Antibody persistence and the effect of a booster dose given 5, 10 or 15 years after vaccinating preadolescents with a recombinant hepatitis B vaccine

Protection and antibody levels 35 years after primary series with hepatitis B vaccine and response to a booster dose

BACKGROUND AND AIMS

The duration of protection from hepatitis B vaccination in children and adults is not known. In 1981, we used three doses of plasma-derived hepatitis B vaccine to immunize a cohort of 1578 Alaska Native adults and children from 15 Alaska communities who were ≥6 months old.

APPROACH AND RESULTS

We tested persons for antibody to hepatitis B surface antigen (anti-HBs) levels 35 years after receiving the primary series. Those with levels <10 mIU/ml received one booster dose of recombinant hepatitis B vaccine 2-4 weeks later and were then evaluated on the basis of anti-HBs measurements 30 days postbooster. Among the 320 recruited, 112 persons had not participated in the 22- or 30-year follow-up study (group 1), and 208 persons had participated but were not given an HBV booster dose (group 2). Among the 112 persons in group 1 who responded to the original primary series, 53 (47.3%) had an anti-HBs level ≥10 mIU/ml. Among group 1, 73.7% (28 of 38) of persons available for a booster dose responded to it with an anti-HBs level ≥10 mIU/ml at 30 days. Initial anti-HBs level after the primary series was correlated with higher anti-HBs levels at 35 years. Among 8 persons who tested positive for antibody to hepatitis B core antigen, none tested positive for HBsAg or HBV DNA.

CONCLUSIONS

Based on anti-HBs level ≥10 mIU/ml at 35 years and a 73.7% booster dose response, we estimate that 86% of participants had evidence of protection 35 years later. Booster doses are not needed in the general population at this time.

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.

Long-term Immunity Against Hepatitis B Virus After Routine Immunization Among Adults Visiting Primary Care Centers in Riyadh, Saudi Arabia

Objective This study aimed to determine the persistence of induced immunity against hepatitis B virus (HBV) among adults routinely vaccinated during their infancy and correlate the level of induced immunity with participant characteristics. Methodology This was a cross-sectional study conducted among visitors to primary care centers of the Ministry of Health (MOH) in Riyadh, the Kingdom of Saudi Arabia (KSA) during the period from August 2020 to January 2021. The study population included healthy adults of both genders who had received full doses of the HBV vaccine in infancy. Data related to participant characteristics were collected using a self-administered questionnaire. A blood sample was then taken from each participant to measure the serum level of hepatitis B surface antigen (HBsAg), antibodies against HBsAg (anti-HBs), and antibodies against hepatitis B core antigen (ani-HBc). Results A total of 400 subjects participated in the study; the mean age of the cohort was 25 years. Almost all of them were Saudis (99.30%), and more than half (57.50%) were males. Only 24.30% had an anti-HBs antibodies level of ≥10 IU/L, and all respondents were negative for HBs antigen. No significant association between participant characteristics and anti-HBs antibody levels was found. Conclusion A decline in immunity many years after HBV vaccinations taken in infancy has been well-documented. However, for low-risk populations, the boosting of HBV vaccines is probably unnecessary since the immune memory provides sufficient protection despite low or undetectable anti-HBs antibodies.

Immune response to hepatitis B vaccine: An evaluation

Background:

Hepatitis B virus infection is a major public health problem in India, and all health-care workers (HCWs) need to be immunized to prevent occupational exposure. This study was done to find the hepatitis B vaccination rates, immune response, and predictors of titer <10 mIU/ml among students and HCWs of a tertiary care institution in the state of Kerala.

Materials and Methods:

This was a cross-sectional study conducted in the Department of Microbiology, Government TD Medical College, Alappuzha, Kerala, India, for a period of 1½ years between January 1, 2016, and June 30, 2017. Vaccination rates were collected through a screening proforma. Of the 1321 participants who filled the screening proforma, 5 ml of blood was collected aseptically from 579 participants who were fully vaccinated (all the three doses of vaccine) and stored at −20°C until antibody to hepatitis B surface antigen (anti-HBs) assay was done using Microlisa (Biorad). Data were analyzed using SPSS for Windows, version 16.0. (SPSS Inc., Chicago, IL, USA) (trial version).

Statistical Analysis:

Descriptive data were expressed using frequencies and percentages, and Chi-square test was applied to find the association between antibody titer <10 mIU/ml and independent variables.

Results:

Of the 1321 participants who filled up the screening proforma, the vaccination rate was 72.6%. Majority of the participants, i.e. 83.5% of doctors, 81.1% of nurses, 69.7% of students, and 21.4% of technicians, had taken all the three doses of hepatitis B vaccine. Of the fully vaccinated (n = 959) participants, 76.9% had the vaccination during adulthood and only 26.1% had it during childhood. The correlate of protection was defined as the presence of anti-HBs ≥10 mIU/ml. The mean antibody titer was 448 ± 284.97 mIU/ml ranging from 9.8 to 2000. Of the 579 participants whose titer was checked, 71 (12.3%) had a nonprotective titer of <10 mIU/ml. We found that age >35 (odds ratio [OR]: 3.85, 95% confidence interval [CI]: 2.12–6.99]), last dose >10 years (OR: 5.01, 95% CI: 2.94–8.55), no boosters or revaccination (OR: 2.94, 95% CI: 1.42–6.07), and body mass index (BMI) >25 (OR: 2.51, 95% CI: 1.44–3.39) were associated with nonprotective titer.

