effective at predicting protection in populations at high risk for severe influenza disease; older adults, young children and those with certain medical conditions. The lack of knowledge and validated methods to measure alternate immune markers of protection against influenza remain a substantial barrier to the development of more immunogenic, broadly cross-reactive and effective influenza vaccines. Here, the authors review the knowledge of immune effectors of protection against influenza and discuss assessment methods for a broader range of immunological parameters that could be considered in the evaluation of traditional or new-generation influenza vaccines.

The genetic basis for interindividual immune response variation to measles vaccine: new understanding and new vaccine approaches

The live-attenuated measles vaccine is effective, but measles outbreaks still occur in vaccinated populations. This warrants elucidation of the determinants of measles vaccine-induced protective immunity. Interindividual variability in markers of measles vaccine-induced immunity, including neutralizing antibody levels, is regulated in part by host genetic factor variations. This review summarizes recent advances in our understanding of measles vaccine immunogenetics relative to the perspective of developing better measles vaccines. Important genetic regulators of measles vaccine-induced immunity, such as HLA class I and HLA class II genotypes, single nucleotide polymorphisms in cytokine/cytokine receptor genes (IL12B, IL12RB1, IL2, IL10) and the cell surface measles virus receptor CD46 gene, have been identified and independently replicated. New technologies present many opportunities for identification of novel genetic signatures and genetic architectures. These findings help explain a variety of immune response-related phenotypes and promote a new paradigm of 'vaccinomics' for novel vaccine development.

Imaging of the skeletal muscle metastases

Preclinical Research

Copyright 2011 Wiley-Liss, Inc., A Wiley CompanyThis article is being made freely available through PubMed Central as part of the COVID-19 public health emergency response. It can be used for unrestricted research re-use and analysis in any form or by any means with acknowledgement of the original source, for the duration of the public health emergency.

Omics technologies include genomics, transcriptomics, proteomics, metabolomics, and immunomics. These technologies have been used in vaccine research, which can be summarized using the term “vaccinomics.” These omics technologies combined with advanced bioinformatics analysis form the core of “systems vaccinology.” Omics technologies provide powerful methods in vaccine target identification. The genomics‐based reverse vaccinology starts with predicting vaccine protein candidates through in silico bioinformatics analysis of genome sequences. The VIOLIN Vaxign vaccine design program (http://www.violinet.org/vaxign) is the first web‐based vaccine target prediction software based on the reverse vaccinology strategy. Systematic transcriptomics and proteomics analyses facilitate rational vaccine target identification by detesting genome‐wide gene expression profiles. Immunomics is the study of the set of antigens recognized by host immune systems and has also been used for efficient vaccine target prediction. With the large amount of omics data available, it is necessary to integrate various vaccine data using ontologies, including the Gene Ontology (GO) and Vaccine Ontology (VO), for more efficient vaccine target prediction and assessment. All these omics technologies combined with advanced bioinformatics analysis methods for a systems biology‐based vaccine target prediction strategy. This article reviews the various omics technologies and how they can be used in vaccine target identification.

Toxicogenomic profiles in relation to maternal immunotoxic exposure and immune functionality in newborns

A crucial period for the development of the immune system occurs in utero. This results in a high fetal vulnerability to immunotoxic exposure, and indeed, immunotoxic effects have been reported, demonstrating negative effects on immune-related health outcomes and immune functionality. Within the NewGeneris cohort BraMat, a subcohort of the Norwegian Mother and Child Cohort Study (MoBa), immunotoxicity was demonstrated for polychlorinated biphenyls and dioxins, showing associations between estimated maternal intake levels and reduced measles vaccination responses in the offspring at the age of 3. The present study aimed to investigate this link at the transcriptomic level within the same BraMat cohort. To this end, whole-genome gene expression in cord blood was investigated and found to be associated with maternal Food Frequency Questionnaires-derived exposure estimates and with vaccination responses in children at 3 years of age. Because the literature reports gender specificity in the innate, humoral, and cell-mediated responses to viral vaccines, separate analysis for males and females was conducted. Separate gene sets for male and female neonates were identified, comprising genes significantly correlating with both 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and polychlorinated biphenyls (PCB) exposure and with measles vaccination response. Noteworthy, genes correlating negatively with exposure in general show positive correlations with antibody levels and vice versa. For both sexes, these included immune-related genes, suggesting immunosuppressive effects of maternal exposure to TCDD and PCB at the transcriptomic level in neonates in relation to measles vaccination response 3 years later.

