The response of isolated anti-HBc positive subjects to recombinant hepatitis B vaccine

Hepatitis B virus screening in Asian immigrants: Community-based campaign to increase screening and linkage to care: A cross-sectional study

Background and Aims

Despite established screening guidelines, many Asian immigrants remain unscreened. Furthermore, those with chronic hepatitis B (CHB) are not linked to care citing multiple barriers. The objective of this study was to determine the role of our community-based hepatitis B virus (HBV) campaign on HBV screening and the success of linkage to care (LTC) efforts.

Methods

Asian immigrants from the New Jersey and New York metropolitan areas were screened for HBV from 2009 to 2019. We started to collect LTC data starting in 2015, and those found to be positive were followed up. In 2017, because of low LTC rates, nurse navigators were hired to aid in the LTC process. Those excluded from the LTC process included those who were already linked to care, declined, and/or had moved or passed away.

Results

Total of 13,566 participants were screened from 2009 to 2019, of which, the results for 13,466 were available. Of these, 372 (2.7%) were found to have positive HBV status. Approximately 49.3% were female and 50.1% were male, and the rest were of unknown gender. A total of 1191 (10.0%) participants were found to be HBV negative but required vaccination. When we started to track LTC, we found 195 participants that were eligible for LTC between 2015 and 2017 after the exclusion criteria were applied. It was found that only 33.8% were successfully linked to care in that time period. After hiring nurse navigators, we saw LTC rates increase to 85.7% in 2018 and to 89.7% in 2019.

Conclusion

HBV community screening initiatives are imperative to increase screening rates in the Asian immigrant population. We were also able to demonstrate that nurse navigators can successfully help increase LTC rates. Our HBV community screening model can address issues with barriers to care including lack of access in comparable populations.

Effectiveness of hepatitis B vaccination in chronic HCV patients after successful generic direct acting antiviral therapy: significance of isolated hepatitis B core antibodies

OBJECTIVE

Previous reports show conflicting results regarding hepatitis B virus (HBV) vaccine efficacy in Hepatitis C virus (HCV) infected individuals and in those with isolated hepatitis B core antibodies (HBcAb). We aimed to evaluate the effectiveness of HBV vaccine and identify possible factors that may contribute to hyporesponsivness in HCV-treated patients, including those with isolated HBcAb.

METHODS

We conducted a prospective study with 118 enrolled chronic HCV patients who followed a 12-week regimen of direct acting antivirals (DAAs) and were evaluated for HBV serological markers. Eventually, 98 received appropriate HBV vaccination and were assessed for response.

RESULTS

A total of 57.1% were vaccine responders although only 5.1% achieved a seroprotective level of HBsAb titre. The response rate was significantly lower among treated HCV patients with isolated HBcAb [2 (5.6%) vs. 40 (64.5%) respectively]. On multivariate analysis, advanced age [OR (95% CI) = 1.09 (1.02-1.17)] and presence of isolated HbcAb [OR (95% CI) = 39.59 (7.98-196.63)] were predictors of vaccine non-response. In our cost-effectiveness models, the cost of HBV serological screening was less than the nationally adopted non-screening approach. A model ratifying reinforced vaccination in non-responder HBcAb seropositive HCV patients would incur extra cost.

CONCLUSION

Hyporesponsiveness to the HBV vaccination is frequent in chronic HCV patients even after achieving SVR following DAAs. Although there is no consensus on the clinical management of patients with isolated HBcAb, our cost-effectiveness options may support decision-making for better clinical benefit and proper health investments.

Prevalence of Hepatitis B Virus Markers in Patients with Autoimmune Inflammatory Rheumatic Diseases in Italy

