The persistence of anti-HBs antibody and anamnestic response 20 years after primary vaccination with recombinant hepatitis B vaccine at infancy

Hepatitis B burden and population immunity in a high endemicity city - a geographically random household epidemiology study for evaluating achievability of elimination

This study aimed to provide reference for evaluating the achievability of hepatitis B virus (HBV) elimination in a high endemicity city with universal neonatal vaccination in place for over 30 years. Between September 2018 and October 2020, 2085 citizens from 1143 geographically random households in Hong Kong completed a questionnaire and had blood-testing for HBV markers (anti-HBs, HBsAg, anti-HBc, HBeAg). We evaluated the epidemiology and examined factors associated with HBV exposure, vaccination and chronic diseases. The proportion of households with HBsAg positive index participants was 9.2% (95% CI 7.5%-10.9%). The age- and sex-adjusted HBsAg prevalence was 6.3% (95% CI 5.3%-7.4%), compared to >10% in those born in 1960-1970 and among non-local born citizens, and <1% in people born after introduction of neonatal vaccination. Among 155 HBsAg positive participants, 59% were aware of their infection status with 10% on treatment and 10/150 (6.7%) HBeAg positive. More than 40% (872/2064) tested negative for both HBsAg and anti-HBs, contributed by the lack of immunity in older adults and the waning immunity of vaccines. Hong Kong has remained at high-intermediate HBV endemicity state. The moderate level of anti-HBs positivity and very low treatment coverage (10%) among HBsAg positive participants pose challenges for achieving the HBV elimination target.

The seroprevalence of the hepatitis B virus in Italian medical students after 3 decades since the introduction of universal vaccination

OBJECTIVES

Since 1991 hepatitis B vaccination has been mandatory for all newborns in Italy. The aim of the study was to verify the long-term seroprevalence and the efficacy of hepatitis B vaccination in medical students of the University of Siena.

MATERIAL AND METHODS

A cross-sectional observational study was conducted on a population of 850 medical students of the University of Siena (322 males and 528 females, mean age: 23 years) by obtaining from the medical reports the serological analysis data for the total anti-hepatitis B antibodies (HBsAb) and information on hepatitis B vaccination (number of vaccine doses, age at the first vaccination, time since the final vaccination dose, country of origin). Raw odds ratios (ORs) and 95% confidence intervals (CIs) were initially calculated to evaluate the association between 2 variables. The adjusted ORs were then calculated using a multivariate logistic regression model to study the association between the variables and the possible confounding factors.

RESULTS

Overall, 593 students (69.76%) were immunized against hepatitis B, while 257 (30.24%) had HBsAb antibody titer <10 mIU/ml. From the OR calculation, an inverse correlation emerged between seropositivity to hepatitis B and age, and between seropositivity to hepatitis B and the age at the first vaccination dose. There was also a correlation between seropositivity and the number of vaccination doses received. By performing the multivariate logistic analysis, correlations with these variables were confirmed.

CONCLUSIONS

A significant part of the studied population was not immunized against hepatitis B virus, despite the fact that vaccination had been carried out as prescribed by law. The results of the study reaffirm the importance of health surveillance in subjects at biological risk such as medical students. Int J Occup Med Environ Health. 2022;35(1):75-80.

Re-examining Hepatitis B Postexposure Prophylaxis Following Pediatric Community-acquired Needle-stick Injury in an Era of a National Immunization Registry

BACKGROUND

Long-term hepatitis B immunity has been demonstrated following the completion of the primary vaccination series in childhood. Some guidelines recommend a hepatitis B surface antibody (anti-HBs) directed approach following community-acquired needle-stick injury (CANSI) to inform hepatitis B postexposure prophylaxis (PEP) management. We assessed the utility of anti-HBs testing post-CANSI, as well as the costing of, and adherence to PEP at a pediatric hospital.

METHODS

Children presenting to an Australian tertiary pediatric hospital post-CANSI (2014-2019) were identified retrospectively using medical and laboratory records. Immunization status was obtained from the Australian Immunisation Registry.

RESULTS

Fifty-six children with CANSI were identified. Of those with immunization records, all had completed hepatitis B vaccinations (n = 52). At presentation, 44% (n = 23) had anti-HBs <10 IU/L, which was more likely in older (≥6 years, 68%) versus younger children (OR 4.59, P < 0.02). HBIG and hepatitis B vaccine adherence was 65% (15/23) and 78% (18/23), respectively. All children (n = 14) with anti-HBs ≥4 weeks postvaccination ±HBIG, demonstrated an anamnestic response. No hepatitis B infections were detected. Using completed immunizations versus anti-HBs levels as a marker of immunity to direct PEP resulted in a projected cost savings of AUD$ 4234.

CONCLUSION

Anti-HBs levels <10 IU/L, despite previous vaccinations, were frequent in children post-CANSI, with many demonstrating an anamnestic response. Adherence to postexposure HBIG and hepatitis B vaccine was suboptimal using an anti-HBs directed approach. These data support re-evaluating PEP in an era of the national immunization registry; completion of hepatitis B vaccinations as a marker of immunity provides a practical approach, ensuring optimized care for pediatric CANSI.

Undetectable Anti-HBs Antibodies: Need of a Booster Dose for HIV-1-Infected Individuals

HBV vaccination effectively prevents HBV transmission and the development of liver cancer. Disease progression and liver-related complications are more common in HIV-1/HBV co-infected than HBV mono-infected individuals. A considerable body of literature, which will be reviewed here, indicates that response to HBV vaccine is suboptimal in HIV-1-infected individuals and that the poor maintenance of protective immunity to HBV vaccines in these individuals is an important medical issue. Several factors affect HBV vaccine response during HIV-1 infection including CD4+ T cell counts, B cell response, vaccine formulation, schedules, and timing of antiretroviral therapy (ART). The initial response to HBV vaccination also plays a critical role in the sustainability of antibody responses in both HIV-1-infected and uninfected vaccinees. Thus, regular follow-up for antibody titer and a booster dose is warranted to prevent HBV transmission in HIV-1 infected people.