Gene polymorphism in toll-like receptor 4: effect on antibody production and persistence after acellular pertussis vaccination during adolescence

BACKGROUND

Toll-like receptors play an important role in the regulation of adaptive immunity. This study aimed to investigate whether Toll-like receptor 4 (TLR4) polymorphisms influence the production and persistence of antibodies after acellular pertussis booster vaccination during adolescence.

METHODS

Seventy-five subjects received a single dose of diphtheria and tetanus toxoids and acellular pertussis vaccine 10 years ago, during adolescence. The same cohort was followed up at 3, 5, and 10 years after this booster vaccination. Pyrosequencing was used for detecting polymorphism in TLR4. Concentrations of anti-pertussis vaccine antibodies were measured by standardized enzyme-linked immunosorbant assay and published elsewhere.

RESULTS

The fold increase in antibodies to pertussis toxin after original vaccination 10 years ago was significantly lower in subjects with TLR4 polymorphism than in those without (55% vs 86%; P = .028). At the 3-year follow-up evaluation, geometric mean concentrations of anti-pertussis vaccine antibodies were significantly lower in subjects with TLR4 polymorphism, compared with those without the polymorphism (for pertussis toxin, P = .028; for filamentous hemagglutinin, P = .047; and for pertactin, P = .046).

CONCLUSIONS

This study suggests that TLR4 Asp299Gly polymorphism might influence production and persistence of antibodies after pertussis booster vaccination in adolescents. However, the results should be interpreted with caution as the number of subjects included in this study was limited.

Associations between demographic variables and multiple measles-specific innate and cell-mediated immune responses after measles vaccination

Measles remains a public health concern due to a lack of vaccine use and vaccine failure. A better understanding of the factors that influence variations in immune responses, including innate/inflammatory and adaptive cellular immune responses, following measles-mumps-rubella (MMR) vaccination could increase our knowledge of measles vaccine-induced immunity and potentially lead to better vaccines. Measles-specific innate/inflammatory and adaptive cell-mediated immune (CMI) responses were characterized using enzyme-linked immunosorbent assays to quantify the levels of secreted IL-2, IL-6, IL-10, IFN-α, IFN-γ, IFN-λ1, and TNF-α in PBMC cultures following in vitro stimulation with measles virus (MV) in a cohort of 764 school-aged children. IFN-γ ELISPOT assays were performed to ascertain the number of measles-specific IFN-γ-secreting cells. Cytokine responses were then tested for associations with self-declared demographic data, including gender, race, and ethnicity. Females secreted significantly more TNF-α, IL-6, and IFN-α (p<0.001, p<0.002, p<0.04, respectively) compared to males. Caucasians secreted significantly more IFN-λ1, IL-10, IL-2, TNF-α, IL-6, and IFN-α (p<0.001, p<0.001, p<0.001, p<0.003, p<0.01, and p<0.02, respectively) compared to the other racial groups combined. Additionally, Caucasians had a greater number of IFN-γ-secreting cells compared to other racial groups (p<0.001). Ethnicity was not significantly correlated with variations in measles-specific CMI measures. Our data suggest that innate/inflammatory and CMI cytokine responses to measles vaccine vary significantly by gender and race. These data further advance our understanding regarding inter-individual and subgroup variations in immune responses to measles vaccination.

