The effect of age on immunologic response to recombinant hepatitis B vaccine: a meta-analysis

Immune response to hepatitis B vaccine among children under 5 years in Africa: a meta-analysis

BACKGROUND

Hepatitis B virus (HBV) infection in Africa is mostly acquired before the age of 5 years through vertical or horizontal routes. While all the countries in the World Health Organization African region have introduced HBV vaccination into their national immunization programs, the rate of protective immune response to HBV vaccine among children in Africa has not been systematically synthesized. In this study, we estimated the HBV vaccine seroprotection rate (defined as anti-HBs titer ≥ 10 IU/L) and the associated factors among under-five children who completed a primary series of HBV vaccination in Africa.

METHODS

We systematically searched PubMed, Web Science, and Scopus databases from inception to May 2022 for potentially eligible studies. The pooled seroprotection rate was estimated using a random-effects model with Freeman-Tukey double arcsine transformation and the associated factors were examined using odds ratio estimated by the DerSimonian and Laird method.

RESULTS

From the 1063 records identified, 29 studies with a total sample size of 9167 under-five children were included in the meta-analysis. The pooled seroprotection rate was 89.23% (95% CI   85.68-92.33%, I2 = 95.96%, p < 0.001). In the subgroup analyses, there was a significant difference in the rate by the assay method, vaccine dose, and vaccine combination. HIV-positive children had lower odds of achieving seroprotection when compared with HIV-negative children (OR = 0.22, 95%CI   0.12-0.40).

CONCLUSIONS

The majority of under-five children in Africa achieved seroprotection after completing three or four doses of HBV vaccine. However, the rate was lower among children living with HIV. This calls for interventions to timely identify and address nonresponse to HBV vaccine, particularly among immunosuppressed children.

Cytokine IL-5 and HGF: combined prediction of non-/low immune response to hepatitis B vaccination at birth in infants born to HBsAg-positive mothers

Background

The immune response to hepatitis B vaccine may be influenced by numerous factors, and patients with non/low response re-exposed to hepatitis B virus remain susceptible. Thus, a better understanding of the underlying mechanisms of non/low immune response in infants born to Hepatitis B surface antigen (HBsAg)-positive mothers is essential.

Methods

100 infants born to HBsAg-positive mothers from 2015 to 2020 were enrolled in the study, further divided into the non/low response group (n=13) and the moderate strong response group (n=87) based on the quantification of hepatitis B surface antibody at 12 months of age. The differential expression of 48 immune-related cytokines in the two groups was compared and analyzed in detail. The key cytokines were further identified and clinically predictive models were developed.

Results

We found that 13 cytokines were lowly expressed and one cytokine was highly expressed in the non/low response group, compared with the moderate strong response group at birth. In addition, 9 cytokines were lowly expressed and one cytokine was highly expressed in the non/low response group at 12 months of age. Furthermore, we found that IL-5 and HGF were promising predictors for predicting the immunization response to hepatitis B vaccine in infants, and the combination of the two cytokines showed the best predictive efficiency, with an area under the curve (AUC) value of 0.844.

Conclusion

The present study provides a theoretical basis on cytokines for developing and implementing effective immunotherapies against non/low immune response in infants born to HBsAg-positive mothers.

Hepatitis B vaccine effectiveness among vaccinated children in Africa: a systematic review and meta-analysis

BACKGROUND

Globally, 257 million people have chronic hepatitis. Even though a safe and effective prophylactic vaccine against HBV infection has been available, it causes significant morbidity and mortality. HBV vaccines were designed to improve or modulate the host immune responses. The effectiveness of the vaccine is determined by measuring serum hepatitis B surface antibody (Anti-HBs) level. Therefore, this systematic review aimed to evaluate the effectiveness of hepatitis B vaccine among vaccinated children.

METHODS

Preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines was applied for systematically searching of different databases. Only cross-section studies measuring the level of anti-HBs of vaccinated children were included. The seroprotective level with anti-HBs > 10mIU/ml was extracted. The meta-analysis was performed using statistical software for data sciences (STATA) version 14. Effectiveness estimates were reported as a proportion of anti-HBs level. The heterogeneity between studies was evaluated using the I2 test, and I2 > 50% and/or P < 0.10 was considered significant heterogeneity. Significant publication bias was considered when Egger's test P-value < 0.10. The new castle Ottawa scale was used to assess the quality of the studies.

RESULTS

A pooled sample size of the included papers for meta-analysis was 7430. The pooled prevalence of seroprotected children was 56.95%, with a heterogeneity index (I2) of 99.4% (P < 0.001). 35% of the participants were hypo-responders (10-99mIU/ml) and 21.46% were good responders (> 100mIU/ml). Based on subgroup analysis using country of studies conducted, the highest prevalence of anti-HBs was 87.00% (95% CI: 84.56, 89.44), in South Africa, and the lowest was 51.99% (95% CI: 20.41-83.58), with a heterogeneity index I2 = 70.7% (p = 0.009) in Ethiopia.

CONCLUSION AND RECOMMENDATIONS

Hepatitis B vaccine seroprotective level in the current pooled analysis have suboptimal, which failed to demonstrate consistent effectiveness for global hepatitis B virus elimination plan in 2030. Using consistent age group may have a significant value for the decision of the HB vaccine effectiveness. A significant heterogeneity was observed both in studies conducted in Ethiopia and Egypt. Therefore, the impact of HB vaccination on the prevention of hepatitis B virus infection should be assessed regularly in those countries. Future meta-analysis is needed to investigate all possible vaccines in a separate way of reviewing, which will lead to a strong conclusion and recommendations.

Hepatitis B vaccination status and knowledge, attitude, and practice towards Hepatitis B virus among medical sciences students: A cross-sectional study

BACKGROUND AND AIMS

Healthcare staff are at high risk of occupational exposure to Hepatitis B and other blood-borne diseases. Lack of education about the knowledge of Hepatitis B virus contributes to an increase in cases. This study aims to determine the knowledge of the Hepatitis B virus among the medical professionals in Duhok province, Kurdistan Region of Iraq, and to determine their knowledge of the importance of vaccination.

MATERIALS AND METHODS

This cross-sectional study was conducted in Duhok province, Kurdistan Region of Iraq, among medical science students from November 2022 to February 2023 and a total of 511 students participated in the study. A Self-administered questionnaire comprising 22 items categorized into five sections was distributed to the students either electronically or by paper and pen method. The survey utilized a Five-point Likert scale when assessing respondents' opinions on knowledge, attitude, and practice (KAP). Microsoft Excel and GraphPad Prism 9 were used for statistical analysis.

RESULTS

A total of 511 responses were collected from medical, dental, pharmacy, and laboratory students. The average age of the participants was 20.74 ±1.43 years. Among the respondents, only 96 (18.8%) were fully vaccinated against the Hepatitis B virus (received 3 or more doses of the vaccine), while 294 (57.5%) were not vaccinated. Lack of vaccination programs was the major reason for not receiving a vaccination (n = 182, 62%). About 286 (55.96%) of the participants had good knowledge, attitude, and practice on Hepatitis B, manifesting median scores of 26, 18, and 20, respectively.

CONCLUSION

In our study, half of the students were found to be unvaccinated, mainly due to the absence of vaccination programs. Vaccinated students exhibited better knowledge, attitude, and practice toward the infection than non-vaccinated students. Therefore, we recommend the implementation of a vaccination program as well as training on infection prevention guidelines to increase awareness and encourage vaccination.

Adenosine deaminase augments SARS-CoV-2 specific cellular and humoral responses in aged mouse models of immunization and challenge

Despite numerous clinically available vaccines and therapeutics, aged patients remain at increased risk for COVID-19 morbidity. Furthermore, various patient populations, including the aged can have suboptimal responses to SARS-CoV-2 vaccine antigens. Here, we characterized vaccine-induced responses to SARS-CoV-2 synthetic DNA vaccine antigens in aged mice. Aged mice exhibited altered cellular responses, including decreased IFNγ secretion and increased TNFα and IL-4 secretion suggestive of TH2-skewed responses. Aged mice exhibited decreased total binding and neutralizing antibodies in their serum but significantly increased TH2-type antigen-specific IgG1 antibody compared to their young counterparts. Strategies to enhance vaccine-induced immune responses are important, especially in aged patient populations. We observed that co-immunization with plasmid-encoded adenosine deaminase (pADA)enhanced immune responses in young animals. Ageing is associated with decreases in ADA function and expression. Here, we report that co-immunization with pADA enhanced IFNγ secretion while decreasing TNFα and IL-4 secretion. pADA expanded the breadth and affinity SARS-CoV-2 spike-specific antibodies while supporting TH1-type humoral responses in aged mice. scRNAseq analysis of aged lymph nodes revealed that pADA co-immunization supported a TH1 gene profile and decreased FoxP3 gene expression. Upon challenge, pADA co-immunization decreased viral loads in aged mice. These data support the use of mice as a model for age-associated decreased vaccine immunogenicity and infection-mediated morbidity and mortality in the context of SARS-CoV-2 vaccines and provide support for the use of adenosine deaminase as a molecular adjuvant in immune-challenged populations.