Chronic hepatitis B virus (HBV) infection may be reactivated by immunosuppressive drugs in patients with autoimmune inflammatory rheumatic diseases. This study evaluates HBV serum markers' prevalence in rheumatic outpatients belonging to Spondyloarthritis, Chronic Arthritis and Connective Tissue Disease diagnostic groups in Italy. The study enrolled 302 subjects, sex ratio (M/F) 0.6, mean age ± standard deviation 57 ± 15 years, 167 (55%) of whom were candidates for immunosuppressive therapy. The Spondyloarthritis group included 146 subjects, Chronic Arthritis 75 and Connective Tissue Disease 83 (two patients had two rheumatic diseases; thus, the sum is 304 instead of 302). Ten subjects (3%) reported previous anti-HBV vaccination and tested positive for anti-HBs alone with a titer still protective (>10 IU/mL). Among the remaining 292 subjects, the prevalence of positivity for HBsAg, isolated anti-HBc, anti-HBc/anti-HBs, and any HBV marker was 2%, 4%, 18%, and 24%, respectively. A total of 26/302 (9%) patients with γ-globulin levels ≤0.7 g/dL were more frequently (p = 0.03455) prescribed immunosuppressive therapy, suggesting a more severe rheumatic disease. A not negligible percentage of rheumatic patients in Italy are at potential risk of HBV reactivation related to immunosuppressive therapy. Before starting treatment, subjects should be tested for HBV markers. Those resulting positive should receive treatment or prophylaxis with Nucleos (t) ides analogue (NUCs) at high barrier of resistance, or pre-emptive therapy, according to the pattern of positive markers. HB vaccination is recommended for those who were never exposed to the virus.

The prevalence and significance of isolated hepatitis B core antibody (anti-HBc) in endemic population

OBJECTIVE

There are three major serologic markers for hepatitis B virus (HBV) infection: hepatitis B surface antigen (HBsAg); hepatitis B surface antibody (anti-HBs); and hepatitis B core antibody (anti-HBc). HBV screening programs, however, often test only HBsAg and anti-HBs, missing those individuals who have anti-HBc as the only detectable marker. Isolated anti-HBc can represent chronic infection in which HBsAg is not detectable by serology. We, therefore, investigated the prevalence of isolated anti-HBc in an ethnic community at moderate to high risk for HBV infection.

RESULTS

Of 7157 Korean American adults in New Jersey, 2736 (38.2%) lacked anti-HBs, potentially susceptible to HBV. Of these 2736 subjects, 771 subjects had anti-HBc. The prevalence of isolated anti-HBc increased with age: 0.8% (age 21-30); 2.4% (age 31-40); 6.05% (age 41-50); 11.7% (age 51-60); 18.3% (age 61-70); and 24.5% (age 71-91). Similarly, the percentage of the individuals with isolated anti-HBc in anti-HBs lacking subjects showed a striking age dependence. We conclude that serologic HBV screening should include anti-HBc to accurately assess the prevalence of HBV exposure. Serologic screening with only HBsAg and anti-HBs may overestimate the prevalence of non-immune population. It can also underestimate the prevalence of HBV and increase the risk of HBV reactivation during immunosuppression.

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.

Emerging Trends in Epidemiology of Hepatitis B Virus Infection

Although a vaccine against hepatitis B virus (HBV) has been available since 1982, the prevalence of adults with chronic HBV infection in sub-Saharan Africa and East Asia is still estimated at 5-10%. A high rate of chronic infections is also found in the Amazon and the southern parts of eastern and central Europe. In the Middle East and the Indian subcontinent, the prevalence is 2-5%. Less than 1% of the population of Western Europe and North America is chronically infected. Given the high prevalence of infections (such as hepatitis) among inmates, prison is considered a reservoir for facilitating such infections. Based on these premises, this current review examines and discusses emerging trends in the epidemiology of HBV infection, with particular attention to HBV infection in prison. The hepatitis B surface antigen (HBsAg) prevalence in prisoners in west and central Africa is very high (23.5%). The Centers for Disease Control and Prevention has highlighted the importance of HBV blood screening and subsequent anti-HBV vaccination in the prison population. The vaccination was recommended for all inmates, representing an opportunity to prevent HBV infection in a high-risk population. In these subjects, an accelerated hepatitis B immunisation schedule may result in rapid seroconversion for early short-term protection. Therefore, it is necessary to seek collaboration among public health officials, clinicians and correctional authorities to implement a vaccination programme.

