Prevalence of anti-hepatitis B surface antibodies among children and adolescents vaccinated in infancy and effect of booster dose administered within a pilot study

Impaired humoral immune response to hepatitis B vaccine in patients on maintenance hemodialysis

Hepatitis B virus (HBV) infection is a worldwide health problem. We aimed in this study to investigate the humoral immune response derived to HBV vaccine following completing the vaccine series in Madinah. Two hundred and two Saudi hemodialysis (HD) patients were included in this cross-sectional study. Mean concentration of Hepatitis B surface antibody (anti-HBs) was significantly higher among patients who received the vaccination twice compared to patients who received the vaccination only after starting hemodialysis (252 ± 489 mIU/mL vs. 144 ± 327 mIU/mL, respectively, p = 0.008). Almost half of the study sample were non-protected and showed anti-HBs concentration < 10 mlU/mL. In contrast, 20.3% (n = 41) were identified as poor responders (10-100 mlU/mL) and only 28.2% (n = 57) were identified as good responders (10-100 mlU/mL). However, the latter two groups were accounted as protected (48.5%, n = 98). Patients sex was associated with anti-HBs concentration (non-responders; poor responders; good responders), where significantly higher proportion of good responders were females compared to males (p = 0.007). In conclusion, HBV vaccine is efficient to elicit humoral immune response in hemodialysis patients.

Hepatitis B Vaccination in Children With Ongoing Cancer Treatment: A Safety and Efficacy Study of Super-Accelerated Vaccination Scheme

OBJECTIVE

Children with cancer have an increased risk for hepatitis B virus (HBV) infections due to chemotherapy-induced secondary immunodeficiency and frequent blood transfusions. The aim of this study is to evaluate the efficacy and safety of hepatitis B vaccination during the intensive induction chemotherapy in children with cancer found to be seronegative for hepatitis B on admission.

MATERIALS AND METHODS

Children newly diagnosed with cancer were evaluated for the presence of hepatitis B surface antigen (HBsAg) and antibody on admission. The children negative for both were included in the study. A super-accelerated vaccination scheme (3 booster doses at days 1-5, 8-12, and 28-33) was administered to these seronegative children concurrently with induction chemotherapy. Antibody response was checked 4-8 weeks after the last vaccination and 6 months after the end of the treatment.

RESULTS

Eleven out of 122 children were seronegative for hepatitis B on admission (9%). Acute lymphoblastic leukemia, lymphoma, and solid tumors were diagnosed in 5, 4, and 2 children, respectively. Complete seroconversion was achieved in 4-8 weeks after the last vaccination with high titers of anti-HBs antibody, and all patients remained antibody-positive until 6 months after the completion of chemotherapy.

CONCLUSION

The risk of transfusion-related infections increases with a number of transfused products and donor exposures, and it is more significant for immunosuppressed children with hematologic and oncologic malignancies. Hepatitis B vaccination could safely be applied with brisk and sustained responses in this vulnerable population, based on the local epidemiological data.

The Israel National Sera Bank: Methods, Representativeness, and Challenges

The Israel National Sera Bank (INSB) was established in 1997 in the Israel Center for Disease Control. The purpose of the INSB was to provide policymakers with data on the immunity status of the Israeli population against vaccine-preventable diseases, and on the extent and characteristics of exposure to emerging and re-emerging infectious diseases. The aim of this paper is to describe the methods, representativeness, and challenges in maintaining the INSB. The INSB comprises residual sera collected in six laboratories. By the end of 2019, 138,898 samples had been deposited in the INSB. These include samples from four community laboratories: 30.7% from the National Blood Service, 22.2% from Haifa and the Western Galilee, 21.7% from Soroka, and 0.7% from Jerusalem; and from two medical center laboratories: 18.6% from Schneider and 6.1% from Mayanei Hayeshua. The demographic characteristics of the sample at the end of 2019 closely resembled those of the general population. The main challenges addressed in maintaining the INSB relate to its representativeness, the possibility of repeated donors, costs, stability of antibody levels after long-term storage, ethical aspects, and the data available for each sample. The INSB is a unique, powerful, and necessary tool for assessing population immunity levels, based on serum samples collected over a long period of time.

Protective effect of vaccinating infants with a 5 µg recombinant yeast-derived hepatitis B vaccine and the need for a booster dose in China