Efficacy of Hepatitis B Vaccination with a Novel Immunostimulatory Sequence Adjuvant (Heplisav-B) in Patients With Inflammatory Bowel Disease

BACKGROUND

Owing to the use of immunosuppressive agents, patients with inflammatory bowel disease (IBD) have an increased risk of vaccine preventable diseases, including infection with hepatitis B virus (HBV). Heplisav-B, an FDA-approved vaccine, is more effective (90% to 100%) than Engerix-B (70.5% to 90.2%) at inducing immunity to HBV in clinical studies. Available data on efficacy of Heplisav-B vaccine in patients with IBD are limited.

METHODS

This retrospective observational study included patients age 18 years and older with ulcerative colitis (UC) or Crohn's disease (CD) who received 1 or 2 doses of Heplisav-B vaccine and had postvaccination serologic testing. Prior to immunization, all participants were seronegative for HBsAb antibodies (HBsAb) measured as <10 IU/mL. Postvaccination HBsAb of ≥10 IU/mL was considered successful vaccination. Patient demographics, disease characteristics, and medications were abstracted.

RESULTS

One hundred six patients were included in the analysis. Median age was 43 years, and 44 (42%) were female. Thirty-nine patients (37%) had UC, whereas 67 (63%) had CD. Eighty-three patients (78.3%) had active immunity after vaccination with Heplisav-B, with median postvaccination HBsAb levels of 114 IU/L. Patients with chronic obstructive pulmonary disease, chronic kidney disease, diabetes mellitus, immunomodulator use, or those on 2 or more of immunosuppressive medications were less likely to respond to Heplisav-B, though these findings were not statistically significant on a multivariate analysis aside from chronic kidney disease.

CONCLUSIONS

Heplisav-B, a 2-dose vaccine, is an effective vaccine for HBV in patients with IBD. In our study, its overall efficacy (78.3%) is greater than that reported for the presently available 3-dose vaccination (Engerix) in patients with IBD.

Recent Advances in Protective Vaccines against Hepatitis Viruses: A Narrative Review

Vaccination has been confirmed to be the safest and, sometimes, the only tool of defense against threats from infectious diseases. The successful history of vaccination is evident in the control of serious viral infections, such as smallpox and polio. Viruses that infect human livers are known as hepatitis viruses and are classified into five major types from A to E, alphabetically. Although infection with hepatitis A virus (HAV) is known to be self-resolving after rest and symptomatic treatment, there were 7134 deaths from HAV worldwide in 2016. In 2019, hepatitis B virus (HBV) and hepatitis C virus (HCV) resulted in an estimated 820,000 and 290,000 deaths, respectively. Hepatitis delta virus (HDV) is a satellite virus that depends on HBV for producing its infectious particles in order to spread. The combination of HDV and HBV infection is considered the most severe form of chronic viral hepatitis. Hepatitis E virus (HEV) is another orally transmitted virus, common in low- and middle-income countries. In 2015, it caused 44,000 deaths worldwide. Safe and effective vaccines are already available to prevent hepatitis A and B. Here, we review the recent advances in protective vaccines against the five major hepatitis viruses.

Immunogenicity and safety of a booster dose of the hepatitis B vaccine HepB-CpG (HEPLISAV-B®) compared with HepB-Eng (Engerix-B®) and HepB-AS04 (Fendrix®) in adults receiving hemodialysis who previously received hepatitis B vaccination and are not seroprotected: Results of a randomized, multicenter phase 3 study

This study compared the immunogenicity and safety of a booster dose of HepB-CpG (HEPLISAV-B® vaccine) with HepB-Eng (Engerix-B®) and HepB-AS04 (Fendrix®) in patients receiving chronic hemodialysis. This was a multicenter, randomized, open-label, phase 3 study of adults receiving hemodialysis with antibodies to HBsAg (anti-HBs) <10 mIU/mL at study entry. The objective was to compare the seroprotection rate (SPR) induced by HepB-CpG with HepB-Eng or HepB-AS04. The SPR was defined as the percentage of patients with anti-HBs ≥10 mIU/mL post-vaccination. At 20 sites in Germany, 155 participants were randomized: HepB-CpG = 54; HepB-Eng = 50; and HepB-AS04 = 51. Of the 149 participants in the modified intention-to-treat population, 76.5% had not previously responded to at least one series of hepatitis B vaccine. Based on a post hoc analysis, the SPR in HepB-CpG recipients (52.8%; 95% confidence interval [CI]: 38.6%, 66.7%) was significantly higher than in HepB-Eng recipients (32.6%; 95% CI: 19.5%, 48.0%), and non-inferior to that in HepB-AS04 recipients (43.1%; 95% CI: 29.3%, 57.8%). Local post-injection reactions occurred in significantly fewer HepB-CpG (9.3%) than HepB-AS04 recipients (31.4%; p = .007) and at a similar rate to HepB-Eng recipients (8.2%). Systemic post-injection reactions in HepB-CpG recipients (18.5%) were similar to the HepB-AS04 group (19.6%) and higher than in the HepB-Eng group (12.2%). In this difficult-to-immunize population, a booster dose of HepB-CpG induced significantly higher levels of seroprotection than HepB-Eng with a similar safety profile. The higher levels of immunogenicity were not accompanied by higher levels of local post-injection reactions compared with HepB-AS04.

Generation and Utilization of a Monoclonal Antibody against Hepatitis B Virus Core Protein for a Comprehensive Interactome Analysis

Hepatitis B virus (HBV) core antigen (HBc) is a structural protein that forms the viral nucleocapsid and is involved in various steps of the viral replication cycle, but its role in the pathogenesis of HBV infection is still elusive. In this study, we generated a mouse monoclonal antibody (mAb) against HBc and used it in antibody-based in situ biotinylation analysis in order to identify host proteins that interact with HBc. HBc antigen was produced with a wheat germ cell-free protein synthesis system and used to immunize mice. Among the established hybridoma clones, a single clone (mAb #7) was selected and further characterized for its ability in the antibody-based in situ biotinylation analysis to collect host proteins that are in the vicinity of HBc. Using mass spectrometry, we identified 215 HBc-interacting host proteins, three of which bind HBc most significantly under hypoxic conditions. Our results indicate that mAb #7 can be used to systematically identify host proteins that interact with HBc under pathophysiological conditions, and thus may be useful to explore the molecular pathways involved in HBV-induced cytopathogenesis.

Effects of the age of vaccination on the humoral responses to a human papillomavirus vaccine

Adult vaccination programs are receiving increasing attention however, little is known regarding the impact of age on the maintenance of the immune response. We investigated this issue in the context of a human papillomavirus (HPV) vaccination program collecting real-world data on the durability of humoral immunity in 315 female subjects stratified according to vaccination age (adolescents and adults) and sampled at early or late time points after the last vaccine dose. HPV-specific IgGs, but not memory B cells, were induced and maintained at higher levels in subjects vaccinated during adolescence. Nonetheless, antibody functions waned over time to a similar degree in adolescents and adults. To shed light on this phenomena, we analyzed quantitative and qualitative properties of lymphocytes. Similar biochemical features were observed between B-cell subsets from individuals belonging to the two age groups. Long term humoral responses toward vaccines administered at an earlier age were comparably maintained between adolescents and adults. The percentages of naïve B and CD4⁺ T cells were significantly higher in adolescents, and the latter directly correlated with IgG titers against 3 out of 4 HPV types. Our results indicate that age-specific HPV vaccine responsiveness is mostly due to quantitative differences of immune cell precursors rather than qualitative defects in B cells. In addition, our results indicate that adults also have a good humoral immunogenic profile, suggesting that their inclusion in catch-up programmes is desirable.

12 Months Persistent Immunogenicity after Hepatitis B Vaccination in Patients with Type 2 Diabetes and Immunogenicity of Revaccination in Non-Responders: An Open-Label Randomized Controlled Trial

BACKGROUND

In initial studies, the immunogenicity and safety of hepatitis B vaccines in patients with diabetes has been assessed in China.

METHODS

In six township health centers in Gansu Province, 232 diabetic patients and 77 healthy people were allocated to receive two 3-dose hepatitis B vaccines (Group D20SC 0-1-6; Group D20CHO 0-1-6; Group ND20SC 0-1-6). Participants were followed up at 12 months after being fully vaccinated. One dose of the vaccine was randomly administered to non-responders. Chi-square test was used to compare the differences in response rate between two groups.

RESULTS

The anti-HBs response rates of three groups decreased from 84.1%, 89.1% and 88.3% at one month to 64.6%, 79.8% and 71.4% at twelve months. There was no statistical difference in the immune response rates between Group D20SC 0-1-6 and Group ND20SC 0-1-6; however, that of Group D20CHO 0-1-6 was higher than that of Group D20SC 0-1-6. After revaccination, the geometric mean concentrations were 491.7 mIU/mL and 29.7 mIU/mL after using vaccines containing 60 μg and 20 μg HBsAg.

CONCLUSIONS

At 12 months, immune response in diabetic patients were not significantly different from that in healthy people. Revaccination with one dose of hepatitis B vaccine containing 60 μg HBsAg for non-responders was more satisfactory.

