Characteristics of immune memory 10-15 years after primary hepatitis B vaccination

Recurrence and influencing factors of hepatitis B surface antigen seroclearance induced by peginterferon alpha-based regimens

BACKGROUND

The long-term stability of hepatitis B surface antigen (HBsAg) seroclearance following peginterferon alpha (peg-IFN-α)-based therapy has not been extensively studied, leaving the full potential and limitations of this strategy unclear.

AIM

To assess HBsAg recurrence after seroclearance achieved by peg-IFN-α regimens.

METHODS

This prospective, multicenter, observational study was conducted from November 2015 to June 2021 at three Chinese hospitals: The Second Affiliated Hospital of Xi'an Jiaotong University, Ankang Central Hospital, and The Affiliated Hospital of Yan'an University. Participants who achieved HBsAg seroclearance following peg-IFN-α-based treatments were monitored every 4-12 weeks post-treatment for hepatitis B virus (HBV) markers, HBV DNA, and liver function. The primary outcome was HBV recurrence, defined as the reemergence of HBsAg, HBV DNA, or both, at least twice within 4-8 weeks of follow-up.

RESULTS

In total, 121 patients who achieved HBsAg seroclearance were enrolled. After a median follow-up of 84.0 (48.0, 132.0) weeks, four subjects were lost to follow-up. HBsAg recurrence was detected in 16 patients. The cumulative HBsAg recurrence rate in the intention-to-treat population was 15.2%. Multivariate logistic regression analysis demonstrated that consolidation time < 12 weeks [odds ratio (OR) = 28.044, 95%CI: 4.525-173.791] and hepatitis B surface antibody disappearance during follow-up (OR = 46.445, 95%CI: 2.571-838.957) were strong predictors of HBsAg recurrence. HBV DNA positivity and decompensation of liver cirrhosis and hepatocellular carcinoma were not observed.

CONCLUSION

HBsAg seroclearance following peg-IFN-α treatment was durable over 84 weeks of follow-up with a cumulative recurrence rate of 15.2%.

HBV Antigen-Guided Switching Strategy From Nucleos(t)ide Analogue to Interferon: Avoid Virologic Breakthrough and Improve Functional Cure

Little is known for factors associated with virologic breakthrough (VBT) after switching from nucleos(t)ide analogue (NA) to pegylated interferon alpha (Peg-IFN-α) for patients with chronic hepatitis B (CHB). Eighty patients who received 48-week Peg-IFN-ɑ and NA combination therapy followed by Peg-IFN-ɑ monotherapy for additional 48 weeks were included in this study. HBV-related markers including HBV DNA, HBsAg, HBcrAg, HBeAg, cccDNA, and immunological biomarkers were dynamically evaluated. Twelve (15.0%) patients experienced VBT after switching to Peg-IFN-ɑ and exhibited significantly lower rates of HBsAg loss after therapy completion (0% vs. 35.3%, p = 0.014). The patients with HBcrAg≥ 5 log10U/mL and HBsAg≥ 100 IU/mL had the highest risk of VBT and failed to achieve subsequent HBsAg clearance. Intrahepatic cccDNA level was significantly higher in patients with HBcrAg≥ 5 log10U/mL than those with HBcrAg< 5 log10U/mL. Notably, in contrast to patients with HBcrAg< 5 log10U/mL or with HBsAg< 100 IU/mL who had obviously restored HBV-specific CD8+T cell, Tfh or B cell responses before NA cessation, those with HBcrAg≥ 5 log10U/mL or with HBsAg≥ 100 IU/mL exhibited lackluster immunities before NA cessation and notable diminished immune responses thereafter. Monitoring HBcrAg and HBsAg levels, which correlated with poor immune responses during sequential Peg-IFN-ɑ strategy, may help to avoid VBT and improve functional cure of CHB.