In 2002, China integrated hepatitis B vaccine (HepB) into its Expanded Program on Immunization (EPI) using HepB vaccine containing 5 µg of antigen. Although not recommended nationally, there was a common clinical practice in China of screening children for anti-HBs antibody level and giving a booster dose to HBV surface antigen (HBsAg)-negative children with non-protective anti-HBs antibody levels. We report an evaluation of the protective effectiveness of the 5 µg HepB vaccine and the serological response to the booster dose. We used data from a 2014 hepatitis B serological survey to determine HBsAg positivity and anti-HBs antibody levels among children who received and did not receive a booster dose. We determined HepB coverage from the Children Immunization Information Management System (CIIMS). We obtained and analyzed reports of acute Hepatitis B (AHB) during 2008-2014 obtained from the National Notifiable Disease Reporting System (NNDRS). The HBsAg-positive rate among children who had not received a booster dose was 0.41%, and did not increase with age (i.e., time since infant immunization). The anti-HBs positivity rate among the 6% of children who received a booster dose (88.41%) was higher than among those who had not received a booster (60.85%); anti-HBs antibody levels declined with age regardless of booster dose status. There was no statistically significant difference in HBsAg positivity between children who received a booster dose and those who did not. The AHB incidence among children born between 2002 and 2007 did not increase with age. Use of routine 5 µg HepB vaccine was not associated with an increase in AHB or of HBsAg positivity by time since vaccination, providing supportive evidence that individuals vaccinated with the 5 µg HepB vaccine do not need a booster dose. Although a booster dose was associated with increases in anti-HBs antibody levels, our study provided no evidence to support the need for this clinical practice. We should continue to strengthen serological monitoring of children, especially for those born to HBsAg positive mothers.

Administering an additional hepatitis B vaccination dose after 18 years maintains adequate long-term protection levels in healthcare workers

Background: HBV (hepatitis B virus) vaccination in first year of life is recommended to prevent infection. Observational studies have suggested that vaccination at birth provides protection for 90% of the population for 30 years. Data on response to booster doses and long-term protection are lacking.Methods: We compared HBV antibody levels of healthcare students who were immunized for HBV with a primary series during their first year of life (primary) to students who were immunized with a primary series and received an additional dose at age 18 (boosted) four years earlier. Antibody titres ≥10 mIU/mL were considered adequate. Those that were inadequate received another dose and were reassessed.Results: We assessed 381 students, 80.1% were primary and 19.9% boosted. A significantly higher percentage of students in the boosted group had antibody titre levels ≥10 mIU/mL compared to primary group (88.1% vs. 41.3%, p < .001). Of 179 students in the primary group with inadequate antibody levels, 134 received a booster dose and 126 of them (94%) developed anti-HBs levels ≥10 mIU/mL. Of 9 students with inadequate levels in the boosted group, 8 received another booster dose and all developed adequate levels.Conclusions: Primary vaccination against HBV at birth does not necessarily provide lifelong adequate antibody levels. Boosting at 18 years reinforces antibody levels for at least four more years. Current guidelines recommend testing and boosting all medical personal. Based on our study, it may be prudent to extend this practice to all individuals who are at higher risk.

Population seroprotection against hepatitis a virus in Israel 18 years after introduction of inactivated vaccine into the routine childhood vaccination schedule

Vaccine against Hepatitis A virus (HAV) is part of the routine vaccination schedule in Israel since 1999. As of 2016, new recruits to the Israel Defense Forces should have been vaccinated in their childhood. This sero-survey aimed to determine immunity against HAV 18 years after childhood vaccination, and to re-evaluate the need for HAV vaccination booster upon recruitment. Two populations were studied: soldiers who were recruited during 2011-2012, who belonged to birth cohorts before childhood vaccination (BCV) was introduced; and recruits from 2017, who belonged to birth cohorts after childhood vaccination (ACV) was introduced. Data on 339 BCV recruits and 295 ACV recruits were analyzed. Seropositivity was 35% in the BCV group and 68% in the ACV group (P < 0.0001). Seropositivity rates among ACV subjects enable evaluation of the vaccination program's impact on the population. Our findings do not support discontinuation of HAV vaccination of at risk groups until further evaluation.

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.

Long-term immunity to hepatitis B following vaccination in infancy: Real-world data analysis

BACKGROUND

Hepatitis B virus (HBV) vaccination has decreased the prevalence of chronic HBV infections and their sequelae. However, whether vaccination at birth provides lifelong protection is unclear.

OBJECTIVE

To assess long-term immunity following neonatal HBV immunization in a large population-based cohort.

METHODS

Using the database of a 2 million member sick fund in Israel, we identified all subjects born after introduction of universal HBV vaccination in Israel (January 1992 through December 2014), that were tested for hepatitis B surface antibody (anti-HBs Ab's). Years since vaccination were categorized into 5-year groups and linear trends in the seroprevalence of HBV immunity were calculated. Anamnestic response and presence of Hepatitis B surface antigen (HBs Ag) were assessed.

RESULTS

Included were 20,634 tested individuals. Mean (±SD) age at testing was 14.8 (±5.4) years. Mean anti-HBs Ab levels declined with time to 16.39 mIU/ml in the 15-20 year group (P < 0.001). The proportion of negative results increased gradually (P < 0.001) to 66.7% after 15 years. Anamnestic response assessment showed that 604 of 644 seronegative subjects (93.8%, 95% CI: 91.6-95.5%) became seropositive after a booster dose. HBs Ag was identified in 91 of the 20,634 (4.4 per 1000 study participants).

CONCLUSIONS

Following vaccination, anti-HB's Ab's progressively decline, with only a third of the population retaining protective levels after 15 years. In adolescence, anamnestic response shows that nearly all revaccinated adolescents exhibit immunity. A low rate of Hepatitis B infection was demonstrated despite vaccination of nearly all newborns.