Vaccination of older adults: Influenza, pneumococcal disease, herpes zoster, COVID-19 and beyond

Preserving good health in old age is of utmost importance to alleviate societal, economic and health care-related challenges caused by an aging society. The prevalence and severity of many infectious diseases is higher in older adults, and in addition to the acute disease, long-term sequelae, such as exacerbation of underlying chronic disease, onset of frailty or increased long-term care dependency, are frequent. Prevention of infections e.g. by vaccination is therefore an important measure to ensure healthy aging and preserve quality of life. Several vaccines are specifically recommended for older adults in many countries, and in the current SARS-CoV-2 pandemic older adults were among the first target groups for vaccination due to their high risk for severe disease. This review highlights clinical data on the influenza, Streptococcus pneumoniae and herpes zoster vaccines, summarizes recent developments to improve vaccine efficacy, such as the use of adjuvants or higher antigen dose for influenza, and gives an overview of SARS-CoV-2 vaccine development for older adults. Substantial research is ongoing to further improve vaccines, e.g. by developing universal influenza and pneumococcal vaccines to overcome the limitations of the current strain-specific vaccines, and to develop novel vaccines against pathogens, which cause considerable morbidity and mortality in older adults, but for which no vaccines are currently available. In addition, we need to improve uptake of the existing vaccines and increase awareness for life-long vaccination in order to provide optimal protection for the vulnerable older age group.

Immunogenicity and Safety of a 3-Antigen Hepatitis B Vaccine vs a Single-Antigen Hepatitis B Vaccine: A Phase 3 Randomized Clinical Trial

IMPORTANCE

There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection.

OBJECTIVES

To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and compare safety and reactogenicity between 3A-HBV and 1A-HBV vaccines.

DESIGN, SETTING, AND PARTICIPANTS

This phase 3, double-blinded, randomized clinical trial included healthy adults aged 18 to 45 years randomized to 1 of three 3A-HBV groups or 1 control group receiving 1A-HBV. The trial was conducted at 37 community clinics and academic hospitals in Canada, Europe, the United Kingdom, and the United States between December 2017 and October 2019. Participants were followed up for 48 weeks after the first vaccination.

INTERVENTIONS

Intramuscular administration of 3A-HBV (10 μg) or 1A-HBV (20 μg) on days 0, 28, and 168.

MAIN OUTCOMES AND MEASURES

Geometric mean concentration (GMC) of serum hepatitis B surface antibodies (anti-HBs) and proportion of participants achieving seroprotection.

RESULTS

Of 2838 participants, 1638 (57.8%) were women, 2595 (91.5%) were White, and 161 (5.7%) were Black or African American. A total of 712 participants (25.1%) were randomized to the 1A-HBV group and 2126 (74.9%) to 3A-HBV. The mean (SD) age at informed consent was 33.5 (8.0) years. The study demonstrated 3A-HBV lot-to-lot consistency, as the 2-sided 95% CIs for each pairwise comparison for the anti-HBs GMC ratios were within 0.67 and 1.50 (eg, adjusted GMC ratio, lot A vs lot B: 0.82; 95% CI, 0.67-1.00; lot A vs lot C: 0.95; 95% CI, 0.78-1.15; lot B vs lot C: 1.16; 95% CI, 0.95-1.41). The SPR of the pooled 3A-HBV was noninferior to 1A-HBV and higher than 1A-HBV after 2 vaccinations at day 168 (90.4% [95% CI, 89.0%-91.8%] vs 51.6% [95% CI, 47.5%-55.6%]) and 3 vaccinations at day 196 (99.3% [95% CI, 98.7%-99.6%] vs 94.8% [95% CI, 92.7%-96.4%]). The mean GMC of anti-HBs with 3A-HBV was 7.9 times higher after 2 vaccinations at day 168 and 3.5 times higher after 3 vaccinations at day 196 compared with 1A-HBV (after 2 vaccinations, 3A-HBV: GMC, 118.7 mIU/mL; 95% CI, 108.0-129.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: GMC, 15.0 mIU/mL; 95% CI, 12.9-17.5 mIU/mL; SE, 1.0 mIU/mL; after 3 vaccinations, 3A-HBV: GMC, 5442.4 mIU/mL; 95% CI, 4967.0-5963.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: 1567.2 mIU/mL; 95% CI, 1338.0-1834.0 mIU/mL; SE, 1.0 mIU/mL). Rates of local and systemic reactogenicities were higher with 3A-HBV compared with 1A-HBV (local: 1805 of 2124 [85.0%] vs 469 of 712 [65.9%]; systemic: 1445 [68.0%] vs 428 [60.1%]). Vaccine discontinuation due to adverse events (AE) was uncommon, and serious AEs were infrequent, reported in 42 participants (2.0%) and 3 participants (0.4%) in the 3A-HBV and 1A-HBV groups, respectively.

CONCLUSIONS AND RELEVANCE

In this study, consistently higher antibody concentrations and SPRs were found with 3A-HBV after 2 and 3 doses vs 1A-HBV in adults aged 18 to 45 years old. The safety and efficacy of 3A-HBV shows its usefulness for the prevention of hepatitis B in young healthy adults.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03408730; EU Clinical Trials Number: 2017-001820-22.

Delayed Antibody and T-Cell Response to BNT162b2 Vaccination in the Elderly, Germany

We detected delayed and reduced antibody and T-cell responses after BNT162b2 vaccination in 71 elderly persons (median age 81 years) compared with 123 healthcare workers (median age 34 years) in Germany. These data emphasize that nonpharmaceutical interventions for coronavirus disease remain crucial and that additional immunizations for the elderly might become necessary.

Comparative cost-effectiveness of a 2-dose versus 3-dose vaccine for hepatitis B prevention in selected adult populations

The hepatitis B virus is highly infectious and can cause incurable liver disease, leading to high morbidity rates, increased healthcare utilization, and high mortality. Multiple preventative hepatitis B vaccine options have been available for decades, but adherence to the traditional 6-month vaccine schedule for the approved 3-dose series remains low in adult populations at risk of hepatitis B exposure. A 2-dose hepatitis B vaccine (HEPLISAV-B) approved by the US Food and Drug Administration in 2017 induces rapid seroprotection within 1 month and has a safety profile comparable to a commonly used 3-dose vaccine. In a previous cost-effectiveness study, HEPLISAV-B had a favorable cost-effectiveness profile for multiple at-risk populations. The goal of the current analysis was to update and extend previous findings by evaluating cost-effectiveness of HEPLISAV-B compared with a 3-dose vaccine (Engerix-B) in selected adult populations, including patients with diabetes, chronic liver or kidney disease, end-stage renal disease, healthcare personnel, travelers to countries with endemic hepatitis B, and a public health population. Cost-effectiveness was measured as incremental cost-effectiveness ratios using a health economics Markov model that accounts for adherence rates, seroprotection rates, healthcare costs, and current pricing considerations. Patients progressed between a series of health states, and the difference in lifetime spending and survival for individuals receiving either HEPLISAV-B or Engerix-B was estimated from the perspective of a US managed care payer, HEPLISAV-B had favorable cost-effectiveness profiles for patients with diabetes, healthcare personnel, travelers, and patients with chronic liver disease and dominant incremental cost-effectiveness ratios for patients with chronic kidney disease and end-stage renal disease. A probabilistic sensitivity analysis supported the robustness of the cost-effectiveness profiles, and an additional analysis indicated that HEPLISAV-B was cost-effective in the general adult population. Overall, HEPLISAV-B was cost-effective in multiple adult populations recommended for HBV vaccination in the United States.

Immunomodulation by the Commensal Microbiome During Immune-Targeted Interventions: Focus on Cancer Immune Checkpoint Inhibitor Therapy and Vaccination

Emerging evidence in clinical and preclinical studies indicates that success of immunotherapies can be impacted by the state of the microbiome. Understanding the role of the microbiome during immune-targeted interventions could help us understand heterogeneity of treatment success, predict outcomes, and develop additional strategies to improve efficacy. In this review, we discuss key studies that reveal reciprocal interactions between the microbiome, the immune system, and the outcome of immune interventions. We focus on cancer immune checkpoint inhibitor treatment and vaccination as two crucial therapeutic areas with strong potential for immunomodulation by the microbiota. By juxtaposing studies across both therapeutic areas, we highlight three factors prominently involved in microbial immunomodulation: short-chain fatty acids, microbe-associate molecular patterns (MAMPs), and inflammatory cytokines. Continued interrogation of these models and pathways may reveal critical mechanistic synergies between the microbiome and the immune system, resulting in novel approaches designed to influence the efficacy of immune-targeted interventions.