The potential effect of HBV vaccination on off-treatment HBsAg reversion after interferon-induced HBsAg clearance

Off-treatment HBsAg reversion occurs in a considerable number of chronic hepatitis B(CHB) patients after IFN(interferon)-induced HBsAg clearance. HBV vaccination protects the general population against HBV infection. However, it remains unclear whether HBV vaccination could prevent off-treatment HBsAg reversion in CHB patients with HBsAg clearance. CHB patients (n = 199) with HBsAg clearance were included in the current study, comprising spontaneous HBsAg clearance group (n = 51), NA (nucleoside/nucleotide analogues)-induced group (n = 36) and IFN-induced group (n = 112). Log-rank test was performed to compare the cumulative incidences of HBsAg reversion between groups. Cox regression model was used to identify the factors associated with off-treatment HBsAg reversion. The 5-year cumulative incidence of HBsAg reversion in IFN-induced group was significantly higher than that in NA-induced group or spontaneous group (27.6% vs. 3.3% vs. 8.1%, both p < .05). In IFN-induced group, 66.7% of CHB patients received HBV vaccination. The cumulative incidence of HBsAg reversion in individuals with strong responses to HBV vaccination (HBsAb level >100mIU/ml) was significantly lower than that in those with weak responses to HBV vaccination (HBsAb level ≤100mIU/ml) or without HBV vaccination in IFN-induced group (7.7% vs. 58.5% vs. 31.9%, both p < .05). Multivariate Cox regression analysis confirmed strong responses to HBV vaccination were independently associated with a lower cumulative incidence of HBsAg reversion after IFN-induced HBsAg clearance (HR = 0.246, 95%CI: 0.066-0.907, p = .035). HBV vaccination has potential to prevent off-treatment HBsAg reversion in CHB patients after IFN-induced HBsAg clearance via a sufficiently high level of HBsAb, helping clinicians optimize the clinical management of such patients.

Frequency of B-Cell Subpopulations in Low Responders in Comparison with High Responders to Hepatitis B Vaccine Among Health Care Workers

Vaccination is the most effective way to prevent Hepatitis B (HB) infection. The goal of vaccination is to induce immunological memory. Hence, determining the frequency of memory B-cell (MBC) subsets is an important indicator of vaccine efficacy. This study aimed to evaluate the frequency of different B-cell subpopulations and the expression of PD-1 on B-cell subsets in low responders (LR) and high responders (HR) to HB vaccine. According to our findings, the expression level of PD-1 was significantly higher on atypical MBC (atMBC) than that of naive B cell and classical MBC (cMBC) in LR and HR groups. Moreover, cMBCs had a significant higher PD-1 expression than naive B cells in LR group. No significant differences were found in the frequency of various B-cell subpopulations and the expression level of PD-1 on B-cell subsets between LR and HR groups. We observed a negative correlation between age and HBsAb titer and a positive correlation between age and PD-1 expression level on cMBC in LR group. It can be concluded that inadequate specific memory B-cell response, rather than total memory B-cell deficiency, may be implicated in low responsive rate to HB vaccine in healthy individuals.

Effect of Anti-HBs on Mortality Among Resolved HBV Infection: a Population-Based Prospective Cohort Study

INTRODUCTION

Surveillance programs after hepatitis B surface antigen (HBsAg) loss are not yet well established, and the role of hepatitis B surface antibodies (anti-HBs) remains controversial. We aimed to evaluate the risk factors for increased mortality and the association between anti-HBs and all-cause and cause-specific mortality in a representative US (United States) population of patients with resolved HBV (Hepatitis B virus) infections.

METHODS

Data were taken from the US National Health and Nutrition Examination Survey (NHANES) 1999-2018. A total of 3455 US adults with resolved HBV infection [defined as hepatitis B surface antigen (HBsAg) negative/anti-hepatitis B core antigen (anti-HBc) positive] were enrolled in this study. The primary outcome measures were all-cause and cause-specific mortality from baseline until 31 December 2019.