Immune persistence induced by three doses of 60 μg hepatitis B vaccine in non-responders following standard primary vaccination in Chinese adults

This study consisted of two rounds of cross-sectional observations designed to evaluate the persistence of immune protection induced high antigen content hepatitis B (HB) vaccine at 60 μg/1.0 ml formulations administered at a three-dose schedule (Days 0, 28, and 56) in non-responders to routine HB vaccination. In the original phase 3 study, we enrolled 1091 healthy participants (16-60 years old) seronegative for antibody against HB surface antigen (anti-HBs) after primary vaccination. Participants were randomized (2:2:1) to receive three booster doses of HB vaccine containing 60 μg, 30 μg, or 10 μg of antigen per dose 28 days apart. In the group receiving the 60 μg HB vaccine, 428 participants' serum samples were available at pre-vaccination and 28 days after each vaccine dose and were included in immunogenicity analysis. With two written informed consents, we collected blood samples from 276 (67.2%) participants in 2014 and 239 (58.2%) in 2019, who had completed the full course of revaccination and reached the seropositive (anti-HBs≥10 mIU/ml) standard in the 60 μg vaccine group of the original phase 3 study. The HBV seropositive rate was found to decrease from 96.0% in 28 days after receiving the third dose of 60 μg HB vaccine, to 48.2% in 2014, and to 40.6% in 2019, with anti-HBs GMC of seropositive individuals was 584.0 mIU/ml, 142.4 mIU/ml, and 169.1 mIU/ml, respectively. Analysis of 181 vaccinees who had serologic test results available both in 2014 and in 2019, and results revealed a dynamic trend in anti-HBs titer similar to that for the whole immune persistence cohort. Of paramount importance, the serologic test results found that 24.9% (45/181) participants had higher anti-HBs concentrations in 2019 than in 2014, this could be interpreted as natural boosters, secondary to HBV exposure without infection because protected. In conclusion, protective antibody persists about 11 years after immunization of Chinese non-responders with 3 doses of 60 μg HB vaccine. Booster doses of vaccine do not seem necessary to ensure long-term protection.

HBV Seroprotection and Anamnestic Response to Booster Vaccination in Pediatric Cancer Survivors

Hepatitis B is a major global health concern and can be prevented in the era of vaccination. Impaired immunological memory to primary immunization is a common chemotherapy-related complication among cancer survivors. The study aimed to determine protective immunity against hepatitis B virus (HBV) and anamnestic response to booster vaccination. In all, 107 pediatric cancer survivors previously immunized with primary hepatitis B vaccination were enrolled. A hepatitis B booster dose was administered to those with suboptimal seroprotection (anti-HBs < 10 mIU/mL) and 2 additional doses were subsequently administered at 1 and 6 months to those whose anti-HBs remained low. Clinical and serologic parameters were analyzed. Sero-protective rate against HBV (anti-HBs ≥ 10 mIU/mL) among survivors was 20.6% with geometric mean titer (GMT) of 95.7 ± 265.6 mIU/mL. Anamnestic response was 61% after a booster vaccine among those with suboptimal seroprotection and 100% after 2 additional booster doses among those whose anti-HBs remained low. GMTs among those survivors after the First and third booster vaccines were 320.0 ± 412.4 mIU/mL and 826.5 ± 343.8 mIU/mL, respectively. Age at diagnosis was a significant independent risk factor for adequate seroprotection (adjusted OR = 0.84, 95%CI: 0.71-0.99) with a P-value of .034. No associated risk factors to predict optimal anamnestic response to booster vaccination were identified. Loss of immunological memory to primary hepatitis B immunization is an inevitable complication among most pediatric cancer survivors; therefore, assessing adequate seroprotection is essentially required. For those with limited accessibility to serologic tests, completion of full 3-booster-dose series is alternative and highly recommended.

The positive rates of hepatitis B surface antibody in youths after booster vaccination: a 4-year follow-up study with large sample

BACKGROUND

Hepatitis B virus (HBV) infection is still a public issue of the world. Hepatitis B vaccination is widely used as an effective measure to prevent HBV infection. This large-sample study aimed to evaluate the positive rates of hepatitis B surface antibody (anti-HBs) in youths after booster vaccination.

METHODS

A total of 37,788 participants were divided into two groups according to the baseline levels of anti-HBs before booster vaccination: the negative group (anti-HBs (-)); the positive group (anti-HBs (+)). Participants were tested for anti-HBs levels after receiving a booster vaccine 1 year and 4 years.

RESULTS

The positive rates of anti-HBs were 34.50%, 73.8% and 67.32% before booster vaccination at 1 year and 4 years after vaccination, respectively. At four years after the booster vaccination, the positive rates of 13 to 18 years were 47.54%, which was the lowest level among all youths age groups. In the anti-HBs (-) group, the positive conversion rates of anti-HBs were 74.62% at 1 year after receiving a booster vaccine, and 67.66% at 4 years after vaccination. In the anti-HBs (+) group, the positive maintenance rates of anti-HBs were 70.16% after 1 year, and 66.66% after 4 years. Compared with the baseline anti-HBs (+) group, the positive rates of the baseline anti-HBs (-) group were higher at 1 year and 4 years after receiving the booster vaccine.

CONCLUSIONS

 The positive rates of anti-HBs declined over time, especially the positive maintenance rates were the lowest at age of 13 to 18 years.

Antibody responses to prophylactic quadrivalent human papillomavirus vaccine at 48 months among HIV-infected girls and boys ages 9-14 in Kenya, Africa

OBJECTIVES

HIV infected children remain at increased risk of HPV associated malignancies as they initiate sexual activity. Though they mount a vigorous immune response to the quadrivalent human papillomavirus (QHPV-6, -11,-16, and -18; Gardasil®) vaccine, durability of the immune response is uncertain. We assessed antibody responses to HPV 6, -11, -16 and -18 for up to 48 months following administration of quadrivalent human papillomavirus vaccine in HIV-infected girls and boys ages 9-14 years in Kenya.