Responses to hepatitis B vaccine in isolated anti-HBc positive adults

Immune responses of isolated anti-HBc subjects are not well characterized in populations in China. This study aimed to evaluate immune responses to hepatitis B vaccination in isolated anti-HBc positive subjects. A cohort of 608 subjects were selected and separated into isolated anti-HBc (negative for HBsAg and anti-HBs, positive for anti-HBc) and control (negative for HBsAg, anti-HBs, and anti-HBc) groups, who were matched by age and sex. All subjects received 3 doses of hepatitis B vaccine (20μg) at months 0, 1, and 3, followed by testing for serological responses 1 month after the third vaccination. The positive seroprotection rate and geometric mean titer (GMT) for hepatitis B surface antibody (anti-HBs) of isolated anti-HBc subjects were significantly lower than those in the control group(86.2% vs.92.1%, P = 0.02; 47.26 vs.97.81 mIU/mL, P < 0.001). When stratified by age, positive seroprotection rate in the isolated anti-HBc group were 92%, 88.5% and 79.4% in the 20-34, 35-49, and 50-60 y old subgroups, respectively (χ2 = 5.919, P = 0.04). Additionally, the GMT level for anti-HBs in the isolated anti-HBc group for different age subgroups were 104.43, 47.87 and 31.79 mIU/mL respectively (χ2 = 19.44, P < 0.001). The GMT level for anti-HBc before vaccination were negatively correlated with GMT for anti-HBs after 3 doses of hepatitis B vaccine (r = -0.165, P < 0.001). In conclusion, isolated anti-HBc positive subjects can achieve good immune responses after hepatitis B vaccination, and the positive seroprotection rate and GMT level for anti-HBs were lower than the control group. Better responses could be observed in young adults, and significant negative correlations were found between GMT of anti-HBc before vaccination and GMT of anti-HBs after vaccination.

Presence of anti-HBc is associated to high rates of HBV resolved infection and low threshold for Occult HBV Infection in HIV patients with negative HBsAg in Chile

HBV-HIV coinfection is prevalent. Frequently, anti-HBc is the only serological marker of HBV, which can be indicative of HBV resolved infection, when found together with anti-HBs reactivity; or present as "isolated anti-HBc," related to HBV occult infection with presence of detectable DNA HBV, more prevalent in HIV-positive individuals. Regional data about this condition are scarce. Anti-HBc rapid test has been used as screening, but its performance has not been described in HIV-positive patients. The aim of this study was determine prevalence of anti-HBc in HIV-positive patients, serological pattern of HBV resolved infection and isolated anti-HBc, evaluating presence of HBV occult infection. Assess anti-HBc rapid test compared to ECLIA. Methods included measurement of anti-HBc and anti-HBs in HIV-positive patients with negative HBsAg. Serum HBV DNA quantification and HBV booster vaccination to "isolated anti-HBc" individuals. Detection of anti-HBc by rapid test and ECLIA. In 192 patients, prevalence of anti-HBc was 42.7% (82/192); associated to male gender, drug use, men-sex-men, positive-VDRL, and longer time HIV diagnosis. 34.4% (66/192) had presence of anti-HBs, mean titers of 637 ui/ml. Isolated anti-HBc in 8.3% (16/192), associated to detectable HIV viral load and no-use of HAART; in them, HBV DNA was undetectable, and 60% responded to HBV vaccination booster. Anti-HBc rapid test showed low sensibility (32.9%) compared to ECLIA. These results show that prevalence of anti-HBc in HIV-positive individuals is high, in most cases accompanied with anti-HBs as HBV resolved infection. Low prevalence of "isolated anti-HBc," with undetectable HBV DNA, and most had anamnestic response to HBV vaccination; suggest low possibility of occult HBV infection. Anti-HBc rapid test cannot be recommended as screening method for anti-HBc.

Viral hepatitis among drug users in methadone maintenance: associated factors, vaccination outcomes, and interventions

Drug users are at high risk of viral Hepatitis A, B, and C. The prevalence of Hepatitis A, Hepatitis B, and Hepatitis C, associated factors, and vaccine seroconversion among drug treatment program participants in a randomized controlled trial of hepatitis care coordination were examined. Of 489 participants, 44 and 47% required Hepatitis A/Hepatitis B vaccinations, respectively; 59% were Hepatitis C positive requiring linkage to care. Factors associated with serologic statuses, and vaccine seroconversion are reported; implications for strategies in drug treatment settings are discussed. Results suggest generalizable strategies for drug treatment programs to expand viral hepatitis screening, prevention, vaccination, and linkage to care.