RESULTS

During a mean follow-up of 10.3 years, 741 deaths occurred. Age, race, marital status, smoking status, physical activity level, and presence of cirrhosis, diabetes, cardiovascular diseases, chronic obstructive pulmonary diseases, cancer, and anti-HBs were significant factors for increased mortality, and a nomogram tool was developed and validated for the risk stratification of mortality. Compared with participants who were anti-HBs positive, those who were anti-HBs negative had a 23% (hazard ratio 1.23, 95% CI 1.02-1.46) higher risk of all-cause mortality in NHANES 1999-2018. For cause-specific mortality, the fully adjusted hazard ratios of participants who were anti-HBs negative were 0.71 (95% CI 0.48-1.06) for heart disease, 1.44 (95% CI 1.01-2.05) for cancer, and 1.44 (95% CI 1.13-1.83) for other conditions, compared to those of participants who were anti-HBs positive.

CONCLUSIONS

Among US adults with resolved HBV infections, anti-HBs-negative status was associated with an increased risk of death from all causes and cancer, implying that the role of anti-HBs in resolved HBV infection should not be ignored. On the public health level, more rigorous surveillance was needed for populations of individuals who were isolated anti-HBc positive.

End-of-treatment HBcrAg and HBsAb levels identify durable functional cure after Peg-IFN-based therapy in patients with CHB

BACKGROUND & AIMS

Functional cure can be sustained in a proportion of patients with chronic hepatitis B (CHB) who lose hepatitis B surface antigen (HBsAg) after pegylated interferon alpha (Peg-IFN-ɑ)-based treatment. In this study, we aimed to identify biomarkers associated with a durable functional cure and to dissect potential immunological mechanisms.

METHODS

Of 257 nucleos(t)ide analogue-suppressed patients with CHB in the ANCHOR study, 80 patients randomly assigned to 96-week Peg-IFN-α-based therapy with 24-week off-treatment follow-up were included in this parallel study. Virologic and immunological biomarkers were examined dynamically. A response was defined as HBsAg loss or hepatitis B surface antibody (HBsAb) appearance at the end of treatment (EOT). Sustained response (SR) or durable functional cure was defined as sustained HBsAg loss with or without the appearance of HBsAb at the end of follow-up (EOF).

RESULTS

Thirty-six (45.0%) out of 80 patients achieved a response at EOT; 58.3% (21/36) of responders maintained SR at EOF. Quantitative hepatitis B core-related antigen (qHBcrAg) and HBsAb at EOT were associated with SR, with AUROCs of 0.697 (0.512-0.882, p = 0.047) and 0.744 (0.573-0.915, p = 0.013), respectively. A combination of HBcrAg <4 log₁₀U/ml and HBsAb >2 log₁₀IU/L at EOT had a positive predictive value of 100% for SR with an AUROC of 0.822 (0.684-0.961, p = 0.001). These patients showed maintained proportions of HBV envelope-specific CD8⁺T and B cells, a markedly increased proportion of T follicular helper cells after Peg-IFN-ɑ discontinuation, and significantly higher proportions of HBV polymerase-specific CD8⁺T and CD86⁺CD19⁺B cells at EOF.

CONCLUSIONS

Lower HBcrAg and higher HBsAb levels at EOT were associated with sustained cellular and humoral immune responses. They can be used to identify patients likely to achieve durable functional cure post Peg-IFN-based therapy.

GOV IDENTIFIER

NCT02327416 LAY SUMMARY: Functional cure can be sustained in a proportion of patients with chronic hepatitis B after pegylated interferon alpha-based treatment. However, predicting who will achieve durable functional cure remains challenging. Herein, we show that low levels of hepatitis B core-related antigen and higher levels of hepatitis B surface antibodies at the end of treatment are linked to immunological responses and are associated with durable functional cure.

Hepatitis B Vaccination Induces Mucosal Antibody Responses in the Female Genital Tract, Indicating Potential Mechanisms of Protection Against Infection

Vaccines against hepatitis B virus confer effective protection. Enzyme-linked immunosorbent assay was developed to test for specific antibodies in female genital tract secretions. Anti-hepatitis B IgG and IgA were detected in the cervicovaginal secretions of women after hepatitis B vaccination, indicating a potential genital tract role for neutralizing antibodies against sexually transmitted hepatitis B virus.