DESIGN

Of 178 girls and boys who had previously received three doses of the quadrivalent HPV vaccine, 176 enrolled into extended follow up for 4 years. HPV antibodies to -6, -11, -16 and -18 were measured at 24, 36 and 48 months after the first vaccine dose using the total immunoglobulin G immunoassay (IgG LIA). We evaluated the magnitude and trend in HPV vaccine response and the effect of plasma HIV-1 RNA on HPV vaccine response from month 24 to month 48 of follow up.

RESULTS

At re-enrollment, 24 months after initial vaccination, median age of participants was 14 years (range 11-17); 167 (95%) were receiving antiretroviral therapy and 110 (66%) had plasma HIV RNA < 40 copies/mL. The rate of HPV seropositivity at 48 months was 83% for HPV-6; 80% for HPV-11; 90% for HPV-16; and 77% for HPV-18. There was a plateau in mean log10 HPV-specific antibody titer between month 24 and 48. The mean log10 HPV-type specific antibody titer for children with undetectable HIV viral load (<40) at the time of vaccination consistently remained higher for the 48 months of follow up compared to children with detectable viral load.

CONCLUSION

Children with HIV infection may retain long term antibody response following HPV immunization. Further work to define whether HIV-infected children are protected from HPV acquisition with low levels of HPV antibodies is needed.

Evaluation of the Hepatitis B Vaccination Programme in Medical Students in a Dutch University Hospital

Healthcare workers (HCW) are at increased risk of contracting hepatitis B virus (HBV) and are, therefore, vaccinated pre-exposure. In this study, the HBV vaccination programme for medical students in a university hospital in the Netherlands was evaluated. In the first part, the effectiveness of the programme, which consisted of a vaccination with Engerix-B^® at 0, 1, and 6 months, was retrospectively evaluated over 7 years (2012-2019). In the second part of this study, we followed students (the 2019 cohort) who had previously been vaccinated against HBV vaccination (4-262 months prior to primary presentation) in order to investigate the most efficient strategy to obtain an adequate anti hepatitis B surface antigen titre. In the latter, titre determination was performed directly during primary presentation instead of giving previously vaccinated students a booster vaccination first. The vaccination programme, as evaluated in the retrospective first part of the study, was effective (surpassed the protection limit of 10 IU/L) in 98.8 percent of the students (95% CI (98.4-99.2)). In the second part of our study, we found that 80 percent (95% CI (70-87)) of the students who had previously been vaccinated against HBV were still sufficiently protected and did not require a booster vaccination. With this strategy, the previously vaccinated students needed an average of 1.4 appointments instead of the 2 appointments needed with the former strategy. This knowledge is important and can save time and resources in the process of occupational HBV vaccination of HCW.

Are healthcare workers immunized after receiving hepatitis B vaccination according to recommended guidelines? A systematic review and meta-analysis

OBJECTIVES

Nowadays, it is believed that more than 240 million people worldwide are infected with the hepatitis B virus (HBV), associated with irreversible health-related consequences, represented by hepatic failure, cirrhosis, and hepatocellular carcinoma, and already are ranked as 15^th cause of human death around the world.

METHODS

A systematic review and a meta-analysis were performed to evaluate the effectiveness of vaccination and immunization on health professionals against HBV. The review was registered at the PROSPERO database (CRD42017075643). A search for cross-sectional studies was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and in the gray literature. The Effective Public Health Practice Project Modified Scale was used to evaluate the internal quality of the studies included.

RESULTS

A total of 1865 articles were identified after the removal of duplicates. Of these, 790 studies remained after screening the titles and abstracts. Finally, ten studies remained after full-text reading for qualitative analysis, all of which were used in the meta-analysis. A significant difference was found in the vaccine protocol for health professionals immunized against hepatitis B, compared to those not immunized. The risk ratio was 7.37 (95% confidence interval = 3.92-13.83; P < 0.00001).

CONCLUSION

This study showed that the vaccine protocol is effective in immunizing health professionals against hepatitis B.

Variable anti-HBs antibody titers in vaccinated birth cohorts - A cross-sectional population-based study

BACKGROUND

After the introduction of hepatitis B (HB) vaccination in 1995 in newborns, two catch-up campaigns targeted unvaccinated 9 year old in 2000-2003 (born 1991-1994) and the 18 year old in 2004-2008 (born 1986-1990), resulting in several birth-cohorts. Our objective was to assess the anti-HBs titers in each birth-cohort.

METHODS

We included all outpatients (78.5%) and hospitalized patients with measured anti-HBs antibody titers in the Teaching Hospital of Infectious Diseases, Cluj-Napoca, Romania, during April 2014 - December 2018 (without HB history). We compared the anti-HBs titers in all birth-cohorts using the Lexis surfaces (titers by age, time period and cohort patterns). We also evaluated the number of acute HB in the corresponding inpatient birth-cohorts and special groups.

RESULTS

We included 2963 participants, mean age = 31.0 ± 14.2, 64.1% women. The birth-cohort 1995-2006, vaccinated after delivery (n = 424, 3-dose HB vaccine coverage > 90%), had significantly lower protective titers (41.3% >10 mIU/mL) compared to the other birth-cohorts: born after 2007 (also vaccinated at birth, 67.0%, n = 106), 1991-1994 (age 9, 74.3%, n = 847), 1986-1990 (age 18, 71.3%, n = 543). In the unvaccinated cohort (n = 1043, mean age = 45.5 ± 12.4) protective titers were found in 44.8%, probably after self-limited HB infection. Concordant results were found using the proportion of patients with detectable or robust titers, and median or geometric mean titers. Four breakthrough acute HB infections were hospitalized of the corresponding vaccinated cohorts (birth years 1988, 1990, 1995, 1996). Data on a few tested infants (n = 47, not included in the main study) demonstrated good protection, 88.9%.