Vaccinomics: current findings, challenges and novel approaches for vaccine development

Recent years have witnessed a growing interest in a field of vaccinology that we have named vaccinomics. The overall idea behind vaccinomics is to identify genetic and other mechanisms and pathways that determine immune responses, and thereby provide new candidate vaccine approaches. Considerable data show that host genetic polymorphisms act as important determinants of innate and adaptive immunity to vaccines. This review highlights examples of the role of immunogenetics and immunogenomics in understanding immune responses to vaccination, which are highly variable across the population. The influence of HLA genes, non-HLA, and innate genes in inter-individual variations in immune responses to viral vaccines are examined using population-based gene/SNP association studies. The ability to understand relationships between immune response gene variants and vaccine-specific immunity may assist in designing new vaccines. At the same time, application of state-of-the-art next-generation sequencing technology (and bioinformatics) is desired to provide new genetic information and its relationship to the immune response.

Vaccinomics and a new paradigm for the development of preventive vaccines against viral infections

In this article we define vaccinomics as the integration of immunogenetics and immunogenomics with systems biology and immune profiling. Vaccinomics is based on the use of cutting edge, high-dimensional (so called "omics") assays and novel bioinformatics approaches to the development of next-generation vaccines and the expansion of our capabilities in individualized medicine. Vaccinomics will allow us to move beyond the empiric "isolate, inactivate, and inject" approach characterizing past vaccine development efforts, and toward a more detailed molecular and systemic understanding of the carefully choreographed series of biological processes involved in developing viral vaccine-induced "immunity." This enhanced understanding will then be applied to overcome the obstacles to the creation of effective vaccines to protect against pathogens, particularly hypervariable viruses, with the greatest current impact on public health. Here we provide an overview of how vaccinomics will inform vaccine science, the development of new vaccines and/or clinically relevant biomarkers or surrogates of protection, vaccine response heterogeneity, and our understanding of immunosenescence.

Human leukocyte antigen associations with humoral and cellular immunity following a second dose of measles-containing vaccine: persistence, dampening, and extinction of associations found after a first dose

Previously we found human leukocyte antigen (HLA) associations with humoral immunity following a single dose of measles-containing vaccine. In this study, we sought to determine if HLA associations exist with humoral and cellular immunity following a second dose of measles-containing vaccine and if the associations we found with humoral immunity after the first dose persist following a second dose. We recruited a population-based sample of 346 schoolchildren, all who previously received two doses of a measles-containing vaccine. Molecular HLA classes I and II typing as well as humoral and cellular immune assays (measles-specific IgG antibody levels and lymphoproliferative response) were performed in these subjects. We found significant associations with class I HLA-B (p=0.05) as well as class II HLA-DPB1 (p=0.01) and -DPA1 (p=0.03) genes for measles vaccine-induced antibody levels after the second dose. Similarly, we found significant associations with class II HLA-DQB1 (p=0.05) and -DRB1 (p=0.01) genes for measles-specific lymphoproliferation after the second dose. While we found HLA associations after the second dose that we previously found after the first dose of measles containing vaccine, fewer alleles had statistically significant associations, suggesting that the second dose had a dampening or extinguishing effect on the HLA associations. It appears that the second dose overcomes HLA restriction through an as yet unknown mechanism. Future studies of HLA associations should consider both the effect of dose and the role that subsequent doses might play on genetic associations found with the response to a first dose.

Application of pharmacogenomics to vaccines

The field of pharmacogenomics and pharmacogenetics provides a promising science base for vaccine research and development. A broad range of phenotype/genotype data combined with high-throughput genetic sequencing and bioinformatics are increasingly being integrated into this emerging field of vaccinomics. This paper discusses the hypothesis of the 'immune response gene network' and genetic (and bioinformatic) strategies to study associations between immune response gene polymorphisms and variations in humoral and cellular immune responses to prophylactic viral vaccines, such as measles-mumps-rubella, influenza, HIV, hepatitis B and smallpox. Immunogenetic studies reveal promising new vaccine targets by providing a better understanding of the mechanisms by which gene polymorphisms may influence innate and adaptive immune responses to vaccines, including vaccine failure and vaccine-associated adverse events. Additional benefits from vaccinomic studies include the development of personalized vaccines, the development of novel vaccines and the development of novel vaccine adjuvants.