Lasting benefit of infant hepatitis B vaccination in adolescents in the Lao People's Democratic Republic

OBJECTIVES

Hepatitis B is endemic in Lao PDR with 8-10% of the adult population being chronically infected. We investigated the impact of hepatitis B vaccination on infection in adolescents born shortly before and after the introduction of the vaccine in 2001.

METHODS

779 students from Vientiane Capital and Bolikhamxay province were tested for HBV markers by ELISA. Socio-demographic information was collected with a standardized questionnaire. Predictors/risk factors for seroprotection or exposure to hepatitis B infection were assessed by bivariate and multivariable analyses.

RESULTS

The prevalence of a serological vaccination profile increased significantly after the introduction of the vaccine (13.2%-21.9%, p < 0.05, in Vientiane; 3.0%-19.7%, p < 0.001, in Bolikhamxay), which translated into at least a 2-times lower prevalence of past infection. In logistic regression, older students in Bolikhamxay were less likely to be vaccinated and more likely to have been infected by HBV in the past.

CONCLUSION

Even though this study documented a sizable and lasting reduction in past hepatitis B infections in adolescents born after the introduction of infant hepatitis B vaccination, the overall levels of protective anti-HBs were low and warrant at least the introduction of a booster for adolescents. Furthermore, we suggest improving the coverage of the hepatitis B birth dose.

Persistence of HBsAg-specific antibodies and immune memory two to three decades after hepatitis B vaccination in adults

The duration of protection after hepatitis B vaccination is not exactly known. This phase IV study evaluated antibody persistence and immune memory 20-30 years after adult immunization with recombinant hepatitis B vaccine (HBsAg vaccine, Engerix-B) in routine clinical practice. Men and women 40-60 years old, with documented evidence of vaccination with three or four HBsAg vaccine doses 20-30 years earlier and without subsequent booster, were enrolled and received HBsAg vaccine as challenge dose. HBsAg-specific antibodies (anti-HBs) and frequencies of HBsAg-specific circulating memory B cells and CD4+ T cells expressing combinations of activation markers (CD40L, IL2, IFNγ, TNFα) were measured prechallenge, 7 and 30 days postchallenge. Of 101 participants in the according-to-protocol cohort for immunogenicity, 90.1% had anti-HBs concentrations ≥ 10 mIU/mL prechallenge administration; 84.2% and 100% mounted an anamnestic response 7 and 30 days postchallenge, respectively. HBsAg-specific memory B and CD4+ T cells expressing at least two activation markers were low prechallenge and increased markedly postchallenge. These results suggest sustained immune memory and long-term protection 20-30 years after a complete primary HBsAg vaccination course during adulthood, in line with current recommendations that a booster is not needed in fully vaccinated immunocompetent adults.

Anti-Hepatitis B Antibody Levels In Immunized Medical Students: Are They At Risk?

INTRODUCTION

Medical students have an occupational risk for hepatitis B (HB). This study sought to determine anti-HBs and anti-HBc IgG levels in vaccinated students, check their seroconversion, and correlate this with vaccination.

METHODS

One hundred and forty-three students' blood samples and their vaccination schedules were analyzed.

RESULTS

65.7% were positive for anti-HBs; however, anti-HBs was absent in 34.3%. Only two samples were positive for anti-HBc IgG.

CONCLUSIONS

More than 30% of students did not have minimum protective levels. Comparing HBV vaccination and anti-HBs reactivity, the majority of reactive individuals received their last dose within the past 16 years.

Antibody response after hepatitis B vaccine boost mapped with peptide-phage display

Recombinant hepatitis B virus vaccines confer protection by eliciting specific antibodies against the hepatitis B surface antigen (HBsAg), known as anti-HBs. However, the performance of rapid anti-HBs diagnostic tests generates concerns regarding consistency. Novel indicators of protection might be developed by monitoring changes in targeted HBsAg-epitope profile after vaccination. In this work, we test the feasibility of our peptide-phage display platform in identifying B-cell epitopes targeted at different time-points after hepatitis B vaccination. We combined this platform with a unique approach for in silico analysis of enriched sequences. Serum samples collected from one single patient who had two boosting immunizations against hepatitis B virus were used in two-rounds of selection experiments. Five epitope candidates from HBsAg were identified in silico; most of them were previously reported in the literature. Our results suggest that the number of recognized HBsAg epitopes is related to the decrease of anti-HBs over time.