COVID-19 dynamics after a national immunization program in Israel

Studies on the real-life effect of the BNT162b2 vaccine for Coronavirus Disease 2019 (COVID-19) prevention are urgently needed. In this study, we conducted a retrospective analysis of data from the Israeli Ministry of Health collected between 28 August 2020 and 24 February 2021. We studied the temporal dynamics of the number of new COVID-19 cases and hospitalizations after the vaccination campaign, which was initiated on 20 December 2020. To distinguish the possible effects of the vaccination on cases and hospitalizations from other factors, including a third lockdown implemented on 8 January 2021, we performed several comparisons: (1) individuals aged 60 years and older prioritized to receive the vaccine first versus younger age groups; (2) the January lockdown versus the September lockdown; and (3) early-vaccinated versus late-vaccinated cities. A larger and earlier decrease in COVID-19 cases and hospitalization was observed in individuals older than 60 years, followed by younger age groups, by the order of vaccination prioritization. This pattern was not observed in the previous lockdown and was more pronounced in early-vaccinated cities. Our analysis demonstrates the real-life effect of a national vaccination campaign on the pandemic dynamics.

Fendrix® Vaccine Effectiveness in Healthcare Workers Who Are Non-Responsive to Engerix B® Vaccination

Hepatitis B (HBV) is a pathogen virus with transmission mechanisms that include contact with the infected blood or bodily fluids of the infected organism. Nowadays, healthcare workers are one of the most exposed groups to HBV. Conventionally, completing a vaccine series dosage with Engerix B^® lowers this risk by providing workers with immunity to the virus. However, through the years, we have encountered nonresponsive health personnel to the Engerix B^® vaccine; hence, the Occupational Health Service of Poniente Hospital studied the Fendrix^® adjuvanted vaccine as an alternative vaccine to develop immunological responses in healthcare workers who do not respond to vaccination with Engerix B^®. In our study, we employed a vaccination schedule with the Fendrix^® vaccine, performing serology tests on the cases after the application of each dose. The results obtained showed humoral immunity in 92.3% of the cases, with a remarkable increase in antibody titer after the first doses. These encouraging results support the future inclusion of this vaccine as one possible alternative for the immunization to HBV for healthcare workers nonresponsive to Engerix B^®.

[Hepatitis B vaccine and liver cancer]

Hepatitis B Virus (HBV) chronic infection contributes to a high risk of hepatocellular cancer (HCC) development. HBV is a strong cancer inducer, due to natural history of infection, virological characteristics and viral DNA integrations events in host genome. Prolonged infection and high viral loads, particularly frequent in patients infected in childhood, are risk factors of HCC development for patients with HBV chronic infection. A HBV vaccine, based on immunization against the surface protein HBs, showed a strong efficacy to prevent chronic HBV infection. The development of universal neonatal vaccination programmes contributed to the decrease of HBV chronic infection incidence in children of high endemic areas. Although HBs antibodies levels diminished years after vaccination, HBV neonatal vaccination programmes led to a lower incidence of chronic HBV infection among young adults. The decrease of HBV chronic infection incidence was associated to a reduction of HCC incidence in children and young adults from areas with a high prevalence of HBV infection.

A simple clinical score to identify likely hepatitis B vaccination non-responders - data from a retrospective single center study

Background

About 10% of Hepatitis B vaccinated individuals mount no protective antibody levels against the hepatitis B surface antigen (HBs-Ag). Older age at primary immunization, obesity and smoking have previously been reported as risk factors associated with vaccine non-response. Here we tested whether these factors alone may allow selecting subjects that benefit from individualized immunization schedules.

Methods

Retrospective database analysis screening > 15,000 individual anti-HBs-IgG measurements. Non-responders (NR; anti-HBs-IgG < 10 IU/L) and low-responders (LR; anti-HBs-IgG 10–100 IU/L) were identified. Vaccine type, demographics, lifestyle, and immunological factors (leucocyte subset counts) were compared between NR, LR, and responders (R).

Results

We identified 113 LR/NR and compared them to 134 vaccine responders. We confirmed higher median age at primary vaccination (24.0 (R) vs. 30.5 (NR) vs. 31 (LR) years, p = 0.001), higher median BMI (23.2 kg/m² (R) vs. 23.4 kg/m² (NR) vs. 25.1 kg/m² (LR), p = 0.001) and being a smoker (% smokers: 30.8% (R) vs. 57.1% (NR) vs. 52.5% (LR), p = 0.01) as factors negatively associated with anti-HBs-IgG levels. In a ROC analysis including these factors in a 6-point score, a high score predicted non-response with a specificity of 85% but at low sensitivity (47%).

Conclusion

A simple clinical risk score based on age, obesity, and smoking identifies individuals with a high likelihood of vaccine failure. Non-responders with a low score are candidates for in-depth analyses to better understand the immunological causes of HBV vaccine non-response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05634-y.

Efficacy and Safety of a 3-Antigen (Pre-S1/Pre-S2/S) Hepatitis B Vaccine: Results of a Phase 3 randomized clinical trial in the Russian Federation

Background

This study compares the immunogenicity and safety of a 3-antigen (S/pre-S1/pre-S2) hepatitis B (HepB) vaccine (3AV), to a single antigen vaccine (1AV) in adults to support the registration of 3AV in Russia.

Methods

We conducted a randomized, double-blind, comparative study of 3-dose regimens of 3AV (10 μg) and 1AV (20 µg) in adults aged 18–45 years. We evaluated immunogenicity based on hepatitis B surface (HBs) antibody titers at days 1, 28, 90, 180, and 210, adverse and serious adverse events (SAEs) to study day 210. The primary outcome was based on the difference in rates of seroconversion at day 210 (lower bound 95% confidence interval [CI]: > − 4%). Secondary outcomes were seroprotection rates (SPR), defined as anti-HBs ≥10 mIU/mL and anti-HBs geometric mean concentration (GMC).

Results

Rate of seroconversion in 3AV (100%) was noninferior to 1AV (97.9%) at study day 210 (difference: 2.1%, 95% CI: −2.0, 6.3%]) but significantly higher at study day 28. SPR at study day 210 was >97% in both arms. Anti-HBs titers were significantly higher at study days 90 (P = .001) and 180 (P = .0001) with 3AV. Sex, age, and body mass index (BMI) had no impact on anti-HBs titers. The rates of local reactions related to vaccination were similar between vaccine arms (3AV vs 1AV) after the first (30% vs 18.8%, P = .15), second (20.0% vs 14.6%, P = .33), and third vaccination (14.9% vs 23.4%, P = .22). No SAEs were reported.

Conclusions

3AV was noninferior to 1AV. 3AV induced high SPR, and there were no safety concerns.

Clinical Trials Registration. NCT04209400.

Maintaining Hepatitis B Protection in Immunocompromised Pediatric Rheumatology and Inflammatory Bowel Disease Patients

OBJECTIVE

Hepatitis B virus (HBV) infection remains a significant public health challenge, particularly for immunocompromised patients. Our aim was to evaluate the serologic immunity in immunocompromised rheumatology and inflammatory bowel disease (IBD) patients, assess factors for serologic nonimmunity, and evaluate their response to 1 HBV booster dose.

METHODS

Immunocompromised rheumatology and IBD patients with completed HBV screening were identified. A chart review was performed to collect demographics, clinical information, baseline HBV serology results, and serologic response to booster vaccination. Serologic nonimmunity was defined as a negative/indeterminate hepatitis B surface antibody (anti-HBs) level.

RESULTS

Among 580 patients, 71% were nonimmune. The highest portion of nonimmune patients were 11-18 years old (P = 0.004). There was no significant difference between immune and nonimmune patients with regards to diagnosis (P = 0.34), age at diagnosis (P = 0.64), duration of treatment (P = 0.07), or type of medications (P = 0.08). Sixty-two percent of those who received a booster vaccine were rescreened, and most (68%) seroconverted. In those 18 years or older, only half seroconverted.

CONCLUSION

Results of this study support the benefit of HBV screening in immunosuppressed patients. Beginning at age 11 years, most patients lacked serologic immunity to HBV. Seroconversion for most patients 11-18 years occurred after 1 booster vaccine. Thus, for immunocompromised patients without recent HBV serologic data, obtaining the HBV serology beginning at age 11 years might be considered. Those 18 years and older were least likely to seroconvert after 1 booster, indicating that they may benefit from receiving the 3-dose HBV vaccine series.

Efficacy and Safety of Revaccination against Tetanus, Diphtheria, Haemophilus influenzae Type b and Hepatitis B Virus in a Prospective Cohort of Adult Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Data on immunogenicity and safety of the recommended revaccination schedule against diphtheria, tetanus, poliomyelitis, pertussis, Haemophilus influenzae type b (Hib), and hepatitis B in adult allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are limited. This prospective single-center cohort study (April 2014 to March 2018) included adult allo-HSCT recipients referred to a dedicated vaccinology consultation and vaccinated with the pediatric combined diphtheria, tetanus, acellular pertussis, hepatitis B virus, inactivated poliovirus, and Haemophilus influenzae type b (DTaP(±HB)-IPV-Hib) vaccine (3 doses 1 month apart, booster dose 1 year later). The proportion of responders to tetanus, diphtheria, Hib, and hepatitis B vaccine and geometric mean concentrations (GMCs) of antibodies were assessed before and up to 24 months after vaccination. A total of 106 patients were vaccinated at a median (interquartile range) time of 12.4 (10 to 18.4) months post-transplant. At 5.3 (4.8 to 6.6) and 23.1 (21.1 to 25.1) months after vaccine initiation, high and sustained rates of protective antibody titers were achieved for tetanus (97.8% [95% confidence interval (95% CI), 92.4% to 99.7%], n = 91/93 and 100% [95% CI, 92% to 100%], n = 44/44), diphtheria (94.6% [95% CI, 87.9% to 98.2%], n = 88/93 and 90.9% [95% CI, 78.3% to 97.5%], n = 40/44), Hib (96.6% [95% CI, 90.4% to 99.3%], n = 85/88 and 93% [95% CI, 80.9% to 98.5%], n = 40/43), and hepatitis B (83.5% [95% CI, 73.5% to 90.9%], n = 66/79 and 81.1% [95% CI, 64.8% to 92%], n = 30/37). Underlying disease, stem cell source, chronic graft-versus-host-disease, and extracorporeal photopheresis differentially influenced GMCs of tetanus, diphtheria, and hepatitis B antibodies after 3 doses but not in the long term (24 months). Six (5.7%) patients experienced mild side effects. The pediatric DTaP(±HB)-IPV-Hib vaccine was safe and effective in eliciting a sustained protective humoral response in adult allo-HSCT recipients. Hepatitis B revaccination might be optimized by using higher antigen doses.