Significance of anti-HBc only in blood donors: a serological and virological study after hepatitis B vaccination

BACKGROUND

Blood donors positive only for anti-HBc may have a resolved hepatitis B virus (HBV) infection, low grade chronic infection or infection with variant strains of HBV. We aimed to assess the significance of this serological pattern after hepatitis B vaccination in such cases.

MATERIALS AND METHODS

Twenty-four anti-HBc only blood donors were vaccinated with the Engerix HBV vaccine and a serological and virological evaluation was performed before HBV vaccination and 7-10 days after each dose. Subjects were classified as non-responders if their anti-HBs levels stayed below 10 IU/L after full vaccination, while the response was considered secondary (anamnestic) if anti-HBs levels rose over 10 IU/L after the first vaccine dose, and primary if anti-HBs levels rose over 10 IU/L only after the second or third vaccine dose.

RESULTS

Of the 21 fully evaluable donors, six had no response, eight showed a primary response and seven had an anamnestic response. One non-responder had transient positivity for HBV-DNA at low levels (12 IU/mL) with persistent negativity for HBsAg.

DISCUSSION

Anti-HBc-only positive blood donors are a heterogeneous population including HBV naïve subjects with a likely false-positive anti-HBc reactivity, subjects with a resolved HBV infection, and subjects with persistent low-level HBV replication. The analysis of the anti-HBs response after a dose of HBV vaccine may help to distinguish among the different causes of the isolated anti-HBc positivity, thereby enabling proper counselling and potential readmission to blood donation.

Isolated hepatitis B core antibody positive among vaccinated cohort in Malaysia

BACKGROUND AND OBJECTIVES

Hepatitis B core antibodies (anti-HBc) are detected in almost every patient with previous exposure to hepatitis B virus (HBV). However, with this marker alone, one cannot understand the activity of the disease; therefore, this study aimed to identify the implication of isolated hepatitis B core antibody and evaluate the effect of hepatitis B vaccine booster in isolated anti-HBc among adults who received the HBV vaccine as infants.

DESIGN AND SETTINGS

A prospective cohort study of vaccinated undergraduate students of University Putra Malaysia.

PATIENTS AND METHODS

A total of 408 undergraduate students who received infant hepatitis B vaccination volunteered for this study; 5 mL of venous blood was taken from the volunteers. Hepatitis B surface antigen (HBsAg) and core antibodies were tested using a commercially available enzyme-linked immunosorbent assay kit according to the manufacturer's instructions (DRG international Inc., USA). Molecular detection of hepatitis B viral DNA was performed using nested polymerase chain reaction.

RESULTS

The prevalence of isolated anti-HBc among the vaccinated cohort was found to be 5.0%, out of which 80% had a hepatitis B surface antibodies (anti-HBs) titer higher than 10 IU/L, while 20% had less than 10 IU/L anti-HBs titer. All the anti-HBc positivesubjects had detectable hepatitis B viral DNA in their serum. Anamnestic response was found to be 100% among isolated anti-HBc with negative antibody.

CONCLUSION

Isolated anti-HBc developed protective levels of anti-HBs after a single dose of recombinant hepatitis B vaccination. HBV DNA was detected in all isolated anti-HBc indicating occult chronic HBV infection with undetectable HBsAg.

Predictors of the isolated hepatitis B core antibody pattern in HIV-infected and -uninfected men in the multicenter AIDS cohort study

BACKGROUND

The significance of hepatitis B core antibody (anti-HBc) without hepatitis B surface antigen (HBsAg) or hepatitis B surface antibody (anti-HBs) is unclear.

METHODS

This cohort study included men enrolled in the Multicenter AIDS Cohort to determine clinical and laboratory predictors of isolated anti-HBc.