Diverse immune responses to HBV surface epitope variants after vaccine booster in adolescents immunized in infancy

OBJECTIVES

We aimed to investigate immunity against hepatitis B surface antigen (HBsAg) mutants before and after boosters in adolescents who had lost antibodies against HBsAg (anti-HBs) despite neonatal vaccination.

METHODS

We recruited 142 participants from 15 to 21 years old who had received complete vaccination in infancy but became anti-HBs-negative. Cellular immunity to HBsAg and T-cell epitope variants was assessed before and after boosters. Antibody affinity to variants was assessed after boosters.

RESULTS

After one dose of booster, 12 out of 140 (8.6%) participants remained anti-HBs-negative. Anti-HBs titres were higher in those participants <17 (geometric mean, 337.9 ± 10.9 vs. 157.4 ± 16.6 mIU/mL, p = 0.012). Before the booster, HBsAg-specific cell proliferation was present in 58 out of 64 (90.6%) participants. The proliferation response rates to T-cell epitopes were 37.8% and 72.6% (p < 0.001) before and after the booster, respectively. The stimulation index improved from 1.25 ± 1.70 to 2.53 ± 2.32 (p < 0.001) for various T-cell epitopes. HBsAg-specific interleukin (IL)-5- and interferon (IFN)-γ-secreting T-cells were enhanced (45 ± 10 and 50 ± 4 to 420 ± 328 and 355 ± 424 spot-forming cells/10⁶ cells, respectively, p < 0.001). IFN-γ-secreting T cells to epitope 16-33 containing R24K and the antibody affinity to sG145R were still significantly lower than to the wild type.

CONCLUSIONS

In immunized adolescents who lost anti-HBs, around 10% also lost immune memory. Cellular immunity to some T-cell epitope variants improved after the booster. Antibody affinity to sG145R and the IFN-γ-secreting cell response to some epitope 16-33 variants were still impaired even after booster administration.

Divergent Primary Immune Responses Induced by Human Immunodeficiency Virus-1 gp120 and Hepatitis B Surface Antigen Determine Antibody Recall Responses

The development of a vaccine based on human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) that elicits potent protective antibodies against infection has been challenging. Recently, we compared the antibody production patterns of HIV-1 Env gp120 and hepatitis B virus surface antigen (HBsAg) to provide insights into how we may improve the protective efficacy of Env-based immunogens. Our previous study showed that HIV Env and HBsAg display different mechanisms of antibody elicitation and that T cells facilitate the responses to repeated immunizations. Here, to elucidate the detailed roles of primary immunization in immune memory response formation and antibody production, we immunized C57BL/6 mice with each antigen and evaluated the development of T follicular helper (Tfh) cells, germinal centers, and the memory responses involved in prime and boost immunizations. We found that after prime immunization, compared with HBsAg, gp120 induced higher frequencies of Tfh cells and programmed death (PD)-1⁺ T cells, greater major histocompatibility complex II expression on B cells, comparable activated B cells, but weaker germinal center (GC) reactions and memory B cell responses in the draining lymph nodes, accompanied by slower antibody recall responses and poor immune memory responses. The above results suggested that more PD-1⁺ T cells arising in primary immunization may serve as major contributors to the slow antibody recall response elicited by HIV-1 Env.

