Genetic prediction of nonresponse to hepatitis B vaccine

Kinetics of COVID-19 mRNA primary and booster vaccine-associated neutralizing activity against SARS-CoV-2 variants of concern in long-term care facility residents: a prospective longitudinal study in Japan

BACKGROUND

Coronavirus disease 2019 (COVID-19) remains a threat to vulnerable populations such as long-term care facility (LTCF) residents, who are often older, severely frail, and have multiple comorbidities. Although associations have been investigated between COVID-19 mRNA vaccine immunogenicity, durability, and response to booster vaccination and chronological age, data on the association of clinical factors such as performance status, nutritional status, and underlying comorbidities other than chronological age are limited. Here, we evaluated the anti-spike IgG level and neutralizing activity against the wild-type virus and Delta and Omicron variants in the sera of LTCF residents, outpatients, and healthcare workers before the primary vaccination; at 8, 12, and 24 weeks after the primary vaccination; and approximately 3 months after the booster vaccination. This 48-week prospective longitudinal study was registered in the UMIN Clinical Trials Registry (Trial ID: UMIN000043558).

RESULTS

Of 114 infection-naïve participants (64 LTCF residents, 29 outpatients, and 21 healthcare workers), LTCF residents had substantially lower anti-spike IgG levels and neutralizing activity against the wild-type virus and Delta variant than outpatients and healthcare workers over 24 weeks after the primary vaccination. In LTCF residents, booster vaccination elicited neutralizing activity against the wild-type virus and Delta variant comparable to that in outpatients, whereas neutralizing activity against the Omicron variant was comparable to that in outpatients and healthcare workers. Multiple regression analyses showed that age was negatively correlated with anti-spike IgG levels and neutralizing activity against the wild-type virus and Delta variant after the primary vaccination. However, multivariate regression analysis revealed that poor performance status and hypoalbuminemia were more strongly associated with a lower humoral immune response than age, number of comorbidities, or sex after primary vaccination. Booster vaccination counteracted the negative effects of poor performance status and hypoalbuminemia on the humoral immune response.

CONCLUSIONS

LTCF residents exhibited suboptimal immune responses following primary vaccination. Although older age is significantly associated with a lower humoral immune response, poor performance status and hypoalbuminemia are more strongly associated with a lower humoral immune response after primary vaccination. Thus, booster vaccination is beneficial for older adults, especially those with a poor performance status and hypoalbuminemia.

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.

Susceptibility to hepatitis B virus infection in adults living in Spain

BACKGROUND

A protective hepatitis B virus (HBV) vaccine has been available for four decades. Universal HBV vaccination of infants is recommended by the WHO since the 1990s. Furthermore, HBV immunization is advised for all adults with high-risk behaviours and no seroprotection. However, HBV vaccine coverage remains globally suboptimal. The advent of new more efficacious trivalent HBV vaccines has renewed the interest in HBV vaccination. At present, the extent of current HBV susceptibility in adults remains unknown in Spain.

METHODS

HBV serological markers were assessed on a large and representative sample of adults in Spain, including blood donors and individuals belonging to high-risk groups. Serum HBsAg, anti-HBc and anti-HBs were tested in specimens collected during the last couple of years.

RESULTS

From 13 859 consecutive adults tested at seven cities across the Spanish geography, overall 166 (1.2%) had positive HBsAg. Past HBV infection was recognized in 14% and prior vaccine immunization in 24%. Unexpectedly, 37% of blood donors and 63% of persons belonging to high-risk groups had no serum HBV markers and therefore were potentially HBV susceptible.

CONCLUSION

Roughly 60% of adults living in Spain seem to be HBV susceptible. Waning immunity might be more common than expected. Hence, HBV serological testing should be performed at least once in all adults regardless of risk exposures. HBV vaccine full courses or boosters should be administered to all adults lacking serological evidence of HBV protection.

Associations of HLA Polymorphisms with Anti-SARS-CoV-2 Spike and Neutralizing Antibody Titers in Japanese Rheumatoid Arthritis Patients Vaccinated with BNT162b2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019. Anti-SARS-CoV-2 spike (S) and neutralizing antibodies (Abs) are measured to evaluate the efficacy of vaccines. Human leukocyte antigen (HLA) may be associated with vaccine efficacy. Here, we investigated the association of HLA polymorphisms with the production of anti-SARS-CoV-2 S or neutralizing Abs in vaccinated rheumatoid arthritis (RA) patients in Japan. Genotyping of DRB1 and DQB1 was conducted in 87 Japanese RA patients vaccinated with BNT162b2. Associations of allele or haplotype carrier frequencies with anti-SARS-CoV-2 S or neutralizing Abs were examined. DRB1*12:01 was significantly positively associated with the production of S Ab (p = 0.0225, odds ratio [OR] 6.08, 95% confidence interval [CI] 1.32-28.03). The DQB1*03:01 allele carrier frequency tended to be higher in high responders of S Ab. Allele carrier frequencies of DRB1*15:01 (p = 0.0102, OR 9.26, 95% CI 1.65-52.01) and DQB1*06:02 (p = 0.0373, OR 7.00, 95% CI 1.18-41.36) were higher in responders of neutralizing Ab. Haplotype and two-locus analyses of DRB1 and DQB1 suggested that DRB1 alleles were the primary drivers of these associations. Logistic regression analysis showed associations of these alleles independent of clinical characteristics. Independent associations were found between HLA alleles and anti-SARS-CoV-2 Ab production by vaccinated RA patients.

Hepatitis A and hepatitis B infection risk among employees at schools for disabled pupils

Aim of this project was to assess occupational biological hazards with regard to the risk of hepatitis A (HAV) and hepatitis B (HBV) and the need for occupational health care in schools for pupils with special needs. Teachers and educational specialists were surveyed about activities potentially providing exposure to biological agents and their individual immune status regarding HAV and HBV by a detailed questionnaire. Descriptive analyses, group comparisons and logistic regression were performed to identify factors influencing the HAV and HBV immune status. 1398 teachers and educational specialists took part. 1381 respondents reported having physical contact with pupils at work (98%). Daily contact was reported by up to 84% of all employees. Being scratched, bitten or spat at was reported by up to 93%. Hazardous activities are performed by both teachers and educational specialists. The vaccination rate was reported to be 58% for HAV and 64% for HBV. In regression analyses, failing to receive vaccine counselling [HAV: aOR 0.36 (95% CI 0.28; 0.46; p < 0.001), HBV: aOR 0.43 (95% CI 0.33; 0.55; p < 0.001)] or non-participation in infection prevention instruction [HBV: aOR 0.54 (95% CI 0.39; 0.75; p < 0.001)] were found to be significant predictors of low vaccination rates. Employees who are at risk due to occupational exposure should be instructed about infection prevention and vaccination against HAV and HBV.

Antibody response to an accelerated course of Hepatitis B vaccination

BACKGROUND

There are several courses with different dosing intervals for Hepatitis B vaccination. This independent study is looking at the antibody response after three doses of the accelerated course.

AIMS

The primary aim of the study was to examine data available at an Occupational Health Service for the antibody response to one or if nonresponsive, two accelerated Hepatitis B courses. A secondary aim is to determine if there is a difference in response for different sex and age groups.

METHODS

This is a retrospective anonymous and blinded study looking at the antibody response in 1032 healthcare personnel given the accelerated course of the Hepatitis B vaccine over a period of over 6 years. An anti-Hbs response 4 months after the start of the vaccination of >10 IU/ml was taken as indicative of a response.

RESULTS

After one course, 93% of the healthcare personnel developed antibody levels thought to confer immunity. After two courses, nearly 99% of the healthcare personnel had developed an adequate immune response. The response was better in females and <40 years old, a difference that was statistically significant for those aged <40.