CONCLUSIONS

Our study demonstrated the long-term evidence of protection of HBV vaccine at two decades following the primary immunization and a booster seems unsupported. Further studies should be done to assess the need of a booster dose within the general population and special groups.

Chronic Hepatitis B Prevalence Among Foreign-Born and U.S.-Born Adults in the United States, 1999-2016

Hepatitis B virus (HBV) infection remains a major global health problem, exacerbated by poor linkage to care. We aimed to determine the prevalence of HBV infection, exposure, self-reported vaccination, vaccine-induced immunity, disease awareness, and treatment in the United States by birthplace and race/ethnicity during 1999-2016. A total of 47,628 adult participants in the National Health and Nutrition Examination Survey who completed HBV core antibody (anti-HBc) and surface antigen (HBsAg) tests and 47,618 adults who completed HBV surface antibody (anti-HBs) and anti-HBc tests were included in the analysis. HBV infection was defined by positive HBsAg and past exposure by positive anti-HBc. Vaccine-mediated immunity was defined by positive anti-HBs and negative anti-HBc. No significant change in the prevalence of HBV infection was observed between 1999 and 2016 (P = 0.442), affecting 0.35% (95% confidence interval [CI], 0.28-0.45) or 0.84 million adults. In contrast, a significant decrease in HBV exposure and increase in vaccine-mediated immunity was observed. U.S.-born persons had significantly lower prevalence of HBV infection and exposure as well as higher prevalence of vaccine-mediated immunity and self-reported vaccination than foreign-born persons. Prevalence of HBV infection was highest in non-Hispanic Asians in both foreign- (3.85%; 95% CI, 2.97-4.97) and U.S.-born (0.79%; 95% CI, 0.17-3.59) persons during 2011-2016. Among infected persons, liver disease awareness was only 15.19%, and treatment rate was only 4.60%. Conclusion: This study revealed disparities of HBV infection among ethnic/racial groups and between U.S.-born and foreign-born persons. Awareness of liver disease and treatment rate among infected persons was dismal.

High chance to overcome the non-responder status to hepatitis B vaccine after a further full vaccination course: results from the extended study on healthcare students and workers in Florence, Italy

Healthcare workers (HCWs) are considered high-risk subjects for Hepatitis B Virus (HBV) infection due to occupational exposure to blood and body fluids. Vaccination represents the core strategy for HBV infection prevention. Following our previous publication on this topic, we aimed to assess the effectiveness of booster vaccine doses in eliciting the immunological response in seronegative (<10 mIU/mL) HCWs and students of Careggi Teaching Hospital, Florence (Italy). All subjects received primary vaccination course, and they were tested for serum anti-HBs antibodies. In seronegative subjects, a challenge dose of vaccine was administered and the test was repeated 1 month later. Six hundred and ninety-eight (87.8%) of 795 HCWs and students tested responded to the challenge dose. After this challenge dose, males more often had negative anti-HBs titer compared with females (15.9% vs 10.2%; p < .05). The completion of the second vaccination course was offered to subjects with persistently negative anti-HBs titer. 76.2% (32) of those who accepted the fifth dose, and 3 of the 5 who accepted the sixth dose seroconverted. This report shows the importance to convey a strong message to negative subjects at the initial anti-HBs dosage: accepting all the three additional vaccine doses allows the vast majority of them to obtain protection.

Serum levels of anti-hepatitis B surface antibodies among vaccinated children aged 1 to 12 years in a rural community in Fars Province, southern Iran

The present study aimed to find out the levels of anti-HBsAb among vaccinated children in a rural community in Fars Province, Southern Iran. Blood samples were taken from 550 children, aged 1-12 years (mean 6.4 ± 3.5), in 2017 from three villages in the area. A structured questionnaire was used to get the sociodemographic data of the subjects along with determinants concerning the Hepatitis B. Sera samples were examined for anti-HBsAb, using an ELISA commercial kit. Anti-HBsAb were detected in 468 (85.1%) of the subjects. Of the seropositive subjects, 37 (45.1%) were female and 45 (54.9%) were male. In the age group of 0-5 years, 88.7% of the subjects were seropositive. This rate was 84.3% and 78.1% in the age group of 6-10 years old and older than 10 years, respectively. There was a significant association (p < .05) between the anti-HBsAb and age. Findings of the current study revealed that children living in a rural community in southern Iran have appropriate protection against HBV even more than 10 years after being vaccinated. The decline in seropositivity rate of anti-HBsAb with age may further point out the need for a booster dose of HBV vaccine.

Vaccines for Health Care Personnel

Medical Center Occupational Health (MCOH) programs must protect health care personnel (HCP) against the occupational risk of vaccine-preventable diseases. This thematic review outlines the rationale for the use of recommended vaccines in HCP; summarizes the available evidence regarding vaccine effectiveness, administration, and assessment of immunity; and provides guidance for MCOH programs navigating challenging situations.

Serological Changes against Hepatitis B Surface Antigen in Children and Adolescents Receiving Chemotherapy for Acute Leukemia

BACKGROUND

Vaccination for hepatitis B virus (HBV) after chemotherapy among pediatric patients with acute Leukemia is still a debated issue. We investigated HBV immunity before and after chemotherapy and assessed immune response to re-vaccination after chemotherapy.

METHODS

We retrospectively analyzed data of children and adolescents aged <19 years requested for vaccination after chemotherapy for acute leukemia to evaluate hepatitis B surface antibody (HBsAb) status before and after chemotherapy and to identify factors related to HBsAb positivity after chemotherapy.