RESULTS

A total of 2286 subjects (51% human immunodeficiency virus [HIV]-infected) were followed over 3.9 years. Overall, 16.9% (387) had at least 1 visit with isolated anti-HBc. The isolated anti-HBc pattern was stable 84% of the time, and transitioned to or from a pattern of past infection (anti-HBc and anti-HBs). Isolated anti-HBc was associated with HIV infection (odds ratio [OR], 2.19; 95% confidence interval [CI], 1.73-2.79) and hepatitis C virus (HCV; OR, 4.21; 95% CI; 2.99-5.91). The HCV association was stronger for chronic HCV infection (OR, 6.76; 95% CI, 5.08-8.99) than for cleared HCV (OR, 3.03; 95% CI, 1.83-5.03). HIV infection, chronic HCV, and cleared HCV infection all remained associated with isolated anti-HBc in multivariable models (OR, 1.74; 95% CI, 1.33-2.29; OR, 6.24; 95% CI, 4.62-8.42; and OR, 2.77; 95% CI, 1.65-4.66, respectively). Among HIV-infected subjects, highly active antiretroviral therapy was negatively associated (OR, 0.79; 95% CI, .66-.95) with isolated anti-HBc.

CONCLUSIONS

Isolated anti-HBc is associated with HIV and HCV coinfection, especially active HCV replication, and most commonly occurs as a transition to or from the pattern of natural immunity (anti-HBc and anti-HBs). The isolated anti-HBc pattern likely represents resolved HBV infection with low or undetected anti-HBs.

Significance and anamnestic response in isolated hepatitis B core antibody-positive individuals 18 years after neonatal hepatitis B virus vaccination in Taiwan

AIM

To investigate the significance of isolated hepatitis B core antibody (anti-HBc) and to analyze the response to hepatitis B virus (HBV) booster vaccination in young adults with isolated anti-HBc who had been fully vaccinated with HBV vaccine as infants.

MATERIALS AND METHODS

We screened 1734 new university entrants who had been fully vaccinated against HBV in infancy for the presence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and anti-HBc upon university entry. Results positive for isolated anti-HBc were reconfirmed by testing for the presence of HBsAg and anti-HBc once more, and further evaluated for anti-HCV, anti-HIV, and HBV DNA status 6 months later. Students were also offered HBV booster vaccinations at that time. Geometric mean titers (GMT) of anti-HBs after one booster dose of HBV were compared between students with isolated anti-HBc and students with HBV naïve status.

RESULTS

The overall prevalence of isolated anti-HBc in our student cohort was 1.2% (21 of 1734). No evidence of occult HBV infection was observed. A "booster" anamnestic response (anti-HBs titer ≥ 10 mIU/mL) was noted in 95% (20 of 21) of subjects with isolated anti-HBc. After re-measurement of anti-HBc, 13 (62%) of the 21 subjects with isolated anti-HBc were reclassified as having resolved HBV infection with a loss of anti-HBs. In the remaining 8 subjects (38%), isolated anti-HBc was determined to be false positive. The HBV status of these 8 subjects was HBV naïve due to the waning-off effect of anti-HBs of the neonatal HBV vaccination. There was no significant difference in anamnestic response to a single HBV booster dose of vaccine between students with isolated anti-HBc (n=13) and those with HBV naïve (n=323) status (GMT 50.6 vs 47.7 mIU/mL, P=0.90).

CONCLUSION

The presence of isolated anti-HBc 18 years after HBV vaccination can be attributed to post-HBV infection with a loss of anti-HBs and to a decline in anti-HBs elicited by vaccine. A single HBV booster dose of vaccine is recommended for subjects with isolated anti-HBc who were fully vaccinated with HBV vaccine as infants. This finding needs to be replicated in further studies with larger cohorts.

Seroprevalence of hepatitis B and C infection markers among children and adolescents in the southern Brazilian region

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. The aim of this study was to determine the prevalence of HBV and HCV serological markers among children and adolescents and verify the epidemiology of the HBV infection over than a decade of the introduction of vaccination program. Serologic markers to HBsAg, total anti-HBc and anti-HCV had been tested in 393 samples. The seropositivity for HBsAg was 0.76% and for total anti-HBc was 1.02%. Copositivity between HBsAg and total anti-HBc was verified in 0.76% of the analyzed samples. There was no seropositivity for anti-HCV marker. The seroprevalence of HBV infection markers among children and adolescents in the southern Brazilian region is high compared to that reported in other countries. Preventive measures, such as educational activities in addition to the universal childhood HBV vaccination, should be initiated in order to reduce the morbimortality and the economic burden associated with the disease.