CONCLUSIONS

The accelerated course confers high levels of immunity after 4 months and this supports the current practice of offering the accelerated dose to UK healthcare personnel who can be at immediate and higher risk of infection. Though some groups are less responsive, all groups mount a good response so all those at risk should be encouraged to have this vaccination.

Protective HLA alleles against severe COVID-19: HLA-A*68 as an ancestral protection allele in Tapachula-Chiapas, Mexico

HLA is a polymorphic antigen presenter which has provided valuable information on the susceptibility of populations to viruses. Therefore, the study of HLA can reveal specific susceptibility or resistance alleles to severe COVID-19 in an ethnically dependent manner. This pilot study investigated HLA alleles associated with COVID-19 severity in Tapachula, Chiapas, Mexico. A total of 146 Mexican Mestizos were typed for HLA class I and II using PCR-SSP. The patients were classified according to the outcome (death or improvement) and the infection's severity (mild or severe). In addition, a group of exposed uninfected individuals was included. HLA-A*68 was found to be a protective allele against the severe infection and fatal outcome; pC = 0.03, OR = 0.4, 95% CI =0.20-0.86, and pC =0.009, OR = 0.3, 95% CI =0.13-0.71 respectively. HLA-DRB1*03 also appears to be a protective factor against fatal outcome pC = 0.009, OR = 0.1, 95%IC = 0.01-0.66; however, the low frequency of this allele in the studied population limits the statistical power. The severity and fatal outcome of COVID-19 patients in Tapachula, Chiapas depend more on the lack of resistance than susceptibility HLA alleles.

How Do We Predict a Patient's Disease Course and Whether They Will Respond to Specific Treatments?

Gastroenterologists will be all too familiar with the difficult decisions that managing inflammatory bowel disease often presents. How aggressively should I treat this patient? Do I expect them to have a mild or aggressive form of disease? Do they need a biologic? If so, which one? And when should I start it? The reality is that the answers that would be right for one patient might be disastrous for another. The growing therapeutic armamentarium will only make these decisions more difficult, and yet, we have seen how other specialties have begun to use the molecular heterogeneity in their diseases to provide some answers. Here, we review the progress that has been made in predicting the future for any given patient with inflammatory bowel disease-whether that is the course of disease that they will experience or whether or not they will respond to, or indeed tolerate, a particular therapy.

Immunogenicity and safety of hepatitis B vaccination in patients with type 2 diabetes in China: An open-label randomized controlled trial

OBJECTIVE

Hepatitis B virus (HBV) infection remains a global public health challenge. Patients with diabetes are at greater risk of HBV infection than healthy people. The immunogenicity and safety of two major hepatitis B vaccines were evaluated in Chinese patients with diabetes.

METHODS

In this phase IV, open-label, randomized, controlled study, participants with diabetes were randomly recruited from 6 townshiphealthcenters in Gansu Province and received either a 3-dose Saccharomyces cerevisiae recombinant hepatitis B vaccine (Group D20SC 0-1-6, n = 113) or a 3-dose Chinese hamster ovary cell (CHO) recombinant hepatitis B vaccine (Group D20CHO 0-1-6, n = 119). Healthy control groups were randomly recruited from the same 6 health centers and received 3 doses of the saccharomyces cerevisiae recombinant hepatitis B vaccine (Group ND20SC 0-1-6, n = 77). Immunogenicity, including seroconversion rate and geometric mean concentration (GMC) at 1 month after three doses of vaccination, and safety were assessed. The seroconversion rate was defined as the concentration of HBsAb ≥ 10 mIU/mL.

RESULTS

The seroconversion rates of Group D20SC 0-1-6, Group D20CHO 0-1-6 and Group ND20SC 0-1-6 were 89.6%, 91.4% and 97.1%, respectively, in the per-protocol analysis, and these differences were not statistically significant. The antibody concentration in Group D20SC 0-1-6 (GMC = 601 mIU/mL) was lower than that of the healthy control group (GMC = 1465 mIU/mL), but no significant difference was found in the GMC between the Group D20CHO 0-1-6 (GMC = 778 mIU/mL) and Group D20SC 0-1-6. Adverse events (AEs) were comparable between groups, and no serious AEs were found in these three groups.

CONCLUSIONS

The Saccharomyces cerevisiae recombinant and CHO recombinant hepatitis B vaccines in China can induce good immunogenicity in a diabetic population, although the antibody concentration may be lower, indicating the feasibility of vaccinating a large number of diabetic patients in China with these vaccines.

Structural Analysis of the Polymerase Protein for Multiepitopes Vaccine Prediction against Hepatitis B Virus

Hepatitis B virus (HBV) is the most common cause of hepatocellular carcinoma and liver cirrhosis with significant morbidity and mortality worldwide. DNA polymerase protein of HBV is the immunogenic protein inducing immune response against B and T cells. The aim of this study wasto develop multi-epitope vaccine fromthe polymerase protein elicitingimmune responses.The predicted vaccine comprises epitopes against B and T lymphocytesobtained by IEDB server. The predicted epitopes were linked via suitable spacers (linkers). The 50S ribosomal protein L7/L12 was used as an adjuvant at amino terminal and His-tag at the carboxyl terminal of the vaccine construct. The candidate vaccine contains 457aa and was potentially antigenic and nonallergic. Vaccine molecular weightwas 50.03 KDa with pI of 10.04. The instability index was 25.78 and GRAVY was -0.354 indicating stability andhydrophilicity of the chimeric vaccine,respectively.Vaccine structure (Secondary and tertiary structures) were predicted, refined and used for molecular docking with TLR4.The docking with TLR4 provided energy scores of -1458.7 and -1410.3 for chain A and B, respectively, demonstrated strong binding between the chimeric vaccine and TLR4 chains.The vaccine provided favorable solubility compared to E. coli proteins. Stability via disulfide bonds engineering was predicted to reduce the entropy and mobility regions invaccine construct. Molecular dynamics simulation wasperformed to strengthen the prediction. In silicomolecular cloning was usedto guarantee the efficient clonabilityof the vaccine and translation within suitable vector.

Clinical Characteristics of Children With Celiac Disease Not Responding to Hepatitis B Vaccination in India

The immunological response to hepatitis B virus (HBV) vaccine may be suboptimal in children with celiac disease (CD), but the reasons for this are not well defined.

Objectives

This study was undertaken to assess the immune response to HBV vaccine in CD children and to explore the possible factors affecting the immune response.

Methods

The study population consisted of 3 groups-50 newly diagnosed CD children (group 1), 50 previously diagnosed CD children who were on gluten free diet (GFD) >3 months (group 2), and 100 age and gender matched healthy controls (group 3). The patient characteristics were recorded, and the blood samples were analyzed for HBsAg and anti-HBs titers. The nonresponders were given a booster dose of HBV vaccine and reevaluated after 6 weeks.

Results

Positive anti-HBs response was found in 46% in newly diagnosed CD children, 60% in CD children on GFD, and 83% in healthy controls (P < 0.001). The immune response to HBV vaccine in CD children was inferior to that in healthy children (53% vs 83%, P < 0.001). The immune response was found to be significantly affected by age at diagnosis, delay in diagnosis, type of presentation, and compliance to GFD. 44 out of 45 (97.77%) nonresponders from CD group seroconverted after a single booster dose.

Conclusion

Early diagnosis and good compliance to GFD may improve the immune response to HBV vaccine in CD children. Single additional booster dose is sufficient to attain optimal immune response.