RESULTS

Of 89 enrolled patients, 61 (68.5%) with acute leukemia were HBsAb positive before chemotherapy. Of these 61 patients, 48 (78.7%) seroconverted to HBsAb negative status after chemotherapy; there were 76 (85.4%) HBsAb negative patients after chemotherapy. HBsAb positive patients when compared to HBsAb negative patients after chemotherapy had a significantly higher HBsAb positive rate (100.0% vs. 63.2%, p=0.008) before chemotherapy. Following HBsAb testing after one dose of the HBV vaccination, 33 (43.4%) of the 76 HBsAb negative patients seroconverted to an HBsAb positive status. HBsAb positive patients after a single dose of HBV vaccination had a significantly higher HBsAb positive rate at the time of diagnosis compared to HBsAb negative patients (84.8% vs. 48.8%, p=0.001).

CONCLUSIONS

Based on these results, HBV re-vaccination after chemotherapy is recommended for all children and adolescents with acute leukemia. In addition, further investigation is required to improve the immunogenicity of HBV re-vaccination.

Long-term protection at 20-31 years after primary vaccination with plasma-derived hepatitis B vaccine in a Chinese rural community

Background: To assess the long-term protection conferred by plasma-derived hepatitis B vaccine at 20-31y after primary immunization during infancy in Chinese rural community.Method: Participants born between 1986 and 1996, who received a full course of primary vaccination with plasma-derived hepatitis B vaccine and had no experience with booster vaccination were enrolled. An epidemiological investigation was performed, and blood samples were collected to detect hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc). The positive rate of HBsAg, anti-HBs, and anti-HBc were calculated to evaluate the long-term protection of the plasma-derived hepatitis B vaccine.Results: A total of 949 participants were enrolled in the final analysis. Six subjects were detected to be HBsAg-positive, resulting in a HBsAg carrier rate of 0.63% (6/949). A total of 468 (52.41%) participants maintained a level of anti-HBs antibody ≥10 mIU/mL, with a GMC of 112.20 mIU/mL (95%CI: 97.72 ~ 128.82 mIU/mL). A significant downtrend was observed in the anti-HBs positive rate (P < .001). The average anti-HBc positive rate was 5.90% (56/949), increased with prolongation of immunization (P < .001).Conclusions: The plasma-derived hepatitis B vaccine maintained satisfactory protection at 20-31 y after primary immunization. These results indicate that a booster dose is not necessary. Further studies on the immune memory induced by the plasma-derived hepatitis B vaccine are needed.

Hepatitis B sero-prevalence in children under 15 years of age in South Africa using residual samples from community-based febrile rash surveillance

Introduction and methods

Hepatitis B is a vaccine preventable disease and is notifiable in South Africa. Hepatitis B vaccination was incorporated into the Expanded Programme on Immunisation in South Africa in 1995. We used a convenience sample from community-based febrile rash surveillance in 2013 to estimate hepatitis B sero-prevalence. Of samples serologically negative for acute measles infection, 450 samples spanning nine provinces of South Africa were tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc).

Results

Two children (2/450; 0.4%) tested positive for HBsAg. Three hundred and three children (67.3%) had evidence of vaccine induced immunity. Vaccine induced immunity was present in 80.2% of 1–5 year olds, but only 60.3% of 10–14 year olds. Natural immunity, indicating exposure to circulating hepatitis B, was present in 13/450 (2.9%) children.

Conclusion

Chronic hepatitis B in South African has decreased in prevalence from highly endemic levels prior to vaccine introduction to approximately 0.4% in this sample, demonstrating impact of a successful vaccination programme 18 years after introduction. Decreased vaccine-induced immunity with increasing age may reflect waning antibody titres over time.

Immune persistence 17 to 20 years after primary vaccination with recombination hepatitis B vaccine (CHO) and the effect of booster dose vaccination

BACKGROUND

To assess the immune persistence conferred by a Chinese hamster ovary (CHO)-derived hepatitis B vaccine (HepB) 17 to 20 years after primary immunization during early life.

METHODS

Participants born between 1997 and 1999 who received a full course of primary vaccination with HepB (CHO) and who had no experience with booster vaccination were enrolled. Blood samples were required from each participant for measurement of hepatitis B surface antibody (anti-HBs), surface antigen and core antibody levels. For those who possessed an anti-HBs antibody < 10 mIU/mL, a single dose of HepB was administered, and 30 days later, serum specimens were collected to assess the booster effects.

RESULTS

A total of 1352 participants were included in this study. Of these, 1007 (74.5%) participants could retain an anti-HBs antibody ≥10 mIU/mL, with a geometric mean concentration (GMC) of 57.4 mIU/mL. HBsAg was detected in six participants, resulting in a HBsAg carrier rate of 0.4% (6/1352). Of those participants with anti-HBs antibodies < 10 mIU/mL, after a challenge dose, 231 (93.1%) presented an anti-HBs antibody ≥10 mIU/mL, with a GMC of 368.7 mIU/mL. A significant increase in the anti-HBs positive rate (≥ 10 mIU/mL) after challenge was observed in participants with anti-HBs antibodies between 2.5 and 10 mIU/mL and participants boosted with HepB (CHO), rather than those with anti-HBs antibodies < 2.5 mIU/mL and those boosted with HepB (SC).

CONCLUSION

Since satisfactory immune protection against HBV infection conferred by primary vaccination administered 17-20 years ago was demonstrated, there is currently no urgent need for booster immunization.

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.

Persistence of Immunity for Hepatitis B Virus among Heathcare Workers and Italian Medical Students 20 Years after Vaccination

Background: Immunization of healthcare workers (HCWs) and medical students for the hepatitis B virus (HBV) is a crucial part of the hospital infection control programs. The aim of our study was to evaluate the persistence of anti-HBV specific antibodies in HCWs vaccinated during infancy or adolescence. Methods: Medical records of 734 consecutive subjects born after 1980 (481 females, 65.5% and 253 males, 34.5%) who underwent serological testing for anti-hepatitis B surface antibodies (anti-HBs) were evaluated. Results: A non-protective titer (<10 mUI) was found in 88/734 (12.0%) subjects; 84 (47.8%) of them received a booster dose of anti-hepatitis B vaccine and the anti-HBs titer of 58 subjects was measured 1 month after administration. A protective titer (anti-HBs >10 mIU/mL) was observed in almost 90% of subjects receiving the booster dose. Conclusions: A substantial percentage of HCWs had a non-protective anti-HBs titer at the time of the first employment, especially those vaccinated at birth age. However, the response to the booster dose showed that in these subjects, an anti-HBs titer <10 mIU/mL was due to the physiological decline of antibodies over the years. Therefore, primary immunization in childhood is highly effective and provides lasting immunity against HBV infection.