Anti-hepatitis B core antibody is not required for prevaccination screening in healthcare workers. Vaccine. 2011;29:1721-1726. [PMID: 21147128 DOI: 10.1016/j.vaccine.2010.11.044]

Vaccination against hepatitis B virus (HBV) is recommended for health care workers (HCWs), but it is not clear whether HBV vaccination is required for HCWs who have isolated antibody to hepatitis B core antigen (anti-HBc), or whether prevaccination screening for anti-HBc is needed in HCWs. Among 1812 HCWs, subjects with isolated anti-HBc and those with no HBV markers (control) were screened. The anamnestic response (antibody to hepatitis B surface antigen over 50 mIU/mL after the first vaccine injection) was compared prospectively between the two groups. The prevalence of isolated anti-HBc was 2.3%. Their anamnestic response was lower than that of controls (27.5% vs. 46.9%, P=0.020). The subjects who had isolated anti-HBc were older and predominantly male, compared with the controls. Multivariate analysis revealed that age (odds ratio [OR], 0.67; confidence interval [CI], 0.51-0.90) and prior vaccination (OR, 3.36; CI, 2.04-5.54) were independent predictors of the anamnestic response, regardless of the anti-HBc status. Serum HBV DNA was not detected in any subject. Anti-HBs seroconversion was achieved in most of the anti-HBc-positive subjects after full vaccination, and the rate was comparable with controls (89.5% vs. 96.6%, P=0.067). Isolated anti-HBc-positive HCWs are rare and most of them respond to vaccination. Anti-HBc testing is not a prerequisite for vaccination. This serology suggests a loss of acquired anti-HBs rather than occult HBV infection. Their reduced immunity to vaccination may be related to old age.

European guideline for the management of hepatitis B and C virus infections, 2010

These are the guidelines on hepatitis B and C management for IUSTI/WHO in Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of hepatitis B and C with particular reference to sexual health clinical practice.

The underlying mechanisms for the 'anti-HBc alone' serological profile

The serological pattern, "anti-HBc alone", characterized by the presence of antibodies against the core antigen of hepatitis B virus (anti-HBc) as the only marker of hepatitis B, is not rare in a diagnostic setting. Depending on the prevalence of HBV infection and the patient group investigated, 1-31% of positive anti-HBc results are isolated positive findings. Anti-HBc alone is frequently observed in intravenous drug addicts, HIV-infected individuals, patients who are coinfected with HBV and hepatitis C virus, and pregnant women. However, it is not clear how this profile should be interpreted. Several studies have shown that anti-HBc alone is not only compatible with acute and resolved HBV infection but also with chronic infection. The reasons for the lack of HBsAg and anti-HBs in anti-HBc-alone individuals are not clear, but several mechanisms and possibilities have been suggested that could explain this phenomenon, some of which are delineated in this article.

Hepatitis B vaccination in HIV-infected adults: current evidence, recommendations and practical considerations

Immunization with hepatitis B (HBV) vaccine is recommended for all HIV-infected individuals without immunity to HBV. This patient population, however, has relatively poor HBV vaccine responses. Factors associated with this impaired HBV vaccine response in HIV-infected individuals may include older age, uncontrolled HIV replication, and low nadir CD4 cell count. Postvaccination testing for HBV surface antibody is recommended and vaccine non-responders should undergo repeat immunization with a full series. The benefit of double dosage, the appropriate strategy for HIV-infected patients with isolated HBV core antibody and the timing and number of vaccinations in persons with advanced immunosuppression on highly active antiretroviral therapy remain controversial areas.

HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study

OBJECTIVES

Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown.

METHODS

A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005.

RESULTS

The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg.

CONCLUSIONS

The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.

Hepatitis B vaccine: a seven-year study of adherence to the immunization guidelines and efficacy in HIV-1-positive adults

BACKGROUND

Vaccination against hepatitis B virus (HBV) has been recommended for all high-risk adults since 1982. Since the advent of highly active antiretroviral therapy, few studies have examined adherence to the Infectious Diseases Society of America (IDSA) and Advisory Committee on Immunization Practices (ACIP) guidelines for hepatitis B vaccination in persons infected with HIV.

METHODS

This was a seven-year retrospective, cross-sectional analysis of HBV vaccination practices in HIV-1-positive adults treated in an urban ambulatory care center. Compliance with screening, hepatitis B vaccination recommendations, and response to vaccination were assessed.