Onchocerca volvulus bivalent subunit vaccine induces protective immunity in genetically diverse collaborative cross recombinant inbred intercross mice

This study tests the hypothesis that an Onchocerca volvulus vaccine, consisting of two recombinant antigens (Ov-103 and Ov-RAL-2) formulated with the combination-adjuvant Advax-2, can induce protective immunity in genetically diverse Collaborative Cross recombinant inbred intercross mice (CC-RIX). CC-RIX lines were immunized with the O. volvulus vaccine and challenged with third-stage larvae. Equal and significant reductions in parasite survival were observed in 7 of 8 CC-RIX lines. Innate protective immunity was seen in the single CC-RIX line that did not demonstrate protective adaptive immunity. Analysis of a wide array of immune factors showed that each line of mice have a unique set of immune responses to vaccination and challenge suggesting that the vaccine is polyfunctional, inducing different equally-protective sets of immune responses based on the genetic background of the immunized host. Vaccine efficacy in genetically diverse mice suggests that it will also be effective in genetically complex human populations.

Need to take special care of non-responders to hepatitis B vaccination among health-care workers, students and chronic patients

Both our research and that published by Sticchi et al. on immunological memory against hepatitis B virus (HBV) in health-care workers (HCWs) vaccinated as infants or adolescents confirm that in those testing negative after the primary course, one additional (fourth) booster dose is able to elicit an anti-HBs response in >85% subjects. The fifth and the sixth doses further contribute substantially to a high overall response rate. The rate of subjects showing an anamnestic response after the booster dose was almost six-fold higher in HCWs compared to chronic patients. Since universal vaccination in Italy resulted in a significant decrease in HBV infections, special attention and testing should be addressed to those affected by chronic diseases.

Vaccinomics and Adversomics in the Era of Precision Medicine: A Review Based on HBV, MMR, HPV, and COVID-19 Vaccines

Precision medicine approaches based on pharmacogenomics are now being successfully implemented to enable physicians to predict more efficient treatments and prevention strategies for a given disease based on the genetic background of the patient. This approach has already been proposed for vaccines, but research is lagging behind the needs of society, and precision medicine is far from being implemented here. While vaccinomics concerns the effectiveness of vaccines, adversomics concerns their side effects. This area has great potential to address public concerns about vaccine safety and to promote increased public confidence, higher vaccination rates, and fewer serious adverse events in genetically predisposed individuals. The aim here is to explore the contemporary scientific literature related to the vaccinomic and adversomic aspects of the three most-controversial vaccines: those against hepatitis B, against measles, mumps, and rubella, and against human Papilloma virus. We provide detailed information on the genes that encode human leukocyte antigen, cytokines and their receptors, and transcription factors and regulators associated with the efficacy and safety of the Hepatitis B and Measles, Mumps and Rubella virus vaccines. We also investigate the future prospects of vaccinomics and adversomics of a COVID-19 vaccine, which might represent the fastest development of a vaccine ever.

Common Genetic Variations Associated with the Persistence of Immunity following Childhood Immunization

Vaccines have revolutionized public health, preventing millions of deaths each year, particularly in childhood. Yet, there is considerable variability in the magnitude and persistence of vaccine-induced immunity. Maintenance of specific antibody is essential for continuity of vaccine-induced serological protection. We conducted a genome-wide association study into the persistence of immunity to three childhood vaccines: capsular group C meningococcal (MenC), Haemophilus influenzae type b, and tetanus toxoid (TT) vaccines. We detail associations between variants in a locus containing a family of signal-regulatory proteins and the persistence MenC immunity. We postulate a regulatory role for the lead SNP, with supporting epigenetic and expression quantitative trait loci data. Furthermore, we define associations between SNPs in the human leukocyte antigen (HLA) locus and the persistence of TT-specific immunity. Moreover, we describe four classical HLA alleles, HLA DRB1^∗0301, HLA DQB1^∗0201, HLA DQB1^∗0602, and HLA DRB1^∗1501, associated with TT-specific immunity, independent of the lead SNP association.

Vaccinations and Immune Response in Celiac Disease

Immune response to vaccinations in celiac patients is of growing scientific interest. However, some aspects of the relationship between celiac disease (CD) and vaccines are still unclear. A comprehensive search of published literature using the PubMed database was carried out using the following key terms: "adaptive immunity", "celiac disease", "humoral immune response", "immunization", and "vaccination". To date, there is no evidence showing any causative association between vaccines and CD development. Therefore, vaccinations may be administered according to the modalities and timing of the National Immunization Schedule for each country. The rotavirus vaccine is currently recommended for the general population, and according to some data, it appears to reduce the risk for the development of CD autoimmunity in the early years of life. Regarding the hepatitis B virus, a booster dose of the vaccine is often required due to the low or the lost immune response rate in CD. Furthermore, determination of hepatitis B antibody titers could be useful in newly diagnosed CD subjects regardless of age at diagnosis. Finally, pneumococcal vaccines may be administered in patients with advancing age at diagnosis and concomitant risk factors. Future clinical practice guidelines for vaccination and monitoring programs in celiac patients could be recommended.

Personalized Human Papillomavirus Vaccination for Persistence of Immunity for Cervical Cancer Prevention: A Critical Review With Experts' Opinions

The development of cervical cancer has been shown to involve both viral and host factors. The host factors are those that determine the specific response to human papillomavirus (HPV) infection by the patient's immune system. The immune responses to vaccines have been shown to be influenced by polymorphisms in genes involved in innate and adaptive immunity. The specific genetic variants that may influence the immune responses to HPV vaccine which may contribute to persistence of immunity (POI) have not been widely studied yet. In order to address the question as to “is it right to vaccinate all children, and all with equal dose?” we have critically examined the knowledge of common immunogenetic and immunogenomic variations that may influence the HPV vaccine POI across various populations. We have also identified a number of specific research questions that need to be addressed in future research into host molecular genetic variations and HPV vaccine POI in order to afford life-long protection against the development of cervical cancer. This work informs future insights for improved HPV vaccine designs based on common host molecular genetic variations.

Evaluation of the immune memory response to routine HBV vaccine in Egyptian patients with Type 1 diabetes

We aimed to evaluate the immune memory response to HBV vaccine in diabetic patients who had received the full HBV vaccination during infancy and to assess the need for booster doses. Blood samples were collected from children (93 diabetics and 105 controls) and university students (22 diabetics and 20 controls). Anti-HBs titer in serum and after in vitro stimulation of peripheral blood mononuclear cells with HBV vaccine was measured by ELISA. Diabetic groups had significantly lower anti-HBs levels after 10 years of the last HBV vaccine dose. The percentage of diabetic patients having protective anti-HBs titers was significantly lower than controls. In conclusion, diabetic patients had lower immune response to HBV vaccine over time, emphasizing the need for a booster dose.

Low Seroconversion with Hepatitis B Vaccination in Peritoneal Dialysis Patients

Objective

To compare seroconversion using hepatitis B vaccine between hemodialysis (HD) and peritoneal dialysis (PD) patients.

Design

Data on PD patients vaccinated were collected retrospectively for the period 1992 to 1995. The data on HD patients were collected prospectively from 1991 to 1994.

Setting

A university outpatient dialysis center.

Participants

All adult patients who received all four doses of hepatitis B vaccine while on dialysis were included (47 PD and 50 HD patients).

Intervention

Recombinant hepatitis B vaccine (Engerix), 40 μg IM was administered at 0, 1, 2, and 6 months.

Main Outcome Measure

Seroconversion was measured after completion of the vaccination series.

Results

74% of the HD patients seroconverted compared to 53 % of PD patients (p = 0.03). Older, heavier patients compared to all the other patients had a lower seroconversion rate in both the HD patients (55 % vs. 78 %) and PD patients (38 % vs. 59 %) (p = 0.03).