The SENIEUR protocol and the efficacy of hepatitis B vaccination in healthy elderly persons by age, gender, and vaccine route

BACKGROUND

Reduced response to hepatitis B vaccines is associated with aging, confounding and comorbid conditions, as well as inadvertent subcutaneous (SC) inoculation. We hypothesized that the antibody and T cell-mediated immune responses (T-CMI) of elderly adults to a vaccine intended for intramuscular (IM) administration would be attenuated when deposited into SC fat, independent of confounding conditions.

RESULTS

Fifty-two healthy, community dwelling elderly adults (65-82 years), seronegative for HBV, were enrolled in the SENIEUR protocol as a strictly healthy population. These seniors were randomized to receive a licensed alum-adjuvanted recombinant HBV vaccine either SC or IM, with the inoculum site verified by imaging. The response rates, defined as hepatitis B surface antibodies (HBsAb) ≥10 IU/L, were significantly lower in the elderly than in young adults, a group of 12, healthy, 21-34-year-old volunteers. Moreover, elderly participants who received the vaccine IM were significantly more likely to be responders than those immunized SC (54% versus 16%, p = 0.008). The low seroconversion rate in the IM group progressively declined with increasing age, and responders had significantly lower HBsAb titers and limited isotype responses. Moreover, T-CMI (proliferation and cytokine production) were significantly reduced in both percentage of responders and intensity of the response for both Th1 and Th2 subsets in the elderly.

CONCLUSIONS

Our data demonstrate the blunted immunogenicity of SC inoculation as measured by peak titers and response rates. Further, the qualitative and quantitative deficits in B- and T-CMI responses to primary alum adjuvanted protein antigens persisted even in strictly healthy elderly populations with verified IM placement compared to younger populations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT04162223. Registered 14 November 2019. Retrospectively registered.

Helminth infections and immunosenescence: The friend of my enemy

Age-associated alterations of the immune system, which known as "immunosenescence", is characterized by a decline in innate and adaptive immunity, which leading to increased susceptibility to age-associated diseases, such as infectious diseases, rheumatic disease and malignancies. On the other hand, helminth infections are among the most prevalent infections in older individuals, especially in the nursing homes. Most of helminth infections have minor clinical symptoms and usually causing chronic infections without treatment. Nevertheless, chronic helminthiasis alters immune responses somewhat similar to the immunosenescence. Some similarities also exist between helminth infections and immunosenescence: 1) both of them led to declining the immune responses; 2) undernutrition is a consequence of immunosenescence and helminthiasis; 3) vaccine efficacy declines in aging and individuals with helminth infections; 4) increase incidence and prevalence of infectious diseases in the elder individuals and patients with helminth infections; and 5) both of them promote tumorigenesis. Hence, it is probable that helminth infections in the elderly population can intensify the immunosenescence outcomes due to the synergistic immunoregulatory effects of each of them. It would be suggested that, diagnosis, treatment and prevention of helminth infections should be more considered in older individuals. Also, it would be suggested that helminths or their antigens can be used for investigation of immunosenescence because both of them possess some similarities in immune alterations. Taken together, this review offers new insights into the immunology of aging and helminth infections.

Serological response to three alternative series of hepatitis B revaccination (Fendrix, Twinrix, and HBVaxPro-40) in healthy non-responders: a multicentre, open-label, randomised, controlled, superiority trial

BACKGROUND

Serological non-response can be present after hepatitis B vaccination in healthy adults. We aimed to establish which of three revaccination regimens is most effective at inducing protective immunity METHODS: Healthy adults (aged 18-80 years) from 16 Dutch centres (13 public health services, two university hospitals, and one travel clinic) were included in this multicentre, parallel group, randomised, controlled, superiority trial. The inclusion criterion was vaccine non-response (hepatitis B surface antibody [anti-HBs] titre <10 IU/L) after a primary series with three doses of one type of recombinant vaccine against hepatitis B virus (either HBVaxPro-10 or Engerix-B at months 0, 1, and 6). Participants were individually randomly assigned (1:1:1:1) to a vaccination series of repeated initial vaccination (HBVaxPro 10 μg or Engerix-B 20 μg) as the control, or to Twinrix 20 μg, Fendrix 20 μg, or HBVaxPro 40 μg. We used a web-based randomisation programme, stratified by centre, with a block size of four. Participants and centres were unmasked to assignment after randomisation. Laboratory staff and investigators were masked to vaccine-group assignment. All revaccination schedules were identical, with intramuscular vaccinations at 0, 1, and 2 months. Anti-HBs was measured at 0, 1, 2, and 3 months. The primary outcome was the percentage of responders (anti-HBs titres ≥10 IU/L) at 3 months. Immunogenicity and safety analyses were based on an intention-to-vaccinate analysis, the immunogenicity analysis with last observation carried forward for missing data, and the Bonferroni and the Benjamini-Hochberg method were applied to correct for multiple testing. The trial was registered in the Dutch National Trial Register and inclusion has been stopped (identifier NL3011; EudraCT-number 2011-005627-40).

FINDINGS

The participants were recruited between Nov 1, 2012, and Sept 1, 2017. 480 participants were randomly assigned and included in intention-to-vaccinate analyses: 124 (26%) to control, 118 (25%) to Twinrix, 114 (24%) to HBVaxPro-40, and 124 (26%) to Fendrix. At month 3 the percentage of responders was 83 (67%) of 124 (95% CI 57·9-75·1 in the control group, 94 (80%) of the 118 (71·3-86·5) in the Twinrix group, 95 (83%) of 114 (75·2-89·7) in the HBVaxPro-40 group, and 108 (87%) of 124 (79·9-92·4) in the Fendrix group. Compared with the control group, the percentage of responders was superior for the HBVaxPro-40 group (adjusted difference 21·6% [95% CI 10·4-32·7], p=0·0204 [Bonferroni corrected p value]) and the Fendrix group (26·3% [15·4-37·3], p=0·0006), but not the Twinrix group (25·0% [13·0-37·0]; p=0·0846). One serious adverse event occurred (herpes zoster ophthalmicus) in the Fendrix group, which was not attributed to the vaccine.

INTERPRETATION

Revaccinating healthy non-responders with Fendrix or HBVaxPro-40 resulted in significantly higher proportions of responders and therefore indication for these vaccines should be expanded to enable revaccination of non-responders.

FUNDING

National Institute for Public Health and the Environment.

Immunogenicity and safety of a 2-dose hepatitis B vaccine, HBsAg/CpG 1018, in persons with diabetes mellitus aged 60-70 years

BACKGROUND

Hepatitis B virus (HBV) remains a major public health issue, although it is a vaccine-preventable disease. Adults with diabetes are at greater risk of contracting HBV than the general population. Commonly used 3-dose HBV vaccines have reduced immunogenicity in older individuals and in those with diabetes mellitus.

METHODS

In this post hoc analysis of a phase 3 clinical trial, participants with type 2 diabetes mellitus aged 60-70 years received either 2-dose HBsAg/CpG 1018 (HEPLISAV-B®, n = 327) at 0 and 4 weeks and placebo at 24 weeks or 3-dose HBsAg/alum (Engerix-B®, n = 153) at 0, 4, and 24 weeks. Immunogenicity, including seroprotection rate (SPR) at week 28, and safety were assessed by subgroup (sex, body mass index, and smoking status). SPR was defined as antibody against hepatitis B surface antigen serum concentration ≥10 mIU/mL.

RESULTS

The SPR at week 28 was significantly higher with HBsAg/CpG 1018 (85.8% [235/274]) than with HBsAg/alum (58.5% [76/130]) in the per-protocol analysis, for an overall difference of 27.3% (95% CI, 18.0-36.8). SPRs with HBsAg/CpG 1018 were consistently markedly higher compared with HBsAg/alum, regardless of sex, body mass index, or smoking status. Adverse events and deaths were comparable between groups.

CONCLUSIONS

Two-dose HBsAg/CpG 1018 provides a higher level of seroprotection against HBV than does a 3-dose vaccine (HBsAg/alum) with a similar safety profile in patients aged 60-70 years with type 2 diabetes mellitus. Study identifier: NCT02117934.