Use of ELISpot assay to study HBs-specific B cell responses in vaccinated and HBV infected humans

Hepatitis B surface antibody (HBsAb) plays a critical role in protecting against infection of hepatitis B virus (HBV) and were extensively studied in literature. At the same time, the status of hepatitis B surface antigen (HBs)-specific B cells in both vaccinated and HBV infected people received limited attention. In the current study, we adopted a highly specific B-cell Enzyme Linked ImmunoSpot (ELISpot) assay to analyze HBs-specific B cells in various clinical settings: healthy individuals with the history of HBV vaccination before and after receiving an extra HBV vaccine boost, people chronically infected with HBV (CHB) in various clinical stages, with or without a particular type anti-viral treatment, or whether receiving a dose of HBV vaccine. In all of these cases, B-cell ELISpot assay was used effectively in enumerating the frequency of HBs-specific B cells. While the focus of the current report was to establish the utility of this assay for HBV research, a number of interesting observations were made in this pilot study based on the profiles and dynamics of HBs-specific B cells in various conditions. Such information is useful to guide the future work in designing novel therapeutic strategies against CHB.

A Prospective Study of Humoral and Cellular Immune Responses to Hepatitis B Vaccination in Habitual Marijuana Smokers

Exposure to Δ⁹-tetrahydrocannabinol (THC) in vitro and in animal models can significantly impair the differentiation, activation and function of dendritic cells, T cells and B cells. However, studies directly assessing the impact of marijuana smoking on human immunity are lacking. A prospective study of immune responses to a standard hepatitis B vaccination was therefore carried out in a matched cohort of 9 marijuana smokers (MS) and 9 nonsmokers (NS). In addition to their regular marijuana use, MS smoked four marijuana cigarettes in a monitored setting on the day of each vaccination. Blood samples were collected over time to assess the development of hepatitis B-specific immunity. The majority of subjects from both the NS (8) and MS (6) groups developed positive hepatitis B surface antibody titers (>10 IU/L) and of these 6 NS and 5 MS were classified as high antibody (good) responders (>100 IU/L). The development of a good response correlated with the presence of hepatitis B-specific T cell proliferation and cytokine production, resulting in a clear distinction regarding the immune status of good responders versus non-responders. However, even though there were slighter more non-responders in the MS cohort, there were no significant differences between MS and NS with respect to peripheral blood cell phenotypes or vaccination-related changes in hepatitis B responses. While a larger cohort may be required to rule out a small suppressive effect, our findings do not suggest that habitual marijuana smoking exerts a major impact on the development of systemic immunity to hepatitis B vaccination.

Will Infant Hepatitis B Vaccination Protect Into Adulthood?: Extended Canadian Experience After a 2-, 4- and 6-month Immunization Schedule

BACKGROUND

Hepatitis B virus (HBV) vaccination programs generally target infants to prevent chronic HBV infection and/or preadolescents to reduce transmission in adulthood. To assess whether infant HBV immunization can potentially accomplish both objectives, we measured residual immunity 10-16 years after vaccination in Canadian children.

METHODS

A prospective, parallel group, single center study enrolled adolescents given HBV vaccine at 2, 4 and 6 months of age. Exclusion criteria included prior HBV infection and additional vaccinations. At follow-up anti-HBs testing, participants were 10-11 or 15-16 years old; those with <12 mIU/mL anti-HBs by the assay used were challenged with HBV vaccine to assess immune memory-based responsiveness.

RESULTS

A total of 137 tested participants were 10-11 and 213 were 15-16 years old, respectively; none had evidence of prior HBV infection. At baseline, 78% of younger and 64% of older participants had <12 mIU/mL anti-HBs (P = 0.006) and were challenged with vaccine: 103/106 (97.2%) younger and 123/135 (91.1%) older participants developed ≥12 mIU/mL anti-HBs (P = 0.06), with geometric mean antibody concentration of 590 (95% confidence interval: 473-737) and 319 mIU/mL (95% confidence interval: 229-445; P = 0.004), respectively. Immune memory loss may have occurred in 3 younger (2.2%) and 12 older children (5.6%; P = 0.06) who were nonresponsive to first but not second vaccine challenge.

CONCLUSIONS

After HBV vaccination at 2, 4 and 6 months of age, most adolescents had little or no residual antibody but nearly all responded to HBV challenge, confirming immune memory persistence. However, anamnestic responses were weaker in 15- to 16-year olds and lost in some. Booster responses in 10- to 11-year olds were vigorous in comparison. Extended evaluation of protection is warranted.