Conclusion

The seroconversion rate to recombinant hepatitis B vaccine is lower in patients on PD than on HD for unclear reasons. Further studies are required to determine the etiology of this difference.

Evaluation of antibody persistence after a four-dose primary hepatitis B vaccination and anamnestic immune response in children under 6 years

Introduction. Tunisia is an intermediate hepatitis B virus (HBV) endemic country. The vaccination against hepatitis B was introduced in 1995 including four doses with a first dose administrated at birth. Decreasing the level of antibodies against hepatitis B surface antigen (anti-HBs) over time can be alarming. This study was conducted to explore the anti-HBV immune response among children under 6 years old, vaccinated according to the national vaccination schedule, by evaluating the immunological response to primary vaccination and by exploring the anamnestic immune response to a booster dose.Methods. We conducted a cross-sectional prospective study from June 2016 to June 2017 (n=180), based on voluntary participation. Children were recruited from the public pediatric ward sectors in Sahloul University Hospital of Sousse in Central Tunisia. An anti-HB titre was determined based on electro-chemiluminescence micro-particle immunoassay (ECLIA), using Elecsys Anti-HBs II kit, Roche.Results. Mean age at the time of enrollment in the study was 33±14.8 months. The seroprotection rate was 77.2 %. The anti-HB titre differed significantly between the different age groups (P=0.002). The predicting variable for having no seroprotective antibody level was older age. Children with anti-HB levels <10 IU l^{- 1} were offered an additional dose of HBV vaccine. Anamnestic response 1 month after the challenge dose was observed in 100 % of subjects. The probability of developing a high antibody response, following the booster dose increased in conjunction with an increased pre-booster antibody level.Conclusion. The response to a booster dose suggests the persistence of immune memory in almost all vaccinated individuals. Although a booster dose increases substantially anti-HB titre, the clinical relevance of such an increase remains unknown.

A Global View to HBV Chronic Infection: Evolving Strategies for Diagnosis, Treatment and Prevention in Immunocompetent Individuals

Hepatitis B Virus (HBV) is a significant public health challenge. Around 250 million people live with chronic HBV infection. With a global approach to this issue, we focus on new perspective in diagnosis, management and prevention of HBV chronic infection. Precise diagnosis of HBV status is crucial to guide patient management. Although available drugs reduce the risk of liver disease progression, they are not able to definitely eradicate HBV, and new therapeutic options are urgently needed. Thus, prevention of HBV infection is still the most effective strategy to achieve the control of the disease. Key aspects of prevention programs include surveillance of viral hepatitis, screening programs and immunization strategies. In spite of the high success rate of licensed HBV vaccines, a need for improved vaccine persists, especially in order to provide coverage of current non-responders.

Variables linked to hepatitis B vaccination success in non-dialyzed chronic kidney disease patients: Use of a bayesian model

BACKGROUND

Hepatitis B vaccination is recommended for chronic kidney disease (CKD) patients before starting dialysis. We performed an analyis aimed to describe the clinical and biological parameters related to the success of vaccination in CKD patients before starting dialysis.

METHODS

We extracted data of 170 non-dialyzed patients who were offered hepatitis B vaccination from a register. They received a first vaccination of 40μg followed by boosters after one, two and six months. Patients were considered protected if their hepatitis B antibody level was >10IU/L, three months apart. A logistic regression and a Bayesian model were used to describe the relationships between variables and the success of vaccination.

RESULTS

Vaccination protected 50.6% of the patients. Model adjustment to the data was higher using the Bayesian model compared to the logistic regression (with area under the ROC curve of 0.955±0.007 vs 0.775±0.066 respectively). The Bayesian model's robustness studied using a 10 fold cross validation showed a percentage of misclassified subjects of 12.4±1.8%, a sensitivity of 87.7±0.3%, a specificity of 87.5±0.3%, a positive predictive value of 87.8±0.3% and negative predictive value of 87.4±0.2%. As classified by the Bayesian model, the variables most related to successful vaccination were, in descending order: age, eGFR, protidemia, albuminemia, cause of renal failure, gender, previous vaccination and weight.

CONCLUSION

The Bayesian network confirmed that both kidney function and nutritional status of patients are important factors to explain the success of vaccination against hepatitis B in CKD patients before dialysis. For research purposes, before an external validation, the network can be used online at www.hed.cc/?s=Bhepatitis&n=ReseauhepatiteBsup10.neta.

Epitope Selection for HLA-DQ2 Presentation: Implications for Celiac Disease and Viral Defense

We have reported that the major histocompatibility molecule HLA-DQ2 (DQA1*05:01/DQB1*02:01) (DQ2) is relatively resistant to HLA-DM (DM), a peptide exchange catalyst for MHC class II. In this study, we analyzed the role of DQ2/DM interaction in the generation of DQ2-restricted gliadin epitopes, relevant to celiac disease, or DQ2-restricted viral epitopes, relevant to host defense. We used paired human APC, differing in DM expression (DM^null versus DM^high) or differing by expression of wild-type DQ2, versus a DM-susceptible, DQ2 point mutant DQ2α+53G. The APC pairs were compared for their ability to stimulate human CD4⁺ T cell clones. Despite higher DQ2 levels, DM^high APC attenuated T cell responses compared with DM^null APC after intracellular generation of four tested gliadin epitopes. DM^high APC expressing the DQ2α+53G mutant further suppressed these gliadin-mediated responses. The gliadin epitopes were found to have moderate affinity for DQ2, and even lower affinity for the DQ2 mutant, consistent with DM suppression of their presentation. In contrast, DM^high APC significantly promoted the presentation of DQ2-restricted epitopes derived intracellularly from inactivated HSV type 2, influenza hemagglutinin, and human papillomavirus E7 protein. When extracellular peptide epitopes were used as Ag, the DQ2 surface levels and peptide affinity were the major regulators of T cell responses. The differential effect of DM on stimulation of the two groups of T cell clones implies differences in DQ2 presentation pathways associated with nonpathogen- and pathogen-derived Ags in vivo.

Factors That Influence the Immune Response to Vaccination

There is substantial variation between individuals in the immune response to vaccination. In this review, we provide an overview of the plethora of studies that have investigated factors that influence humoral and cellular vaccine responses in humans. These include intrinsic host factors (such as age, sex, genetics, and comorbidities), perinatal factors (such as gestational age, birth weight, feeding method, and maternal factors), and extrinsic factors (such as preexisting immunity, microbiota, infections, and antibiotics). Further, environmental factors (such as geographic location, season, family size, and toxins), behavioral factors (such as smoking, alcohol consumption, exercise, and sleep), and nutritional factors (such as body mass index, micronutrients, and enteropathy) also influence how individuals respond to vaccines. Moreover, vaccine factors (such as vaccine type, product, adjuvant, and dose) and administration factors (schedule, site, route, time of vaccination, and coadministered vaccines and other drugs) are also important. An understanding of all these factors and their impacts in the design of vaccine studies and decisions on vaccination schedules offers ways to improve vaccine immunogenicity and efficacy.

The role of systems biology approaches in determining molecular signatures for the development of more effective vaccines

INTRODUCTION

Emerging infectious diseases are a major threat to public health, and while vaccines have proven to be one of the most effective preventive measures for infectious diseases, we still do not have safe and effective vaccines against many human pathogens, and emerging diseases continually pose new threats. The purpose of this review is to discuss how the creation of vaccines for these new threats has been hindered by limitations in the current approach to vaccine development. Recent advances in high-throughput technologies have enabled scientists to apply systems biology approaches to collect and integrate increasingly large datasets that capture comprehensive biological changes induced by vaccines, and then decipher the complex immune response to those vaccines.