Clear and independent associations of several HLA-DRB1 alleles with differential antibody responses to hepatitis B vaccination in youth

To confirm and refine associations of human leukocyte antigen (HLA) genotypes with variable antibody (Ab) responses to hepatitis B vaccination, we have analyzed 255 HIV-1 seropositive (HIV⁺) youth and 80 HIV-1 seronegatives (HIV⁻) enrolled into prospective studies. In univariate analyses that focused on HLA-DRB1, -DQA1, and -DQB1 alleles and haplotypes, the DRB1*03 allele group and DRB1*0701 were negatively associated with the responder phenotype (serum Ab concentration ≥ 10 mIU/mL) (P = 0.026 and 0.043, respectively). Collectively, DRB1*03 and DRB1*0701 were found in 42 (53.8%) out of 78 non-responders (serum Ab <10 mIU/mL), 65 (40.6%) out of 160 medium responders (serum Ab 10–1,000 mIU/mL), and 27 (27.8%) out of 97 high responders (serum Ab >1,000 mIU/mL) (P < 0.001 for trend). Meanwhile, DRB1*08 was positively associated with the responder phenotype (P = 0.010), mostly due to DRB1*0804 (P = 0.008). These immunogenetic relationships were all independent of non-genetic factors, including HIV-1 infection status and immunodeficiency. Alternative analyses confined to HIV⁺ youth or Hispanic youth led to similar findings. In contrast, analyses of more than 80 non-coding, single nucleotide polymorphisms within and beyond the three HLA class II genes revealed no clear associations. Overall, several HLA-DRB1 alleles were major predictors of differential Ab responses to hepatitis B vaccination in youth, suggesting that T-helper cell-dependent pathways mediated through HLA class II antigen presentation are critical to effective immune response to recombinant vaccines.

HLA and infectious diseases

Following their discovery in the early 1970s, classical human leukocyte antigen (HLA) loci have been the prototypical candidates for genetic susceptibility to infectious disease. Indeed, the original hypothesis for the extreme variability observed at HLA loci (H-2 in mice) was the major selective pressure from infectious diseases. Now that both the human genome and the molecular basis of innate and acquired immunity are understood in greater detail, do the classical HLA loci still stand out as major genes that determine susceptibility to infectious disease? This review looks afresh at the evidence supporting a role for classical HLA loci in susceptibility to infectious disease, examines the limitations of data reported to date, and discusses current advances in methodology and technology that will potentially lead to greater understanding of their role in infectious diseases in the future.

Personalized vaccines: the emerging field of vaccinomics

The next 'golden age' in vaccinology will be ushered in by the new science of vaccinomics. In turn, this will inform and allow the development of personalized vaccines, based on our increasing understanding of immune response phenotype: genotype information. Rapid advances in developing such data are already occurring for hepatitis B, influenza, measles, mumps, rubella, anthrax and smallpox vaccines. In addition, newly available data suggest that some vaccine-related adverse events may also be genetically determined and, therefore, predictable. This paper reviews the basis and logic of personalized vaccines, and describes recent advances in the field.

Vaccine immunogenetics: bedside to bench to population

The immunogenetic basis for variations in immune response to vaccines in humans remains largely unknown. Many factors can contribute to the heterogeneity of vaccine-induced immune responses, including polymorphisms of immune response genes. It is important to identify those genes involved directly or indirectly in the generation of the immune response to vaccines. Our previous work with measles reveals the impact of immune response gene polymorphisms on measles vaccine-induced humoral and cellular immune responses. We demonstrate associations between genetic variations (single nucleotide polymorphisms, SNPs) in HLA class I and class II genes, cytokine, cell surface receptor, and toll-like receptor genes and variations in immune responses to measles vaccine. Such information may provide further understanding of genetic restrictions that influence the generation of protective immune responses to vaccines, and eventually the development of new vaccines.

Measles vaccination: new strategies and formulations

Measles is a highly contagious viral disease. With 1 million deaths reported in 1996, measles was the leading cause of vaccine-preventable deaths. However, in recent years, significant progress has been made in measles control, reducing deaths attributed to measles to 454,000 in 2004 and 242,000 in 2006. The main strategy behind this reduction has been the improvement of vaccination coverage and implementation of a second opportunity for immunization with the live-attenuated measles vaccine. The Measles Initiative, a partnership between the American Red Cross, CDC, UNICEF, WHO and UN Foundation, has had a significant role in this achievement. Here, we provide an overview of old and new vaccination strategies, and discuss changes in the route of administration of the existing live-attenuated vaccine, the development of new-generation nonreplicating measles virus vaccine candidates and attempts to use recombinant measles virus as a vector for vaccination against other pathogens.