RESULTS

Of the 1601 charts reviewed, 717 persons were eligible for vaccination against hepatitis B. Of these patients, 503 received at least one dose of vaccine, but only 356 patients completed the three-dose series. Vaccine response was associated with CD4 count (p=0.006) and viral load (p=0.001) at the time of the first dose. However, development of hepatitis B surface antibody was seen at all CD4 counts and viral loads. The multivariate analysis showed only the HIV viral load was predictive of immunologic response. Twenty of the vaccine-eligible patients who did not receive vaccination were infected with HBV during the study period. No vaccinated persons contracted hepatitis B.

CONCLUSION

Failure to implement these guidelines represents a missed opportunity to prevent disease. In our study, HIV viral load was better than CD4 count as a predictor of response to the HBV vaccination. However, neither low CD4 count nor high HIV viral load should be used as justification to delay vaccination of high-risk persons.

Hepatitis B vaccines

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic dis-ease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Hepatitis B virus infection in adolescents in a rural township—15 years subsequent to mass hepatitis B vaccination in Taiwan

In Taiwan, decrease of both infection and carrier rates of hepatitis B virus (HBV) have been documented especially in metropolitan areas after universal HBV vaccination. This study investigated HBV infection status in a rural township 15 years after the program began. Three cross-sectional studies were conducted in 1999, 2000 and 2003, to recruit all the students of the only junior middle school, born from July 1984 to June 1991, in a township in central Taiwan. Serum samples were tested for HBsAg, anti-HBs and anti-HBc. Subjects identified to be neither positive for HBsAg nor anti-HBs were given a booster dose of HBV vaccine. Subjects lacking an anamnestic anti-HBs response were given a complete 3-dose vaccination. A total of 1454 (98.5%) students responded. The prevalence rate of HBsAg decreased 57% [from 12.5% in 1984 to 5.4% in 1991, P < 0.005 (chi2-test for linear trends)], and anti-HBc positive rate dropped 68% (from 31.9 to 10.2%, P < 0.001). An anamnestic anti-HBs response developed after a vaccine booster among 433 (72%) anti-HBs negative and 12 (66.7%) anti-HBc alone subjects. And 93 (94.9%) anti-HBs negative and 1 (16.7%) anti-HBc alone subject developed a primary anti-HBs response after catch-up vaccination. Viremia was detected for two anti-HBc alone subjects without anamnestic or primary response. The vaccination program has decreased the number of those infected and carrier rates in either urban or rural areas in Taiwan. However, the prevalence of HBsAg and anti-HBc in rural area were much higher than urban area.

Study of hepatitis B (HB) vaccine non-responsiveness among health care workers from an endemic area (Taiwan)

OBJECTIVE

To evaluate the etiology of non-responsiveness to hepatitis B (HB) vaccination in adults from an endemic area.

METHODS

A total of 250 subjects who were HBsAg negative and anti-HBs<10 mIU/ml received three-dose HB-vaccine series. Anti-HBs 'negative' was defined as a level<1.5 mIU/ml. 'Weakly' positive was defined as 1.5-10 mIU/ml at pre-vaccination testing. Anti-HBs response was defined as a level >10 mIU/ml at post-vaccination testing. Among non-responders who were anti-HBc positive, serum anti-HBe and hepatitis B virus (HBV) DNA were tested.

RESULTS

Three variables were associated with non-responsiveness by univariate analysis: anti-HBc positive, male gender, and age >40 years. Multivariate analysis additionally showed that anti-HBs negative was associated with non-responsiveness. Among 23 non-responders in anti-HBc positive subjects, post-vaccination serum was available in 16 subjects. HBV-DNA in all subjects was under detectable level by PCR assay. Anti-HBe positive were found in 13 of 16 subjects and were assumed to be occult HBV infection.

CONCLUSION

Male gender, age >40 years and anti-HBc positive are associated with non-responsiveness to HB vaccination. Most of non-responders among anti-HBc positive subjects were assumed to be occult HBV infection. Subjects with weakly positive anti-HBs were associated with responsiveness which may be the effect of immune memory.