AREAS COVERED

This review covers advances in these technologies and recent publications that describe systems biology approaches to understanding vaccine immune responses and to understanding the rational design of new vaccine candidates.

EXPERT OPINION

Systems biology approaches to vaccine development provide novel information regarding both the immune response and the underlying mechanisms and can inform vaccine development.

Vaccine uptake and immune responses to HBV infection amongst vaccinated and non-vaccinated healthcare workers, household and sexual contacts to chronically infected HBV individuals in the South West Region of Cameroon

Background

HBV infection affects about 257 million people globally and Sub-Saharan Africa has the highest burden. The disease still constitutes a major public health problem despite the advent of preventive measures like the HBV vaccine. This study was aimed at identifying factors that influence vaccine uptake and the efficacy of administered vaccines among people at high risk of HBV infection.

Methods

This was a cross-sectional study conducted between January 2016 and December 2017. A pretested semi-structured questionnaire was used to capture information on sociodemographic and vaccination status from healthcare workers, household and sexual contacts to HBV infected people. HBV serological panel as well as quantitative anti-HBs ELISA test was done for all participants. Additional information was obtained from the institutions that administered the vaccines.

Results

A total of 265 participants with a mean age of 32.1±8.7 were enrolled. Eighty (30.2%) of them had received at least 1 dose of the HBV vaccine while 185 (69.8%) were unvaccinated. Healthcare workers were the most vaccinated (37%). Ignorance, negligence, fear of injection and the cost of the vaccine all contributed to poor vaccine uptake in the study population. Natural immunity was seen in 9 (3.4%) of the participants. Only 64.9% of the vaccinated participants attained the desirable level of anti-HBs (≥10mIU/ml) 1–2 months after ≥ 3 doses of the vaccine. Age, gender, obesity, alcohol and smoking were not significantly associated with poor immune responses. No standardized protocol was followed by the institutions administering the vaccine.

Conclusion

This study revealed very poor vaccine uptake and poor immune responses to the HBV vaccine in the study population and this should urge the health sector in Cameroon to intensify their sensitization on HBV vaccine, standardize the protocol for storing and administering the vaccine, subsidize the cost of the vaccine especially amongst healthcare workers and encourage anti-HBs post vaccination testing.

Evaluation of Response to Hepatitis B Vaccination in Chronic Hemodialysis Patients

Background:

Hemodialysis (HD) patients are at an increased risk of acquiring hepatitis B virus (HBV) infection. Active HBV immunization in these patients is recommended. A response rate in HD patients is variable but generally lower than healthy individuals.

Objective:

The aim of this study is to assess the response of HD patients to the HBV vaccine and correlate response and long-term immunity to various clinical and biomedical factors.

Patients and Methods:

One hundred and one patients, with a mean age 48.7 ± 18.5 years, received 40 μg of HBV vaccine administered intramuscularly in the deltoid region at 0, 1, 2 and 6 months. The patients' responses to the vaccine were determined by measuring hepatitis B surface antibody (HBsAb) 6 weeks after the last injection and monitored thereafter at 3-month intervals.

Results:

Seventy-one patients (70.3%) mounted a response with HBsAb >10 mIU/ml 6 weeks following the fourth dose of vaccine, and thus were considered considered as adequate responders. Forty-nine (48.5%) patients mounted an excellent response with HBsAb >100 mIU/ml 6 weeks after the fourth dose. Thirty patients (29.7%) were nonresponders. Responders were significantly younger than nonresponders (P = 0.01). Gender, hemoglobin level, serum albumin, ferritin, parathyroid hormone level and hepatitis C virus infection had no effect on the response to the vaccine. Similarly, there was no difference in diabetic state and adequacy of HD between the two groups. Fifty-nine patients (88%) had persistent protective antibodies at 1 year, while eight (12%) lost such protection. Predictors of persistent immunity at 1 year were high HBsAb level at the completion of the vaccination regime and, to a lesser extent, young age.

Conclusion:

A 70% response rate to HBV vaccine was observed in the cohort of this study. Young age predicts a favorable response to HBV vaccine in HD patients. High (>100 mIU/ml) HBsAb levels achieved at vaccine completion predict persistent immunity at 1 year.

Lower Baseline Germinal Center Activity and Preserved Th1 Immunity Are Associated With Hepatitis B Vaccine Response in Treated HIV Infection

BACKGROUND

Why HIV-infected individuals have poor responses to standard dose and schedule hepatitis B virus immunization is not well understood.

METHODS

We compared the serologic and cellular immune profiles of treated HIV-infected individuals with similar durations of infection and preserved CD4 counts (> 350 cells/microliter) by hepatitis B vaccine (HBV) response before and after vaccination.

RESULTS

Similar levels of immune activation and plasma cytokine profile were found between non-responders and responders. The baseline plasma levels of CXCL-13, a surrogate of germinal center reactivity, were significantly lower in HBV responders compared to HBV non-responders and were a predictor of both vaccine response and titer. Furthermore, response to HBV vaccination was associated with a significantly higher frequency of circulating IgG^high memory B cells post vaccination and preserved Th1 antigen-specific T-cell responses.

CONCLUSIONS

Taken together, our data suggest that preserved Th1 responses are associated with hepatitis B vaccine response in treated HIV infection.

Maternal anti-HBVs suppress the immune response of infants to hepatitis B vaccine

It is still controversial whether maternal anti-HBV antibodies (anti-HBVs) affect the infants' immune response to hepatitis B virus (HBV) vaccination. This multicentre study aims to address this question. First, we determined whether the transplacental transfer of maternal anti-HBVs occurs by measuring the titres of 90 anti-HBVs-positive pregnant women and their newborns. The anti-HBVs-positive rates of newborns ranged from 89.7% to 100.0%, depending on the maternal anti-HBVs titres. Secondly, we investigated the effects of maternal anti-HBVs on the immune response of infants to HBV vaccination. A total of 1063 mother-and-infant pairs were enrolled and divided into three groups with maternal anti-HBVs titres of <10 IU/L (negative - 37.9%), 10-499 and ≥500 IU/L. The infants' anti-HBVs-positive rate and titres were negatively correlated with maternal anti-HBVs titres: the anti-HBVs-positive rate of infants were 88.9% (360/405), 84.5% (381/451) and 77.3% (160/207) in mothers with low, intermediate and high antibody titres, respectively, P<.0001. Median titres of anti-HBVs (IU/L) among infants were 169.1, 141.0 and 79.4, respectively, P=.020. One hundred and sixty-two infants were negative for anti-HBVs after the standard vaccination, and 120 of 131 of these infants (91.6%) reached anti-HBVs positivity after the first "booster" dose. The maternal anti-HBVs titres did not significantly affect infant response to this booster. In summary, transplacental transfer of anti-HBVs occurs and high titres of maternal anti-HBVs may suppress the immune response of infants to the standard HBV vaccination. The current schedule of the 0, 1 and 6 month may not be the optimal choice of infants with anti-HBVs-positive mothers.

Evidence-Informed Expert Recommendations for the Management of Celiac Disease in Children

Although the need for effective long-term follow-up for patients with celiac disease (CD) has been recognized by many expert groups, published practice guidelines have not provided a clear approach for the optimal management of these patients. In an attempt to provide a thoughtful and practical approach for managing these patients, a group of experts in pediatric CD performed a critical review of the available literature in 6 categories associated with CD to develop a set of best practices by using evidence-based data and expert opinion. The 6 categories included the following: bone health, hematologic issues, endocrine problems, liver disease, nutritional issues, and testing. Evidence was assessed by using standardized criteria for evaluating the quality of the data, grade of evidence, and strength of conclusions. Over 600 publications were reviewed, and 172 were chosen for inclusion. The thorough review of the results demonstrated that the quality of the data available was often insufficient to provide unequivocal best practices. However, using the available data and the clinical experience of the panel, a practical framework for the management of children with CD was created. These recommendations were developed by our expert panel and do not necessarily reflect the policy of the American Academy of Pediatrics. The potential usefulness of these best practices is underscored by the fact that consensus, measured by the outcome of anonymous voting, was reached by the panel for 24 of the 25 questions. We hope that these best practices may be useful to the pediatric gastroenterology and larger general pediatric communities.