Genetic studies of African populations: an overview on disease susceptibility and response to vaccines and therapeutics

Africa is the ultimate source of modern humans and as such harbors more genetic variation than any other continent. For this reason, studies of the patterns of genetic variation in African populations are crucial to understanding how genes affect phenotypic variation, including disease predisposition. In addition, the patterns of extant genetic variation in Africa are important for understanding how genetic variation affects infectious diseases that are a major problem in Africa, such as malaria, tuberculosis, schistosomiasis, and HIV/AIDS. Therefore, elucidating the role that genetic susceptibility to infectious diseases plays is critical to improving the health of people in Africa. It is also of note that recent and ongoing social and cultural changes in sub-Saharan Africa have increased the prevalence of non-communicable diseases that will also require genetic analyses to improve disease prevention and treatment. In this review we give special attention to many of the past and ongoing studies, emphasizing those in Sub-Saharan Africans that address the role of genetic variation in human disease.

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.

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?).

Effects of chronic stress and interleukin-10 gene polymorphisms on antibody response to tetanus vaccine in family caregivers of patients with Alzheimer's disease

OBJECTIVE

To assess the effects of psychological stress on the antibody response to tetanus vaccine adjusting for cytokine gene polymorphisms and other nongenetic factors in caregivers of patients with Alzheimer's disease (AD).

METHODS

A family-based follow-up study was conducted in 119 spouses and offspring of community-dwelling patients with AD. Psychological stress was measured by the Perceived Stress Scale (PSS) and the Center for Epidemiologic Studies Depression (CES-D) scale at baseline and 1 month after the vaccination. Nutritional status, health behaviors, comorbidity, and stress-buffering factors were assessed by self-administered questionnaires, 10 single nucleotide polymorphisms (SNP) from six selected cytokines genotyped, and anti-tetanus toxoid immunoglobulin G (IgG) concentrations tested using enzyme-linked immunosorbent assays. The effects of stress and other potential confounders were assessed by mixed models that account for familial correlations.

RESULTS

The baseline PSS score, the baseline CES-D score, the interleukin-10-1082 A>G SNP GG genotype, and the baseline anti-tetanus IgG were inversely associated with antibody fold increase.

CONCLUSION

Both psychological stress and cytokine gene polymorphisms affected antibody fold increase. The study provided additional support for the detrimental effects of psychological stress on the antibody response to tetanus vaccine.

HLA homozygosity does not adversely affect measles vaccine-induced cytokine responses

The association between HLA homozygosity and measles-specific Th(1) (IFN-gamma, IL-2 and IL-12p40) and Th(2) (IL-4 and IL-10) cytokine responses were assessed in a group of 339 healthy schoolchildren 12-18 years of age previously immunized with two doses of live-attenuated measles virus vaccine. No associations were observed between class I HLA homozygosity and measles-specific cytokine levels. Children who were homozygous at the class II DRB1, DQA1, DPA1 and DPB1 loci had higher median IFN-gamma secretion levels compared with children who were heterozygous for DRB1 (77.7 vs. 39.5 pg/ml, p=0.05), DQA1 (60.9 vs. 36.6 pg/ml, p=0.03), DPA1 (46.1 vs. 27.1 pg/ml, p=0.01) and DPB1 (61.5 vs. 36.0 pg/ml, p=0.01) loci, respectively. Homozygosity at increasing numbers of HLA loci ( >or=4) was associated with increased IFN-gamma secretion levels (test for trend p-value=0.01). Our results suggest that HLA homozygosity showed no disadvantage for measles-specific cytokine responses and instead was associated with increased IFN-gamma levels.