Hepatitis B Surface Antibody Titers at One and Two Years after Hepatitis B Virus Vaccination in Healthy Young Japanese Adults

Objective Since healthcare providers face an increased risk of hepatitis B virus (HBV) infection because of their work, vaccination plays a critical role in preventing HBV transmission. However, the duration for which acquired HBV surface antibodies (anti-HBs) persist remains unknown. To evaluate the primary immunologic response to HBV vaccination and its persistence in healthy Japanese adolescents. Methods In total, 690 young adults underwent HBV vaccination with a three-dose schedule. The primary response was determined by the anti-HBs titers at 1-2 months after the final dosage. Subjects with anti-HBs titers of <10, 10-100, and >100 mIU/mL were classified as "non-responders," "low-responders," and "sufficient responders," respectively. Anti-HB titers were re-measured at 1 or 2 years after vaccination. Results First, 95.8% and 72.8% of the subjects had anti-HBs titers of >10 and >100 mIU/mL, respectively, as a primary response. The anti-HBs titers measured at 1 and 2 years after vaccination were significantly correlated with those of the primary response (1 year: r=0.893, p<0.0001; 2 years: r=0.902, p<0.001). Most subjects with a titer of >100 mIU/mL at the primary response maintained an anti-HBs titer of >10 mIU/mL [1 year after vaccination, 208/209 (99.5%); 2 years after vaccination, 72/81 (90.1%)]. However, in subjects with a primary response of 10-100 mIU/mL the anti-HBs titer frequently declined; 17/38 (44.7%) and 9/10 (90.0%) subjects had a titer of <10 mIU/mL at 1 and 2 years, respectively. Conclusion The primary response was associated with the anti-HBs titers at 1 and 2 years after vaccination, and the anti-HBs titers of 54.2% of the low responders were not maintained for 2 years, even if they were vaccinated as healthy young adults.

Improved Antibody Response to Three Additional Hepatitis B Vaccine Doses Following Primary Vaccination Failure in Patients with Inflammatory Bowel Disease

BACKGROUND

Studies have shown the efficacy of hepatitis B (HBV) vaccination in patients with inflammatory bowel disease (IBD) is impaired, but few data exist regarding the effectiveness of revaccination strategies following primary vaccination failure. Our aim was to analyze the association between administration of additional vaccine doses and hepatitis B surface antibody (HBsAb) seroconversion.

METHODS

This is a retrospective cohort study. Inclusion criteria are as follows: age ≥ 18, diagnosis of Crohn's disease (CD) or ulcerative colitis (UC), inadequate HBsAb < 10 IU/L following initial HBV vaccination series, subsequent administration of 1-3 additional doses of HBV vaccine with follow-up serum HBsAb measurements. Patients were stratified into groups of ≤ 2 or 3 doses received. Primary outcome was achieving HBsAb > 10 IU/L. Outcomes were stratified by age ≥ or < 40 years. We performed logistic and linear multivariable regression analyses for categorical and continuous data.

RESULTS

The study cohort consists of (n = 149) 54.4% women; 77.9% white; 72.6% with CD, with mean age: 46.2. Patients of all ages and age ≥ 40 years, who received 3 additional doses of vaccine, were more likely to achieve seroprotective HBsAb levels than patients who received 1 or 2 doses (OR 1.77, P = 0.01; OR 1.9, P = 0.03, respectively, after adjusting for age, sex, race, immunosuppressive medication exposure, time between vaccine/titer).

CONCLUSIONS

Following initial HBV vaccination failure, patients with IBD of all ages are more likely to develop seroprotective levels of HBsAb following 3 additional vaccine doses, rather than 1 or 2 alone. In patients who fail primary HBV vaccination, providers should consider a more aggressive revaccination strategy with an additional 3-dose series.

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.

Immunogenicity and safety of 4 vs. 3 standard doses of HBV vaccination in HIV-infected adults with isolated anti-HBc antibody

Background

Presence of isolated anti-HBc antibody is common in HIV-infected patients in endemic areas and could be caused by prior HBV infection with loss of anti-HBs antibody. The role of vaccination in these patients remains controversial and is based largely on limited and low quality data. We, therefore, conducted this study to determine immunogenicity and safety of 4 vs. 3 standard doses of HBV vaccination in HIV-infected adults with isolated anti-HBc antibody.

Methods

An open-label, randomized controlled trial was conducted among HIV-infected patients visiting HIV clinic of the Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand between July and September 2017. Inclusion criteria included ≥ 18 years of age, currently on a stable antiretroviral regimen, CD4+ cell count ≥ 200 cells/mm³, plasma HIV-1 RNA < 20 copies/mL, and isolated anti-HBc antibody. The participants were randomized to receive either 3 standard doses (20 µg at month 0, 1, 6) or 4 standard-doses (20 µg at month 0, 1, 2, 6) of IM HBV vaccination, and were evaluated for anamnestic response at week 4 and vaccine response at week 28.

Results

Of the 97 patients screened, 54 (32 male, mean age of 46 years) were enrolled and 27 were allocated to each of the vaccination groups. Anamnestic response occurred in 25.9% vs. 33.3% in 3-dose group vs. 4-dose group, respectively (p = 0.551). The vaccine response rates at week 28 were 85.2% in 3-dose group vs. 88.9% in 4-dose group (p = 1.000); geometric mean titer of anti-HBs antibody at week 28 was 63.8 and 209.8 mIU/mL in 3-dose group and 4-dose group, respectively (p = 0.030). No adverse events were reported.

Conclusions

An anamnestic response occurred in one-third of Thai HIV-infected patients with isolated anti-HBc antibody who received one dose of HBV vaccination; however, the majority were still unprotected. The use of either 3 or 4 standard-doses of vaccination was highly effective and should be recommended in all HIV-infected individuals with isolated anti-HBc antibody.

Trial registration ClinicalTrials.gov; NCT03212911. Registered 11 July 2019, https://clinicaltrials.gov/ct2/show/NCT03212911

Electronic supplementary material

The online version of this article (10.1186/s12981-019-0225-3) contains supplementary material, which is available to authorized users.

Sulfated archaeol glycolipids: Comparison with other immunological adjuvants in mice

Archaeosomes are liposomes traditionally comprised of total polar lipids (TPL) or semi-synthetic glycerolipids of ether-linked isoprenoid phytanyl cores with varied glyco- and amino-head groups. As adjuvants, they induce robust, long-lasting humoral and cell-mediated immune responses and enhance protection in murine models of infectious disease and cancer. Traditional total polar lipid (TPL) archaeosome formulations are relatively complex and first generation semi-synthetic archaeosomes involve many synthetic steps to arrive at the final desired glycolipid composition. We have developed a novel archaeosome formulation comprising a sulfated disaccharide group covalently linked to the free sn-1 hydroxyl backbone of an archaeal core lipid (sulfated S-lactosylarchaeol, SLA) that can be more readily synthesized yet retains strong immunostimulatory activity for induction of cell-mediated immunity following systemic immunization. Herein, we have evaluated the immunostimulatory effects of SLA archaeosomes when used as adjuvant with ovalbumin (OVA) and hepatitis B surface antigen (HBsAg) and compared this to various other adjuvants including TLR3/4/9 agonists, oil-in-water and water-in-oil emulsions and aluminum hydroxide. Overall, we found that semi-synthetic sulfated glycolipid archaeosomes induce strong Ag-specific IgG titers and CD8 T cells to both antigens. In addition, they induce the expression of a number of cytokines/chemokines including IL-6, G-CSF, KC & MIP-2. SLA archaeosome formulations demonstrated strong adjuvant activity, superior to many of the other tested adjuvants.

Response to hepatitis B vaccination in patients with inflammatory bowel disease: a prospective observational study in Korea

Background/Aims

Testing for hepatitis B virus (HBV) serologic markers and appropriate vaccination are required in the management of inflammatory bowel disease (IBD) patients. We evaluated immunogenicity for HBV in IBD patients and the response to the HBV vaccination.

Methods

From May 2014 to August 2016, patients diagnosed with IBD were prospectively included and evaluated for antibody to hepatitis B surface antigen, antibody to hepatitis B core antigen, and antibody to hepatitis B surface antigen. Among the 73 patients who were confirmed with nonimmunity to HBV, 44 patients who had completed the 3-dose HBV vaccination series received a single booster vaccination, while 29 patients who had not completed the vaccinations series or were unsure of receiving the vaccination received a full vaccination series.

Results

An optimal response was obtained in 70.5% of the patients in the booster group, and 89.7% of the patients in the full vaccination group. Age younger than 26 years (odds ratio [OR], 6.01; 95% confidence interval [CI], 1.15–31.32; P=0.033) and a complete previous vaccination series (OR, 0.15; 95% CI, 0.03–0.80; P=0.026) were associated with optimal vaccine response. Previous complete vaccination series (OR, 0.11; 95% CI, 0.02–0.73; P=0.022) was the only predictive factor for lower compliance.