HLA class II genes modulate vaccine-induced antibody responses to affect HIV-1 acquisition

In the RV144 vaccine trial, two antibody responses were found to correlate with HIV-1 acquisition. Because human leukocyte antigen (HLA) class II-restricted CD4(+) T cells are involved in antibody production, we tested whether HLA class II genotypes affected HIV-1-specific antibody levels and HIV-1 acquisition in 760 individuals. Indeed, antibody responses correlated with acquisition only in the presence of single host HLA alleles. Envelope (Env)-specific immunoglobulin A (IgA) antibodies were associated with increased risk of acquisition specifically in individuals with DQB1*06. IgG antibody responses to Env amino acid positions 120 to 204 were higher and were associated with decreased risk of acquisition and increased vaccine efficacy only in the presence of DPB1*13. Screening IgG responses to overlapping peptides spanning Env 120-204 and viral sequence analysis of infected individuals defined differences in vaccine response that were associated with the presence of DPB1*13 and could be responsible for the protection observed. Overall, the underlying genetic findings indicate that HLA class II modulated the quantity, quality, and efficacy of antibody responses in the RV144 trial.

Vaccinology in the third millennium: scientific and social challenges

The epidemiology of deaths due to vaccine-preventable diseases has been significantly and positively altered through the use of vaccines. Despite this, significant challenges remain in vaccine development and use in the third millennium. Both new (Ebola, Chikungunya, Zika, and West Nile) and re-emerging diseases (measles, mumps, and influenza) require the development of new or next-generation vaccines. The global aging of the population, and accumulating numbers of immunocompromised persons, will require new vaccine and adjuvant development to protect large segments of the population. After vaccine development, significant challenges remain globally in the cost and efficient use and acceptance of vaccines by the public. This article raises issues in these two areas and suggests a way forward that will benefit current and future generations.

Oral administration of synthetic selenium nanoparticles induced robust Th1 cytokine pattern after HBs antigen vaccination in mouse model

Hepatitis B virus (HBV) infection is known as a life-threatening liver infection and leads to chronic liver disease if left untreated. Nevertheless, the prevalence of HBV infection has been reduced by an approved vaccination approach using recombinant Hepatitis B surface Antigen (HBsAg) and Alum, known as the HBV vaccine. Alum can be used as an adjuvant to increase HBsAg immunogenicity as a strong Th2 stimulator. There is a vital need to stimulate Th1 immunity by HBsAg vaccination; however, the present vaccine does not induce a prophylactic immune response in some groups. The main aim of the present study was to induce a Th1 cytokine pattern and stimulate an immune response after HBsAg vaccination. Experimental mice were fed selenium nanoparticles (SeNPs) and were later immunized with 5μg of Hepatitis B Vaccine. After a period of 30 days, the experimental animals were given two booster doses of SeNPs during their vaccination course. Group one, i.e., the control vaccine group, was only administered the HBsAg vaccine. The two treated groups, Groups 2 and 3, were daily fed different doses of SeNPs (100μg and 200μg, respectively) via gavage. Group four was considered the control group and was only given phosphate buffered saline (PBS). Lymphocyte proliferation, IFN-γ and IL-4 levels, total antibody and the isotypes of IgG1, IgG2a, IgG2b, and IgM were measured by Enzyme Linked Immunosorbent Assay (ELISA). The administration of SeNPs and the HBs antigen vaccine affected the lymphocyte proliferation; moreover, the total antibody responses also increased the IFN-γ level and induced a Th1 response.

CONCLUSIONS

The present study proposed that the administration of SeNPs with a conventional HBs antigen vaccine induces a better immune response with a Th1 bias.

Serologic control against hepatitis B virus among dental students of the University of Granada, Spain

Background

To evaluate the immunological situation against hepatitis B virus (HBV) of a cohort of dentistry students, to analyze the behavior of the levels of hepatitis B surface antigen (anti-HBs) after the administration of one or three vaccine doses, and to determine the influence of age and sex on the immune response.

Material and Methods

This retrospective cohort study included students attending the School of Dentistry of the institution where the study was performed from 2005 to 2012 who had completed the public health vaccination calendar for HBV at the age of 12-13. Data on age, sex, basal anti-HBs levels, post-vaccination anti-HBs results and final anti-HBs levels were collected. Comparisons of the basal and final levels, as well as associations regarding age and sex, were performed by means of the Student t and Chi-square tests.

Results

Of the 359 students, 97 (27.02%) had basal antibody concentrations <10 mIU/ml, whereas in 262 the levels of anti-HBs were ≥10 mIU/ml (72.98%). Of the 288 participating students who completed the School´s protocol for immunization, 287 (99.65%) attained a level of protection ≥10 mIU/ml. Globally, there were statistically significant differences between the basal antibody levels and those achieved after administration of the vaccine and booster, but no association with age or sex was observed.

Conclusions

About 70% of dental students vaccinated as preadolescents had serologic evidence of protection against HBV. Administering a booster is associated with the presence of an excellent immune memory. There is clearly a need to reinforce control of the antibody levels in groups at risk, such as Dentistry students.

Key words:Dental students, hepatitis B virus, serologic control.

Therapeutic Immunoglobulin Selected for High Antibody Titer to RSV also Contains High Antibody Titers to Other Respiratory Viruses

Specific antibodies against infections most relevant to patients with primary immunodeficiency diseases are not routinely evaluated in commercial polyclonal immunoglobulin preparations. A polyclonal immunoglobulin prepared from plasma of donors having high neutralizing antibody titers to respiratory syncytial virus (RSV) was studied for the presence of antibody titers against seven additional respiratory viruses. While donors were not selected for antibody titers other than against RSV, the immunoglobulin preparation had significantly higher titers to 6 of 7 viruses compared to those present in 10 commercially available therapeutic immunoglobulin products (p ≤ 0.01 to p ≤ 0.001). To consider this as a donor-specific attribute, 20 random donor plasma samples were studied individually and identified a significant correlation between the RSV antibody titer and other respiratory virus titers: donors with high RSV titers were more likely to have higher titers to other respiratory viruses. These findings suggest either some humoral antiviral response bias or more frequent viral exposure of certain individuals.

New approaches in hepatitis B vaccination for celiac disease

Celiac disease (CD) is a gluten-induced immune-mediated disorder that has been associated with a defective response to the hepatitis B virus (HBV) vaccination. This unresponsiveness could lead to a world health problem, because non-responder patients could represent a reservoir of HBV-susceptible people that will persist as healthy carriers, leading to the diffusion of the disease. This article presents a literature review of both intramuscular (IM) and intradermal (ID) routes for boosters in celiac patients. We used PubMed database and generated the odds ratio (OR) of the response on the basis of electronic searches of clinical trials. Although our results confirm the positive response of celiac patients to IM vaccination, the ID route seems to be better than the conventional one, since it could provide a saving in cost and a greater immunogenicity.

Serologic response to hepatitis B vaccination among lung transplantation candidates

BACKGROUND

Optimal hepatitis B (HBV) vaccination strategies for lung transplantation (LT) candidates are not well established.