Risk of Hepatitis B Reactivation in Patients with Psoriasis on Ustekinumab

BACKGROUND AND OBJECTIVES

Ustekinumab is used to treat moderate-to-severe psoriasis by blocking the interleukin-12/23 pathway, which is also essential against intracellular pathogens. Because there is a high prevalence of hepatitis B viral infection in Taiwan, the expected risk of reactivation is higher among ustekinumab-treated patients. We performed this study to investigate the risk of hepatitis reactivation.

SUBJECTS AND METHODS

Patients with psoriasis treated with ustekinumab from October 2011 to June 2016 were enrolled in a prospective cohort study. All patients were tested for hepatitis B serology and serum viral DNA at baseline. For those positive for hepatitis B surface antigen (HBsAg) or hepatitis B core antibodies (anti-HBc) testing for HBV DNA was conducted at least annually. An increase of HBV DNA > 2 log scale or emergence of HBV DNA were defined as reactivation. The primary outcome of this study was HBV reactivation.

RESULTS

Ninety-three psoriasis patients receiving ustekinumab were included. The average duration of treatment and follow-up was 24 ± 12 months. There were 39 patients classified as naïve to HBV or vaccinated, and none of these patients had HBV reactivation. Among the remaining 54 patients classified as inactive HBV carriers, resolved HBV infection, or isolated anti-HBc positivity, only 3 patients experienced virologic reactivation, and none had liver failure.

CONCLUSION

The study outcomes indicate that ustekinumab could be safe for psoriasis patients since none developed persistent hepatitis or acute liver failure during therapy. However, the re-appearance of plasma HBV DNA requires appropriate monitoring of HBV viral load during ustekinumab treatment.

Persistence of immune memory among adults with normal and high antibody response to primary hepatitis B vaccination: Results from a five-year follow-up study in China

Immune memory after hepatitis B vaccination among adults is still under investigation. In this study, adults who had normal and high antibody response to the primary series of hepatitis B vaccination (HepB) were followed up at 5 years after the primary immunization. A booster dose was given to those who had low hepatitis B surface antibody (anti-HBs) titers, defined as anti-HBs levels < 10 mIU/mL. Blood samples were collected at two weeks after the booster and anti-HBs levels were measured. We assumed those with ant-HBs levels > = 10 mIU/mL after the booster had anamnestic response. In total, 242 persons completed the booster and the anti-HBs test. The anamnestic response rate was 99.59% (241/242) and geometric mean concentration (GMC) of anti-HBs after the booster was 2989 mIU/mL (95% CI: 255, 35085). Anti-HBs titer after the booster dose had a positive correlation with anti-HBs titers measured right after the primary immunization as well as anti-HBs titers 5 years later just before the booster. After the booster, no significant difference was found in anti-HBs titers between participants who were immunized with the 10μg HepB vaccine and those with the 20μg vaccine. Multivariable analysis showed that 1) vaccine brand used for the primary vaccination, 2) anti-HBs titers after primary vaccination and 3) anti-HBs titers before the booster dose were independently associated with the anti-HBs titers after the booster 1) β = -0.21, 95% CI: -0.33, -0.09, P = 0.001; 2) β = 0.07, 95% CI: 0.05, 0.09, P < 0.001; 3) β = 0.04, 95% CI: 0.02, 0.07, P < 0.001). In summary, anamnestic response exists among almost all adults at five years after HepB primary immunization. Vaccine brand used for primary vaccination, initial anti-HBs titers after primary immunization and anti-HBs titers before the booster were the independent predictive factors of HepB anamnestic response titers.

Revaccination against hepatitis B in late teenagers who received vaccination during infancy: Yes or no?

The significance of vaccination against hepatitis B during infancy is recognized worldwide, however, whether booster or revaccination after a period of time following the primary vaccination is required remains controversial. Recently, cross-sectional epidemiological surveys found that HBsAg prevalence in subjects born after the implementation of mass vaccination was increased with age, which was attributed to waning of anti-HBs over time. However, comprehensive analysis of the closely related cross-sectional surveys showed that the age-specific increased HBsAg prevalence was more likely associated with the carry-over of the infection occurred in early life, likely due to imperfect coverage of hepatitis B vaccination at the beginning of its introduction. Latest studies showed that booster response could be observed in the majority of individuals vaccinated 30 years ago. Moreover, confirmed breakthrough HBV infection with severe consequences in successfully vaccinated individuals is extremely rare. Thus far no compelling evidence has been acquired to support booster vaccination in adolescence. The uncertainty regarding the duration of protection of hepatitis B vaccination, especially beyond 30 years after the primary vaccination, merits a systematically designed study to follow the same cohort of participants longitudinally, which differs from the cross-sectional studies reported previously, can hopefully offer more direct evidence to help us to determine whether revaccination of hepatitis B vaccine is necessary.

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

We determined the prevalence of anti-hepatitis B surface antibodies (anti-HBs) among children and adolescents vaccinated for hepatitis B virus in infancy as part of the routine vaccination programme. A representative serum sample of the Israeli population age 0-19 was tested. In a separate pilot study, a booster dose of hepatitis B vaccine was administered to 31 candidates for national service, who were fully vaccinated in infancy and tested negative for hepatitis B surface antibodies at age 17-19 years and anti-HBs antibodies were assessed 8 weeks later. Of the 1273 samples tested, 631 (49·6%) were positive to anti-HBs antibodies. Seropositivity rates were 89·5% among infants aged 6-12 months and declined significantly with age to 20·7% at age 19 years. No differences in seropositivity rates were observed between Jews and Arabs, males and females and those born in Israel and in other countries. Seroconversion rate among the 31 individuals who received a booster dose was 90·3% (95% CI: 75·1-96·6%). We recommend a booster dose for healthcare personnel before starting to work at the health care facility.