Conclusions

The response to the HBV vaccination was lower in patients older than 26 years and for those patients with a complete vaccination history. Since patients with a complete vaccination history also had poor compliance, serum HBV-titers should be checked more thoroughly, and a full vaccination series should be administered in cases when there is a negative response to the booster vaccination.

Correlates of GLA family adjuvants' activities

Lipopolysaccharide (LPS) is a well-defined agonist of Toll-like receptor (TLR) 4 that activates innate immune responses and influences the development of the adaptive response during infection with Gram-negative bacteria. Many years ago, Dr. Edgar Ribi separated the adjuvant activity of LPS from its toxic effects, an effort that led to the development of monophosphoryl lipid A (MPL). MPL, derived from Salmonella minnesota R595, has progressed through clinical development and is now used in various product-enabling formulations to support the generation of antigen-specific responses in several commercial and preclinical vaccines. We have generated several synthetic lipid A molecules, foremost glucopyranosyl lipid adjuvant (GLA) and second-generation lipid adjuvant (SLA), and have advanced these to clinical trial for various indications. In this review we summarize the potential and current positioning of TLR4-based adjuvant formulations in approved and emerging vaccines.

HCV-associated exosomes promote myeloid-derived suppressor cell expansion via inhibiting miR-124 to regulate T follicular cell differentiation and function

Virus-infected cells can regulate non-permissive bystander cells, but the precise mechanisms remain incompletely understood. Here we report that this process can be mediated by transfer of viral RNA-loaded exosomes shed from infected cells to myeloid-derived suppressor cells (MDSCs), which in turn regulate the differentiation and function of T cells during viral infection. Specifically, we demonstrated that patients with chronic hepatitis C virus (HCV) infection exhibited significant increases in T follicular regulatory (TFR) cells and decreases in T follicular helper (TFH) cells. These MDSC-mediated T-cell dysregulations resulted in an increased ratio of TFR/TFH and IL-10 production in peripheral blood. Specifically, co-culture of MDSCs derived from HCV patients with healthy peripheral blood mononuclear cells (PBMCs) induced expansion of TFR, whereas depletion of MDSCs from PBMCs of HCV patients reduced the increases in TFR frequency and IL-10 production, and promoted the differentiation of IFN-γ-producing TFH cells. Importantly, we found that exosomes isolated from the plasma of HCV patients and supernatant of HCV-infected hepatocytes could drive monocytic myeloid cell differentiation into MDSCs. These exosomes were enriched in tetraspanins, such as CD63 and CD81, and contained HCV RNA, but exosomes isolated from patients with antiviral treatment contained no HCV RNA and could not induce MDSC differentiation. Notably, these HCV RNA-containing exosomes (HCV-Exo) were sufficient to induce MDSCs. Furthermore, incubation of healthy myeloid cells with these HCV-Exo inhibited the expression of miR-124, whereas reconstitution of PBMCs with miR-124 abolished the effects of HCV-Exo on MDSC induction. Taken together, these results indicate that HCV-associated exosomes can transfer immunomodulatory viral RNA from infected cells to neighboring immune cells and trigger MDSC expansion, which subsequently promotes TFR differentiation and inhibits TFH function. This study reveals a previously unrecognized path that represents a novel mechanism of immune dysregulation during chronic viral infection.

Improved CD4 T cell profile in HIV-infected subjects on maraviroc-containing therapy is associated with better responsiveness to HBV vaccination

Background

Maraviroc-containing combined antiretroviral therapy (MVC-cART) improved the response to the hepatitis B virus (HBV) vaccine in HIV-infected subjects younger than 50 years old. We aimed here to explore the effect of this antiretroviral therapy on different immunological parameters that could account for this effect.

Methods

We analysed baseline samples of vaccinated subjects under 50 years old (n = 41). We characterized the maturational subsets and the expression of activation, senescence and prone-to-apoptosis markers on CD4 T-cells; we also quantified T-regulatory cells (Treg) and dendritic cell (DC) subsets. We used binary logistic regression to evaluate the immunological impact of MVC-cART, correlation with MVC exposure and linear regression for association with the magnitude of the HBV vaccine response.

Results

HIV-infected subjects on MVC-cART prior to vaccination showed increased recent thymic emigrants levels and reduced myeloid-DC levels. A longer exposure to MVC-cART was associated with lower frequencies of Tregs and activated and proliferating CD4 T-cells. Furthermore, the frequencies of activated and proliferating CD4 T-cells were inversely associated with the magnitude of the HBV vaccine response.

Conclusion

The beneficial effect of MVC-cART in the HBV vaccine response in subjects below 50 years old could be partially mediated by its reducing effect on the frequencies of activated and proliferating CD4 T-cells prior to vaccination.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1617-1) contains supplementary material, which is available to authorized users.

Hepatitis B virus pathogenesis: Fresh insights into hepatitis B virus RNA

Hepatitis B virus (HBV) is still a worldwide health concern. While divergent factors are involved in its pathogenesis, it is now clear that HBV RNAs, principally templates for viral proteins and viral DNAs, have diverse biological functions involved in HBV pathogenesis. These functions include viral replication, hepatic fibrosis and hepatocarcinogenesis. Depending on the sequence similarities, HBV RNAs may act as sponges for host miRNAs and may deregulate miRNA functions, possibly leading to pathological consequences. Some parts of the HBV RNA molecule may function as viral-derived miRNA, which regulates viral replication. HBV DNA can integrate into the host genomic DNA and produce novel viral-host fusion RNA, which may have pathological functions. To date, elimination of HBV-derived covalently closed circular DNA has not been achieved. However, RNA transcription silencing may be an alternative practical approach to treat HBV-induced pathogenesis. A full understanding of HBV RNA transcription and the biological functions of HBV RNA may open a new avenue for the development of novel HBV therapeutics.

Impaired Immune Response to Primary but Not to Booster Vaccination Against Hepatitis B in Older Adults

Many current vaccines are less immunogenic and less effective in elderly compared to younger adults due to age-related changes of the immune system. Most vaccines utilized in the elderly contain antigens, which the target population has had previous contact with due to previous vaccination or infection. Therefore, most studies investigating vaccine-induced immune responses in the elderly do not analyze responses to neo-antigens but rather booster responses. However, age-related differences in the immune response could differentially affect primary versus recall responses. We therefore investigated the impact of age on primary and recall antibody responses following hepatitis B vaccination in young and older adults. Focused gene expression profiling was performed before and 1 day after the vaccination in order to identify gene signatures predicting antibody responses. Young (20-40 years; n = 24) and elderly (>60 years; n = 17) healthy volunteers received either a primary series (no prior vaccination) or a single booster shot (documented primary vaccination more than 10 years ago). Antibody titers were determined at days 0, 7, and 28, as well as 6 months after the vaccination. After primary vaccination, antibody responses were lower and delayed in the elderly compared to young adults. Non-responders after the three-dose primary series were only observed in the elderly group. Maximum antibody concentrations after booster vaccination were similar in both age groups. Focused gene expression profiling identified 29 transcripts that correlated with age at baseline and clustered in a network centered around type I interferons and pro-inflammatory cytokines. In addition, smaller 8- and 6-gene signatures were identified at baseline that associated with vaccine responsiveness during primary and booster vaccination, respectively. When evaluating the kinetic changes in gene expression profiles before and after primary vaccination, a 33-gene signature, dominated by IFN-signaling, pro-inflammatory cytokines, inflammasome components, and immune cell subset markers, was uncovered that was associated with vaccine responsiveness. By contrast, no such transcripts were identified during booster vaccination. Our results document that primary differs from booster vaccination in old age, in regard to antibody responses as well as at the level of gene signatures.

Clinical Trial Registration

www.clinicaltrialsregister.eu, this trial was registered at the EU Clinical Trial Register (EU-CTR) with the EUDRACT-Nr. 2013-002589-38.

Monitoring the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children: Protective anti-HBs levels and cellular immune responses

Vaccination against hepatitis B virus (HBV) is recommended worldwide. The aim of this study was to assess the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children in the context of protective anti-HBs levels and cellular immune responses. Using a random questionnaire survey, 1695 pre-school children were recruited as research subjects during January 2015 to June 2017. Blood samples were obtained to measure HBV serological markers as well as peripheral immunocytes. The children were divided into non-, low- and hyper- responsive groups (NR, LR, and HR) based on the vaccination efficacy. Additionally, the effect of revaccination on the NR group was evaluated at 1 month after completion of the vaccination course. Among a total of 1695 children, 1591 (93.86%) were infants who were followed while undergoing their primary course of hepatitis B vaccination at the 0-1-6 month schedule, and 1249 (79.30%) of them developed antibodies against HBsAg (anti-HBs) titers greater than 10 IU/L. The results of immunocyte studies indicated that the CD8⁺ T cells, CD4⁺CD45RO⁺ T cells, CD8⁺CD45RA⁺ T cells, and T follicular helper (Tfh) cells increased significantly in NR compared with HR. However, lymphocytes, CD4⁺ T cells, and CD4⁺CD45RA⁺ T cells in NR were lower than that in HR. 96 of the non-response cases showed seroprotection after revaccination among 103 cases. Therefore, most of the preschool children who received hepatitis B vaccine in infancy achieved significant seroprotection. Seroconversion rates of individuals revaccinated after initial vaccination failure were significantly higher than those after primary vaccination. Different vaccination efficacy groups showed significant changes in circulating immunocytes, which might be a factor affecting the recombinant HBV vaccine's immune effectiveness.