METHODS

LT candidates with negative anti-HBs and anti-HBc antibody titers at baseline who received standard-dose HBV vaccination (Recombivax-HB 10 mcg/mL or Engerix-B 20 mcg/mL) administered at months 0, 1, and 6 or an accelerated vaccination schedule on days 0, 7 to 14, and 21 to 28 between June 1988 and October 2012 were studied. Patients who were more likely to undergo LT within 6 months of evaluation received the accelerated vaccination schedule starting in August 2009.

RESULTS

Ninety-six HBV-seronegative patients who completed the vaccination series and had postvaccination anti-HBs titers available were identified. Median age was 60 years; 55.2% were female, and 92.7% were white. Underlying lung diseases included COPD (44.8%), idiopathic pulmonary fibrosis (22.9%), interstitial lung disease (15.6%), and cystic fibrosis (8.3%). The overall anti-HBs response rate was 54.2%. There was no significant difference in vaccine responses between accelerated and standard vaccination schedules (54.2% vs. 54.1%; P=1.0). Patients who received steroids or other immunosuppressants before transplantation had lower response rates compared with those who did not (38.9% vs. 63.3%; P=0.03).

CONCLUSIONS

Better vaccination strategies to improve response rate are needed in this population. The accelerated HBV vaccination schedule elicited similar anti-HBs responses as the standard schedule and could be advantageous in this population, given current organ allocation practices, and it could allow repeat vaccination series for initial nonresponders before transplantation.

Enhanced immune response to hepatitis B vaccination through immunization with a Pre-S1/Pre-S2/S vaccine

Efficacy and safety of recombinant yeast-derived hepatitis B vaccines for prevention of hepatitis B have been demonstrated unequivocally worldwide as reflected in reduction in HBsAg carrier rates and hepatocellular carcinoma. A new generation of recombinant HBV vaccines expressed in mammalian cells containing Pre-S/S epitopes has been developed in several countries. Such vaccines are useful in special risk groups, i.e., in non-responders to conventional HBV vaccines including older adults, obese people, health care workers, patients with renal failure and on dialysis, transplant patients, patients with HIV as well as travelers on short notice to HBV endemic regions. The future of such vaccines depends on their enhanced immunogenicity and cost profile. Sci-B-Vac™ is a mammalian cell-derived recombinant Pre-S1/Pre-S2/S hepatitis B vaccine which has been shown to be highly immunogenic, inducing faster and higher seroprotection rates against HBV with higher anti-HBs levels at lower HBsAg doses as compared to conventional yeast-derived vaccines. Recently, it has been suggested that such Pre-S/S vaccines against HBV might be efficacious not only for prevention but also for intervention in persistent HBV infection. Data obtained in a recent clinical trial conducted in Vietnam in patients with chronic hepatitis B suggest that repeated monthly i.m. injections of the Sci-B-Vac™ co-administered with daily oral lamivudine treatment can suppress HBV replication and lead to anti-HBs seroconversion in ~50 % of treated patients. Optimization of protocols and efficacy of such an intervention, intended to bypass T cell exhaustion and immune tolerance to HBV remains to be explored.

Strategy vaccination against Hepatitis B in China

Hepatitis B (HB) is a serious public health problem in China. Up to now, the hepatitis B virus (HBV) vaccination was the most cost-effective way to prevent HBV infection. Since 1992, when the Chinese government prioritized implementing the HBV vaccinations for newborns, China began to see a larger reduction in HBV infections. For children under 5 years, the prevalence of hepatitis B surface antigen (HBsAg) has decreased to 1.0%. However, many additional challenges for the prevention and control of HBV infection in China remain. There is a lack of knowledge of the significant impact of the HBV vaccination for the general public with 93 million HBV carriers and chronic HBV patients as infection sources. Therefore, the HBV vaccine application should focus on the optimization of immunization strategies according to HBV prevalence characteristics, improve the public's knowledge of HBV vaccinations, and help to ensure the protective effects of the HBV vaccine.

Immunogenicity of hepatitis B vaccine in patients with inflammatory bowel disease and the benefits of revaccination

BACKGROUND AND AIM

The vaccination against hepatitis B virus (HBV) is recommended in patients with inflammatory bowel disease (IBD). However, the response to this vaccine seems to be lower in IBD patients than in the general population. This study aims to evaluate the immunogenicity of the HBV vaccine in a cohort of patients with IBD, to associate factors with the response and to analyze the effects of a second schedule vaccination.

METHODS

We conducted a retrospective cohort study of adults with IBD, susceptible to HBV infection. All patients received a three-dose standard schedule of HBV vaccine. Non-responders were revaccinated with a second three-dose standard schedule. Adequate immunity to HBV was defined as antibodies against hepatitis B surface antigen (anti-HBs) ≥ 10 mIU/mL. Age, comorbidities, treatment, and other variables were collected.

RESULTS

One hundred seventy-two patients were included and received the first HBV vaccine schedule. Eighty-seven developed anti-HBs ≥ 10 mIU/mL (50.6%; 95% confidence interval [CI]: 42.9-58.3). From the non-responders, 53 were revaccinated and 28 showed an adequate serological response (52.8%; 95% CI: 38.6-66.7). Age older than 55 years (OR: 3.6; 95% CI: 1.3-10.2) and comorbidities (OR: 2.8; 95% CI: 1.1-7.1) were associated with suboptimal response. In the multivariate analysis, only age was a predictor of non-response (age higher than 55 years; OR: 3.9; 95% CI: 1.3-11.9) CONCLUSION: The response rate to the HBV vaccine is lower in patients with IBD compared with the general population, especially in those older than 55 years. Revaccination improved response rate by 50%.

Normal or defective immune response to Hepatitis B vaccine in patients with diabetes and celiac disease

A defective production of protective levels of antibodies to Hepatitis B (HB) vaccine is reported to occur in 4-10% of healthy subjects and a correlation with the presence of specific human leukocyte antigen (HLA) molecules, including DQ2, which also confers genetic predisposition to celiac disease (CD) and type I diabetes mellitus (T1DM), has been suggested.   The aim of this study was to analyze the serological response to HB vaccine and measles-containing vaccines in 69 diabetic patients (T1DM), 42 patients with celiac disease (CD) and 79 healthy control subjects (CT). The median interval between the third dose of HB vaccine and serum collection was 6.8, 3.5, and 4.7 years for T1DM, CD and CT groups, respectively. 50/69 (72%) T1DM patients, 32/42 (76%) CD patients and 61/79 (77%) CT subjects showed protective anti-HBs antibodies after vaccination, with no statistically significant difference. On the contrary, a lower statistically significant difference was found in the mean HBsAb level of T1DM subjects when compared with the other two groups. No correlation between HLA DQ2 expression in T1DM and vaccine response was detected. The comparison of serological response to measles after vaccination also showed no statistically significant differences in the three groups. Contrasting results between these data and those reported in the literature might be due to differences in the time intervals between vaccination and testing. Prospective studies in pathological and healthy groups with the same age at HBV vaccination and with the same time interval for blood sample collection to determine antibody titers are necessary in order to provide more conclusive data.

Humoral responses to independent vaccinations are correlated in healthy boosted adults

BACKGROUND

Roughly half of U.S. adults do not receive recommended booster vaccinations, but protective antibody levels are rarely measured in adults. Demographic factors, vaccination history, and responses to other vaccinations could help identify at-risk individuals. We sought to characterize rates of seroconversion and determine associations of humoral responses to multiple vaccinations in healthy adults.

METHODS

Humoral responses toward measles, mumps, tetanus toxoid, pertussis, hepatitis B surface antigen, and anthrax protective antigen were measured by ELISA in post-immunization samples from 1465 healthy U.S. military members. We examined the effects of demographic and clinical factors on immunization responses, as well as assessed correlations between vaccination responses.