The declining rates of hepatitis B carriage among adolescents and young people in the Eastern region of Saudi Arabia

Objectives:

To study age specific rates of hepatitis B virus (HBV) carriage in the eastern region of Saudi Arabia following a 24 year immunization program.

Methods:

Hepatitis B surveillance data between January 2004 and December 2013 were analyzed in a retrospective study, which included 24,504,914 patients. Seropositive cases of hepatitis B were reported by laboratory personnel as part of various investigations. Hepatitis B cases including acute and chronic carriers were identified upon serological positivity of hepatitis B surface antigen (HBsAg).

Results:

The study shows that the overall prevalence rate decreased from 18.8 to 9.9/100,000 population between 2004 and 2013 (p=0.01). It was also found that the prevalence rate increased with age. For instance, the highest prevalence of hepatitis B was seen among patients >15 years of age and the lowest was seen among children <15 years of age. Over the period, the prevalence rate decreased in all age groups with the greatest decline among the age groups <4 years old. However, this was statistically insignificant (p>0.05). Another significant reduction in the prevalence rate occurred among age groups 5-14 years old (p=0.00). An insignificant decrease in the rate by 43% was also seen among older patients of 15-44 years old and 35% in >45 years old. The overall prevalence of hepatitis B is significantly higher in men than in women (p=0.00).

Conclusion:

There is a particular decreased trend in the prevalence of HBV infection in different age groups over a decade of surveillance following more than 20 years of the universal HBV vaccination program.

The association of the vitamin D status with the persistence of anti-HBs antibody at 20years after primary vaccination with recombinant hepatitis B vaccine in infancy

BACKGROUND AND OBJECTIVE

Vitamin D has potent immunoregulatory effects due to the expression of its receptor on the majority of immune cells. The aim was to evaluate the association of the vitamin D status with the persistence of anti-HBs antibody and immune response to booster immunization at 20years after primary vaccination with hepatitis B (HB) vaccine.

METHODS

Blood samples were collected from 300 adults 20years after completion of the primary HB vaccination in infancy. The serum levels of vitamin D and anti-HBs antibody were measured by ELISA. A single booster dose of a recombinant HB vaccine was administered to a total of 138 subjects, whose anti-HBs titer was<10IU/L. The sera of revaccinated subjects were re-tested for anti-HBs antibody, 4weeks after booster vaccination.

RESULTS

At 20years after primary vaccination, the mean vitamin D concentrations were significantly higher in seroprotective subjects as compared to non-seroprotective individuals (P<0.01). The levels of anti-HBs were significantly increased with advanced concentrations of vitamin D (P<0.01). Overall, 125/138 (90.6%) of the revaccinated subjects showed an anamnestic response to booster vaccination. The concentrations of vitamin D were significantly higher in subjects with an anamnestic response to booster vaccination as compared with subjects without this response (P<0.01).

CONCLUSION

Vitamin D status may influence the persistence of anti-HBs antibody and durability of protection after primary vaccination with a recombinant HB vaccine in infancy.

Long-term effectiveness of plasma-derived hepatitis B vaccine 22-28 years after immunization in a hepatitis B virus endemic rural area: is an adult booster dose needed?

Longan County is considered a highly endemic area for hepatitis B virus (HBV). The plasma-derived vaccine has been used in newborns in this area since 1987. A cross-sectional survey was conducted to evaluate the long-term effectiveness of this vaccine. In total, 1634 participants born during 1987-1993 and who had received a series of plasma-derived HB vaccinations at ages 0, 1, and 6 months were enrolled. Serological HBV markers were detected and compared with previous survey data. Overall the prevalence of hepatitis B surface antigen (HBsAg) in all participants was 3·79%; 3·47% of subjects who had received the first dose within 24 h were HBsAg positive, and 8·41% of subjects who had received a delayed first dose were also HBsAg positive. There were 1527 subjects identified who had received the first dose within 24 h and whose HBsAg and anti-HBc prevalence increased yearly after immunization, while the anti-HBs-positive rate and vaccine effectiveness declined. The geometric mean concentration of antibody in the anti-HB-positive participants was 55·13 mIU/ml and this declined after immunization. Fewer than 2·0% of participants had anti-HB levels ⩾1000 mIU/ml. The data show that the protective efficacy of the plasma-derived vaccinations declined and administration of HB vaccine within 24 h of birth was very important. To reduce the risk of HBV infection in this highly endemic area, a booster dose might be necessary if anti-HBs levels fall below 10 mIU/ml after age 18 years. Furthermore, studies on the immune memory induced by plasma-derived HB vaccine are needed.

Prevalence of hepatitis B surface antigen (HBsAg) in a blood donor population born prior to and after implementation of universal HBV vaccination in Shenzhen, China

Background

Neonatal hepatitis B vaccination program at birth has been implemented nationwide since 1992 in China. However, current HBV prevalence status in blood donors has not been entirely examined, which may impact HBV safety in blood donations as the vaccinees over 18 years old progressively become the majority population of blood donors.

Methods

In this study, 569,145 blood donors were screened for HBsAg by rapid tests and enzyme immunoassays, among them 475,538 blood samples with negative HBsAg were further screened for HBV DNA by nucleic acid testing between 2005 and 2014 at Shenzhen blood center.