Vaccines for the elderly: current use and future challenges

Age-related changes of the immune system contribute to increased incidence and severity of infections in the elderly. Vaccination is the most effective measure to prevent infections and vaccination recommendations in most countries include specific guidelines for the elderly. Vaccination against influenza and Streptococcus pneumoniae is usually recommended for persons with underlying diseases and for the elderly with heterogeneous age limits between ≥ 50 years and ≥ 65 years. Some countries also recommend vaccination against herpes zoster. Several vaccines are recommended for all adults, such as regular booster shots against tetanus/diphtheria/pertussis/polio, or for specific groups, e.g. vaccination against tick-borne encephalitis in endemic areas or travel vaccines. These are also relevant for the elderly. Most currently used vaccines are less immunogenic and effective in the elderly compared to younger adults. Potential strategies to improve their immunogenicity include higher antigen dose, alternative routes of administration, and the use of adjuvants, which were all implemented for influenza vaccines, and induce moderately higher antibody concentrations. Research on universal vaccines against influenza and S. pneumoniae is ongoing in order to overcome the limitations of the current strain-specific vaccines. Respiratory syncytial virus causes significant morbidity in the elderly. Novel vaccines against this and other pathogens, for instance bacterial nosocomial infections, have tremendous potential impact on health in old age and are intensively studied by many academic and commercial organizations. In addition to novel vaccine developments, it is crucial to increase awareness for the importance of vaccination beyond the pediatric setting, as vaccination coverage is still far from optimal for the older population.

Immunogenicity of a two-dose investigational hepatitis B vaccine, HBsAg-1018, using a toll-like receptor 9 agonist adjuvant compared with a licensed hepatitis B vaccine in adults

BACKGROUND

Hepatitis B virus infection remains an important public health problem in the United States. Currently approved alum-adjuvanted vaccines require three doses and have reduced immunogenicity in adults, particularly in those who have diabetes mellitus, or are older, male, obese, or who smoke.

METHODS

Phase 3 observer-blinded, randomized (2:1 HBsAg-1018 [HEPLISAV-B™]:HBsAg-Eng [Engerix-B®]), active-controlled trial in adults 18-70 years of age. HBsAg-1018 was administered intramuscularly at weeks 0 and 4 and placebo at week 24 and HBsAg-Eng at weeks 0, 4, and 24. The primary immunogenicity endpoint assessed the noninferiority of the seroprotection rate at week 28 in participants with type 2 diabetes mellitus. Secondary endpoints included seroprotection rates in the total trial population and by age, sex, body mass index, and smoking status.

RESULTS

Among 8374 participants randomized, 961 participants in the per-protocol population had type 2 diabetes mellitus. In diabetes participants, the seroprotection rate in the HBsAg-1018 group at week 28 was 90.0%, compared with 65.1% in the HBsAg-Eng group, with a difference of 24.9% (95% CI: 19.3%, 30.7%), which met the prospectively-defined criteria for noninferiority and statistical significance. In the total study per-protocol population (N = 6826) and each pre-specified subpopulation, the seroprotection rate in the HBsAg-1018 group was statistically significantly higher than in the HBsAg-Eng group.

CONCLUSION

Two doses of HBsAg-1018, administered over 4 weeks, induced significantly higher seroprotection rates than three doses of HBsAg-Eng, given over 24 weeks, in adults with factors known to reduce the immune response to hepatitis B vaccines as well as in those without those factors. With fewer doses in a shorter time, and greater immunogenicity, HBsAg-1018 has the potential to significantly improve protection against hepatitis B in adults at risk for hepatitis B infection. Trial Registration clinicaltrials.gov Identifier: NCT02117934.

Robust Antibody and Cytokine Response to Hepatitis B Vaccine Among Not-in-Treatment Patients With Chronic Hepatitis C: An Open-Label Control Study in China

Background

Hepatitis B vaccine is an effective measure to prevent hepatitis B virus infection. Whether chronic hepatitis C virus (HCV) infection decreases humoral and cell-mediated immunity responses to hepatitis B vaccination is still controversial.

Methods

Patients with chronic HCV infection who were not in treatment and healthy controls, matched at a 1:2 ratio for community, sex, and age (within 5 years), were identified from a community-based screening. All participants received 3 doses of hepatitis B vaccine. Antibody to hepatitis B surface antigen was tested 1 month after the third vaccine dose and was compared between 2 groups. Spot-forming cells (SFCs) of interferon γ and interleukin 2, 4, 5, and 6 were counted by means of enzyme-linked immunospot, and SFC counts were compared between the 2 groups.

Results

The rates of nonresponse and low, normal, and high response were 3.80%, 10.13%, 45.57%, and 40.50% respectively, in the HCV group, and the corresponding rates in the healthy control group were 1.26%, 10.13%, 39.24%, and 49.37% (all P > .05). There were no significant differences in SFC counts between the 2 groups for interferon γ or interleukin 2, 4, or 5 (all P > .05).

Conclusions

This study provided preliminary evidence of the good immunogenicity and safety of hepatitis B vaccination among patients in China with chronic hepatitis C who are not in treatment.

Clinical Trials Registration

NCT 02898922.

The Immune Response of Vaccination Against Hepatitis B virus in Iranian Patients Undergoing Chemotherapy

Introduction:

Hepatitis B virus (HBV) infection and its complications are major public health problems. As it is hard to treat and control the chronic state, control of disease depends on the prevention especially by vaccination. There is an impaired immune response to vaccinations including HBV in patients with some malignancies. The aim of this study is to assess the response rate of patients undergoing chemotherapy to HBV vaccination.

Materials and Methods:

All patients from two hematology/oncology clinics in Isfahan, Iran with the history of at least 1 month chemotherapy who had the inclusion criteria were enrolled in a case control study. Also a sex- and age-matched control group from healthy population was selected. They were vaccinated in a schedule of 0, 1, and 6 months and were examined for antibody titers 1 month after the last dose. The titers more than 10 mIU/ml were determined as positive response to vaccination.

Results:

In this study, 50 patients and 50 healthy subjects were enrolled. The two groups were age and sex matched (P > 0.05). Frequency of negative responses to HBV vaccination in case and control groups were 9 (18%) and 1 (2%), respectively (OR = 10.75, CI = 1.30–88.47, P = 0.027). Of 50 patients, 54%, 12%, 22%, and 12% had breast cancer, lymphoma, gastrointestinal, and genitourinary cancers, respectively, and frequency of negative responses were 3 (11%), 1 (16%), 4 (36.4%), and 1 (16%), respectively (P = 0.167).

Conclusion:

According to our results, malignancy and chemotherapy will have an important effect on the immune system and cause negative response to HBV vaccination. Our results revealed the importance of passive immunity and screening for HBV infection in patients undergoing chemotherapy. Also more studies for better vaccination schedules in this group of patients are recommended.

The in vitro MIMIC® platform reflects age-associated changes in immunological responses after influenza vaccination

Increasing research and development costs coupled with growing concerns over healthcare expenditures necessitate the generation of pre-clinical testing models better able to predict the efficacy of vaccines, drugs and biologics. An ideal system for evaluating vaccine immunogenicity will not only be reliable but also physiologically relevant, able to be influenced by immunomodulatory characteristics such as age or previous exposure to pathogens. We have previously described a fully autologous human cell-based MIMIC® (Modular IMmune In vitro Construct) platform which enables the evaluation of innate and adaptive immunity in vitro, including naïve and recall responses. Here, we establish the ability of this module to display reduced antibody production and T cell activation upon in vitro influenza vaccination of cells from elderly adults. In the MIMIC® system, we observe a 2.7-4.2-fold reduction in strain-specific IgG production to seasonal trivalent influenza vaccine (TIV) in the elderly when compared to adults, as well as an age-dependent decline in the generation of functional antibodies. A parallel decline in IgG production with increasing age was detected via short-term ex vivo stimulation of B cells after in vivo TIV vaccination in the same cohort. Using MIMIC®, we also detect a reduction in the number but not proportion of TIV-specific multifunctional CD154⁺IFNγ⁺IL-2⁺TNFα⁺ CD4⁺ T cells in elderly adults. Inefficient induction of multifunctional helper T cells with TIV stimulation in MIMIC® despite a normalized number of initial CD4⁺ T cells suggests a possible mechanism for an impaired anti-TIV IgG response in elderly adults. The ability of the MIMIC® system to recapitulate differential age-associated responses in vitro provides a dynamic platform for the testing of vaccine candidates and vaccine enhancement strategies in a fully human model including the ability to interrogate specific populations, such as elderly adults.

Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations

Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years) and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity) may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb) responses to vaccinia waned after 5–10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT) of 250 to baseline (<20) after 10–20 years post vaccination. This contrasted with a comparator group of adults, ages 35–49, who were vaccinated with Dryvax® as children. In the childhood vaccinees, titers persisted for >30 years with a GMT of 210 (range 112–3234). This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program.