Hepatitis B vaccination in a hyper-endemic tribal community from India: assessment after three years

Hepatitis B infection is highly endemic among the primitive tribes of Andaman and Nicobar Islands, India and it is necessary to initiate hepatitis B vaccination for control of this infection. A pilot project of mass hepatitis B vaccination using indigenously developed vaccine was initiated among Nicobarese tribe of Car Nicobar Island. Sero-protection rates after second and third year were 89% and 85.5%, respectively. The rate of chronic infection in the vaccinated population after three years was 1.86% compared to the pre-vaccination rate of 20.7%. Considering high sero-protection rates and low cost, the indigenous vaccine could be used for vaccination programme in this tribal community.

Significance of anti-hbc in the absence of other hepatitis B markers in a college-aged population

A study of 291 college students in the Houston (Tex., USA) area was performed to determine the relationship between alanine aminotransferase (ALT) level and antibodies to the hepatitis B virus (HBV) core antigen (anti-HBc) in the absence of other HBV markers (referred to as isolated anti-HBc). Participants were drawn from three groups: those positive only for anti-HBc (cases), those positive for hepatitis B surface antigen, a marker of acute/chronic HBV infection (control group 1), and those with no previous exposure to the HBV (control group 2). There were no significant differences between the groups in percentages of subjects with an elevated ALT level. The mean ALT level from active HBV infections was highest with HBV-negative controls having the lowest mean ALT concentration (p = 0.06), but no significant differences were found between ALT levels of those with isolated anti-HBc and either control group. This study may further aid in determining the presence of any liver damage when testing positive only for the antibodies to HBc.

Recent developments in the diagnosis and monitoring of HBV infection and role of the genetic variability of the S gene

Recent developments in the laboratory diagnosis of hepatitis B virus infection include the optimization of key serologic markers, including hepatitis B virus surface antigen and antihepatitis B virus core antibody, as well as the development of automated nucleic acid amplification assays. There is still a lack of standardization for nucleic acid amplification assays that are used for the monitoring of antiviral therapy and follow-up of chronic infection and the clinical significance of hepatitis B virus DNA levels need to be clarified. Although highly sensitive automated nucleic acid amplification assays for blood donor screening are available, their implementation is still subject to discussion and certain countries rejected hepatitis B virus DNA testing for blood donation due to poor cost effectiveness. Genetic variability of hepatitis B virus constitutes a major challenge for diagnosis of hepatitis B virus infection, particularly with regard to hepatitis B virus surface antigen detection, antihepatitis B virus surface antigen quantification and nucleic acid amplification assays. The performances of hepatitis B virus surface antigen enzyme immunoassays in regard to genotype and surface antigen variability need to be further improved. Polyclonal antibody-based hepatitis B virus surface antigen enzyme immunoassays, although they cannot guarantee 100% sensitivity, demonstrate superior S gene mutant recognition to assays using monoclonal capture and tracer antibodies. Isolated antihepatitis B virus core reactivity is an unusual but frequent result, which requires a test algorithm for resolution and hepatitis B virus DNA detection with sensitive nucleic acid amplification assays in order to exclude occult hepatitis B virus infection.

Hepatitis B vaccines

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic disease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Immunogenicity of combined hepatitis A and B vaccine in elderly persons

More and more elderly people travel to areas where hepatitis A and B are endemic. Their immune system is less effective than in young persons. Therefore, it has to be insured that these travelers have protective immunity after vaccination. In a retrospective study we measured anti hepatitis virus (anti-HAV) and anti-HBs in elderly persons (N = 104, mean age 54 years) after combined hepatitis A/B vaccination under every-day conditions. After complete vaccination only 36 (34.6%) had antibodies against both viruses. Only 23 (29%) of 80 vaccinees older than 40 years were protected against hepatitis B and 52 (65%) against hepatitis A. The response to the vaccination decreased with increasing age. Vaccination against hepatitis B-but not against hepatitis A-was also influenced by the presence of chronic disease. After one booster 87% of the anti-HAV negative vaccinees developed protective anti-HAV antibodies. Anti-HBs can be expected in about 50% of the HBV negative vaccinees with every single booster. These results indicate that combined hepatitis A/B vaccination is not very effective in elderly persons. After complete vaccination their anti-HAV and anti-HBs antibodies have to be controlled to insure protection. In case of vaccination-failure boosters are very effective.