Results

An overall 2.3 % HBsAg prevalence was found in the blood donor population during the past 10 years (2.86 % in 2005, 1.76 % in 2010, and 2.79 % in 2014, respectively). HBsAg seroconversion occurred in 0.37 % of repeat-donors. When stratified by age, the prevalence of HBsAg was found significantly higher in younger donors age 18–25 years (2.73 %) than in those 26–35 years (2.13 %), 36–45 years (2.03 %) and 46–58 years (1.71 %) (P < 0.001), unexpectedly suggesting that younger donors remained at risk of chronic HBV infection. Assuming that donors aged 18–22 born before or after 1992 were non-vaccinated and vaccinated, respectively, HBsAg prevalence was higher in first-time donors born ≥1992 (3.9 %) than prior to 1992 (3.5 %, P = 0.005). The incidence of HBV infection in the 5-year period examined was significantly lower in repeat-donors born ≥1992 (0.27 %) than prior to 1992 (0.6 %, P = 0.008). The yield of HBV DNA+/HBsAg- donors was 1:3,302, including 1:4,486 occult infections and 1:43,231 window period infections.

Conclusion

Young blood donors born after implementation of universal HBV vaccination in China presented higher prevalence of HBsAg but lower incidence of HBsAg seroconversion than older, presumed unvaccinated, donors. HBV vaccine boosting for adolescents at 15–17 years old prior to reaching blood donor age might help improve blood safety.

Impact and long-term protection of hepatitis B vaccination: 17 years after universal hepatitis B vaccination in Tunisia

Hepatitis B virus (HBV) vaccination has been part of the Expanded Programme of Immunization (EPI) in Tunisia since 1995. The aim of this study was to evaluate, for the first time, the impact of mass vaccination in Tunisia 17 years after this programme was implemented, and in parallel, assess the long-term persistence of anti-HBs antibody in the vaccinated Tunisian population. A total of 1422 students were recruited (703 vaccinated, 719 non-vaccinated). HBV seromarkers were checked. None of the students from either group had positive HBsAg. The overall prevalence of anti-HBc was 0·8%. A Significantly higher prevalence of anti-HBc was noted in unvaccinated students than in vaccinated (1·4% vs. 0·3%, P = 0·02). The overall seroprotection rate (anti-HBs titre ⩾10 mIU/ml) was 68·9% in vaccinated subjects. Seroprotection rates and geometric mean titres decreased significantly with increasing age, reflecting waning anti-HBs titre over time. No significant difference was detected between seroprotection rates and gender or students' area of origin. Incomplete vaccination was the only factor associated with an anti-HBs titre <10 mIU/ml. This study demonstrates the excellent efficacy of the HBV vaccination programme in Tunisia 17 years after its launch. However, a significant decline of anti-HBs seroprotection has been observed in ⩾15-year-old adolescents which places them at risk of infection. Additional studies are needed in hyperendemic regions in Tunisia.

Hepatitis B surface antibodies in medical students from a public university in Puebla, Mexico

Although preventable with vaccination, Hepatitis B virus (HBV) infection is a major health concern, with ∼400 million people at risk of developing the chronic form of the disease worldwide. The anti-HBV vaccine consists of a recombinant HBV surface antigen (HBsAg), which induces specific anti-HBs antibodies and confers 95% protection for >20 y. The aim of the present study was to analyze the response to HBV vaccination by measuring anti-HBs antibodies in serum samples from medical students of a public university in Puebla, Mexico. HBV infection markers HBsAg and anti-HBs, were also determined. A total of 201 students were included and vaccination coverage was found at 54%. Overall seropositivity for HBsAg, anti-HBc and anti-HBs determined by ELISA was 0.5%, 1.0% and 47%, respectively. Protective levels of anti-HBs >10 mIU/mL were found in 93.2% of subjects vaccinated with 2 or 3 doses and in 40% of those vaccinated with a single dose; while only 4.8% of unvaccinated subjects were anti-HBs positive. The response to the HBV vaccine was different in each participant, despite similar vaccination scheme. A history of blood transfusion/organ transplant or more than 2 sexual partners was significantly associated with anti-HBc positivity, OR = 399 (p = 0.010) and OR = 19.9 (p = 0.044), respectively. HBV immunization coverage was low in our sample compared with reports from countries with similar HBV prevalence, but anti-HBs in vaccinated individuals were in the expected range. It is important to promote HBV vaccination and awareness among medical students, due to their exposure risk.

Immunity to hepatitis A and B persists for at least 15 years after immunisation of adolescents with a combined hepatitis A and B vaccine

BACKGROUND

The exact duration of antibody persistence to hepatitis A and B and the need for booster dosing following primary immunisation remains undefined. A long-term study was designed to follow antibody persistence and immune memory on an annual basis for up to 15 years following vaccination during adolescence.

METHODS

Subjects received a combined hepatitis A and B vaccine (Twinrix™, GSK Vaccines, Belgium) at 12-15 years of age, either as 2-dose of the adult formulation or 3-dose of the paediatric formulation. Blood samples were taken every year thereafter to assess antibody persistence and immune memory to hepatitis A and B. Antibodies to hepatitis A virus (anti-HAV) and hepatitis B surface antigen (anti-HBs) were measured at Years 11-15. At Year 15 immune memory was further assessed by measuring the anamnestic response to a challenge dose of the monovalent vaccine, which was administered to subjects whose antibody concentrations fell below the pre-defined cut-offs (anti-HAV: <15mIU/mL; anti-HBs: <10mIU/mL).

RESULTS

209 subjects returned for follow-up at Year 15 of whom 162 were included in the long-term according-to-protocol immunogenicity cohort. All subjects remained seropositive for anti-HAV antibodies, while 81.1% and 81.8% still had anti-HBs antibodies ≥10mIU/mL in the 2- and 3-dose groups, respectively. Following hepatitis B vaccine challenge dose administration to 19 subjects, all except one in the 3-dose group, mounted a robust anamnestic response. The safety and reactogenicity profile of the hepatitis B challenge was consistent with previous experience.

CONCLUSION

Immunity to hepatitis A and B persists 15 years after adolescent vaccination with a combined hepatitis A and B vaccine. Highly effective anamnestic response indicates that a booster dose should not be required for 15 years after primary vaccination.

TRIAL REGISTRATION

http://www.clinicaltrials.govNCT00875485.