RESULTS

Subsets of boosted adults did not have seroprotective levels of antibodies toward measles (10.4%), mumps (9.4%), pertussis (4.7%), hepatitis B (8.6%) or protective antigen (14.4%) detected. Half-lives of antibody responses were generally long (>30 years). Measles and mumps antibody levels were correlated (r=0.31, p<0.001), but not associated with select demographic features or vaccination history. Measles and mumps antibody levels also correlated with tetanus antibody response (r=0.11, p<0.001).

CONCLUSIONS

Vaccination responses are predominantly robust and vaccine specific. However, a small but significant portion of the vaccinated adult population may not have quantitative seroprotective antibody to common vaccine-preventable infections.

Analysis of HLA A*02 association with vaccine efficacy in the RV144 HIV-1 vaccine trial

The RV144 HIV-1 vaccine trial demonstrated partial efficacy of 31% against HIV-1 infection. Studies into possible correlates of protection found that antibodies specific to the V1 and V2 (V1/V2) region of envelope correlated inversely with infection risk and that viruses isolated from trial participants contained genetic signatures of vaccine-induced pressure in the V1/V2 region. We explored the hypothesis that the genetic signatures in V1 and V2 could be partly attributed to selection by vaccine-primed T cells. We performed a T-cell-based sieve analysis of breakthrough viruses in the RV144 trial and found evidence of predicted HLA binding escape that was greater in vaccine versus placebo recipients. The predicted escape depended on class I HLA A*02- and A*11-restricted epitopes in the MN strain rgp120 vaccine immunogen. Though we hypothesized that this was indicative of postacquisition selection pressure, we also found that vaccine efficacy (VE) was greater in A*02-positive (A*02(+)) participants than in A*02(-) participants (VE = 54% versus 3%, P = 0.05). Vaccine efficacy against viruses with a lysine residue at site 169, important to antibody binding and implicated in vaccine-induced immune pressure, was also greater in A*02(+) participants (VE = 74% versus 15%, P = 0.02). Additionally, a reanalysis of vaccine-induced immune responses that focused on those that were shown to correlate with infection risk suggested that the humoral responses may have differed in A*02(+) participants. These exploratory and hypothesis-generating analyses indicate there may be an association between a class I HLA allele and vaccine efficacy, highlighting the importance of considering HLA alleles and host immune genetics in HIV vaccine trials.

IMPORTANCE

The RV144 trial was the first to show efficacy against HIV-1 infection. Subsequently, much effort has been directed toward understanding the mechanisms of protection. Here, we conducted a T-cell-based sieve analysis, which compared the genetic sequences of viruses isolated from infected vaccine and placebo recipients. Though we hypothesized that the observed sieve effect indicated postacquisition T-cell selection, we also found that vaccine efficacy was greater for participants who expressed HLA A*02, an allele implicated in the sieve analysis. Though HLA alleles have been associated with disease progression and viral load in HIV-1 infection, these data are the first to suggest the association of a class I HLA allele and vaccine efficacy. While these statistical analyses do not provide mechanistic evidence of protection in RV144, they generate testable hypotheses for the HIV vaccine community and they highlight the importance of assessing the impact of host immune genetics in vaccine-induced immunity and protection. (This study has been registered at ClinicalTrials.gov under registration no. NCT00223080.).

Induction of a robust T- and B-cell immune response in non- and low-responders to conventional vaccination against hepatitis B by using a third generation PreS/S vaccine

Non-responsiveness to conventional hepatitis B vaccines in individuals at high risk of exposure to hepatitis B virus (HBV) is an important public health problem and of particular relevance in health care providers. Yeast-derived conventional HBsAg vaccines fail to induce protective antibody titers in up to 10% of immune competent vaccinees. Therefore, a third generation HBV vaccine, Sci-B-Vac™, was developed which contains in addition to the small S antigen the PreS1 and PreS2 antigens. This vaccine proved to induce a highly potent cellular and humoral immune response in healthy individuals as well as protective antibody levels in non- and low-responders to conventional HBV vaccines. The aim of the study was to examine whether Sci-B-Vac™ triggers cellular and humoral immunity in individuals who failed immunization with conventional vaccines. We immunized 21 volunteers (15 non- and 6 low-responders) according to the standard vaccination schedule (0, 4 and 24 weeks), determined the cellular immunity by proliferation assay and interferon (IFN)-γ ELISpot and measured the anti-HBs antibody titers prior to each vaccination and four weeks after the third vaccine dose. Following three vaccinations, PreS/S-specific T-cell proliferation was detected in 8 out of 15 non-responders and 5 out of 6 low-responders. Specific IFN-γ responses were measured in 2 out of 15 non-responders and 4 out of 6 low-responders. All but one (20/21) study participants developed anti-HBs titers ≥10IU/l after three vaccinations. Anti-HBs ≥100IU/L were detected in 12 out of 15 non-responders and in 6 out of 6 low-responders. Anti-HBs ≥10IU/l and <100IU/l were found in 2 non-responders. These results indicate that Sci-B-Vac™ induces cellular immunity as well as protective anti-HBs antibody titers in non- and low-responders. In conclusion, these results confirm that Sci-B-Vac™ should be administered to non-responders to conventional HBV vaccines and patients with impaired immune function.

Immunisations in Crohn's disease: who? why? what? when?

Immunosuppression induced by drugs increase the risk of infections in Crohn's disease (CD) patients. The vaccination rate in CD patients is usually low due to inaccurate information concerning the safety and efficacy of vaccines. Vaccines and immunoglobulins, are artificial ways of protection from common infectious diseases and they have had a major effect on mortality. Herein we detail the need of protection induced by vaccines of measles, varicella, Zoster, papillomavirus, shingles, pneumococcal invasive disease, influenza, hepatitis A and B in CD at diagnosis and during the course of the disease even during immunosuppression periods but with different singularities. Vaccination in CD travellers and the matters related to immunization of household healthy members of immunosuppressed patients are also discussed.

Background paper to the revised recommendation for hepatitis B vaccination of persons at particular risk and for hepatitis B postexposure prophylaxis in Germany

The German Standing Committee on Vaccination (Ständige Impfkommission, STIKO) recommends vaccinating risk groups against hepatitis B and gives advice for postexposure prophylaxis. STIKO has recently revised this recommendation, focusing on: (i) classification of risk groups, (ii) duration of protection after primary immunization, and (iii) anti-HBs threshold that defines successful hepatitis B vaccination. Orientating literature reviews were performed for the first objective. Examples of population subgroups at increased risk were identified and classified into three indication groups. Systematic reviews on the duration of vaccine-induced protection identified one randomized controlled trial (RCT) and nine cohort studies. When applying the grading of recommendation, assessment, development, and evaluation (GRADE) methodology, evidence from RCTs was considered of very low quality regarding the question of whether hepatitis B can be prevented for 15 years after successful primary vaccination (anti-HBs ≥ 10 IU/l) with a vaccine efficacy of 96 % against chronic hepatitis, 89 % against HBsAg positivity, and 73 % against isolated anti-HBc positivity. However, seven cohort studies showed that no cases of clinical hepatitis B or HBsAg positivity occurred during a maximum follow-up period of 10 years in settings comparable to the situation in Germany when anti-HBs ≥ 10 IU/l was used to indicate vaccination success. Less than 1 % of vaccinated study participants had isolated anti-HBc positivity. GRADE assessment of two cohort studies revealed that evidence of very low quality exists that the use of anti-HBs ≥ 100 IU/l to measure vaccination success leads to a lower frequency of anti-HBc positivity during follow-up than the use of anti-HBs ≥ 10 IU/l. The recommendation was revised according to this evidence.