Human leukocyte antigen polymorphisms: variable humoral immune responses to viral vaccines

Antibody formation in response to antigen stimulation remains the basis for measuring an individual's response and protection for most viral vaccines. A significant proportion of the variation in individual humoral immune response to vaccination appears to be genetic. The collection of genes found on chromosome 6 forming the human leukocyte antigen system provides one of the greatest sources of genetic variation in individuals with respect to their immunological responses. Recent research has demonstrated significant associations between vaccine response and human leukocyte antigen alleles. These associations not only explain why vaccine-induced humoral immune responses vary among individuals and between populations, but these variations may also hold the key to the development of future generations of vaccines.

Measles

PURPOSE OF REVIEW

The purpose of this review is to summarize important papers concerning measles disease and measles-containing vaccines published in 2004.

RECENT FINDINGS

Endemic measles has been successfully controlled in the Americas and, to a lesser extent, in Europe. This has been achieved with a high uptake of two doses of a measles-containing vaccine. Even in industrialized countries, where vaccine uptake is poor, for example Japan, the disease is still a significant cause of morbidity and mortality. Vaccine failure is predominantly due to primary vaccine failure, which may, in part, be genetic in origin and related to HLA type. Measles-containing vaccines have been shown to be associated with febrile convulsions, but there is no strong evidence of a link with atopy. There is considerable evidence that there is no causal relationship with autistic disorders. In spite of this, many parents and some professionals have concerns about the safety of the vaccines, which may lead to their underuse.

SUMMARY

It is possible to eliminate measles with a high uptake of two doses of measles-containing vaccine, but concerns about safety persist and need to be tackled. More research is required into how to do this effectively and also to elucidate the causes of vaccine failure.

HLA class II alleles and measles virus-specific cytokine immune response following two doses of measles vaccine

Measles virus-specific T cells and the production of cytokines play a critical role in the immune response following measles immunization. To understand the genetic factors that influence variation in IFN-gamma and IL-4 responses following measles immunization and to provide insight into the factors influencing both cellular and humoral immunity to measles, we assessed associations between human leukocyte antigen (HLA) class II genes and measles-specific Th1 and Th2-type cytokine responses in peripheral blood lymphocytes from 339 children previously vaccinated with two doses of measles-mumps-rubella vaccine (MMR-II). Median values for measles-specific IFN-gamma and IL-4 secretion levels were 40.73 and 9.71 pg/ml, respectively. The global tests suggested associations between measles-specific IFN-gamma response and alleles of the DRB1 and DQB1 loci (P=0.07 and P=0.02, respectively). Specifically, DRB1*0301, *0901, and *1501 alleles were significantly associated with IFN-gamma secretion. The alleles that suggested evidence of an HLA association with IL-4 secretion were DRB1*0103, *0701, and *1101. Th1 cytokine responses and DQB1 allele associations revealed that the alleles with the strongest association with IFN-gamma secretion were DQB1*0201, *0303, *0402, and *0602. Specific alleles with a suggestive association with low measles-specific Th2 cytokine responses were DQB1*0202 and *0503. In addition, DPB1*0101, *0201, and *0601 alleles provided suggestive evidence of an HLA association with measles-induced IFN-gamma response, while DPB1*0501 was associated with an IL-4 response. These data suggest that IFN-gamma and IL-4 cytokine responses to measles may be genetically restricted in part by HLA class II genes, which in turn can restrict the cellular immune response to measles vaccine.

Variation in vaccine response in normal populations

Genetic polymorphisms of the human leukocyte antigen (HLA) system significantly influence the variation in immune responses to viral vaccines. Considerable data on the genetic determinants of immune responses to the measles vaccine support the importance of HLA genes in determining the variation in vaccine response. HLA class I and class II, TAP, and HLA-DM allele associations with measles-specific antibody levels following measles vaccination have revealed, in part, the immunologic basis for mechanisms of measles immunity variation. Associations between HLA genotype and immune responses have also been reported for other vaccines and infectious diseases, such as hepatitis B and C, human papillomaviruses, and influenza. Vaccine pharmacogenomics may provide important insights for the design and development of new peptide-based vaccines against measles and other pathogens.