Conclusion:

More than a quarter of the study population who were at high risk of exposure were unvaccinated or partially vaccinated. Even after taking the full course of hepatitis B vaccine, 12.3% had titer <10 mIU/ml. Nonprotective titer was found to be associated with age >35 years, last dose taken >10 years ago, no boosters/revaccination, and BMI ≥25.

"Titer of anti-HBs in health professions trainees: prevalence of antibody coverage in a University of Central Italy"

Objective: This observational retrospective study aims at verifying hepatitis-B-virus (HBV) vaccination coverage in students vaccinated before and after 1992, in order to optimize health surveillance and vaccination recall.Methods: Vaccination status was evaluated using the anti-HBs antibody titer (anti-HBs). Student t-test and the chi-square test were performed to identify the average age and the difference in antibody coverage between the two genders and in the two populations analyzed.Results: Our study outlined a prevalence of 21.83% uncovered trainees among those vaccinated at age 12 and 45.03% among those vaccinated in neonatal age.Conclusion: In conclusion, our data showed persistent protection against HBV infection in healthcare students.

Hepatitis B vaccination in Indian children: Seroprotection and age-related change in antibody titres

Background

Childhood immunization against hepatitis B is one of the most effective strategies for reducing the global burden of chronic hepatitis B infection and its sequelae. There are limited data from India on both the anti-Hep B antibody titres in children after vaccination and the age-related decline in the titres. This study was planned to estimate the proportion of children in the age group of 1-10 years who develop protective levels of anti-hepatitis B antibodies after childhood vaccination and to examine the change in antibody titres with age in these children.

Methods

A hospital-based cross-sectional study was carried out in children admitted to the hospital for various ailments. Basic demographic data, vaccination history and HBsAg status of the mother were recorded. All the enrolled children were evaluated for HBsAg and anti hepatitis B surface antibody (anti-HBS) titres. Institutional ethical clearance was obtained, and informed consent from the parents of the children was taken before drawing samples.

Results

We found that 68.86% Confidence Interval ((CI): 59.8-76.8%) of the children showed protective antibody titres after vaccination, while 31.14% (CI: 23.1-40.2%) of the children had titres less than 10 IU/L. Although 100% of children in the age group from birth to three years had titres more than 10 IU/L, this percentage showed a decline across the age groups, and 60% of children aged 9-10 years had titres less than 10 IU/L.

Conclusion

Childhood vaccination against hepatitis B is effective in 68% children, and the antibody levels showed a steady decline with increasing age.

Evaluation of antibody persistence after a four-dose primary hepatitis B vaccination and anamnestic immune response in children under 6 years

Introduction. Tunisia is an intermediate hepatitis B virus (HBV) endemic country. The vaccination against hepatitis B was introduced in 1995 including four doses with a first dose administrated at birth. Decreasing the level of antibodies against hepatitis B surface antigen (anti-HBs) over time can be alarming. This study was conducted to explore the anti-HBV immune response among children under 6 years old, vaccinated according to the national vaccination schedule, by evaluating the immunological response to primary vaccination and by exploring the anamnestic immune response to a booster dose.Methods. We conducted a cross-sectional prospective study from June 2016 to June 2017 (n=180), based on voluntary participation. Children were recruited from the public pediatric ward sectors in Sahloul University Hospital of Sousse in Central Tunisia. An anti-HB titre was determined based on electro-chemiluminescence micro-particle immunoassay (ECLIA), using Elecsys Anti-HBs II kit, Roche.Results. Mean age at the time of enrollment in the study was 33±14.8 months. The seroprotection rate was 77.2 %. The anti-HB titre differed significantly between the different age groups (P=0.002). The predicting variable for having no seroprotective antibody level was older age. Children with anti-HB levels <10 IU l^{- 1} were offered an additional dose of HBV vaccine. Anamnestic response 1 month after the challenge dose was observed in 100 % of subjects. The probability of developing a high antibody response, following the booster dose increased in conjunction with an increased pre-booster antibody level.Conclusion. The response to a booster dose suggests the persistence of immune memory in almost all vaccinated individuals. Although a booster dose increases substantially anti-HB titre, the clinical relevance of such an increase remains unknown.

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.

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

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

Serologic Status of Routine Childhood Vaccines, Cytomegalovirus, and Epstein-Barr Virus in Children With Inflammatory Bowel Disease

BACKGROUND

Data on the serologic status of childhood vaccines, cytomegalovirus (CMV) and Epstein-Barr virus (EBV), are limited in inflammatory bowel disease (IBD). Therefore, we evaluated vaccine coverage and seroprotection, along with CMV and EBV seropositivity, in pediatric IBD.

METHODS

In a cross-sectional study, demographic data, IBD history, vaccine records, and serum for antibodies against measles, mumps, rubella, diphtheria, tetanus, varicella, hepatitis B (HBV), CMV, and EBV were collected from children with IBD. We evaluated potential factors associated with serologic status.

RESULTS

Of 156 subjects, vaccine coverage was up to date for age in 93.5% for measles, mumps, rubella, 95.6% for diphtheria, tetanus, pertussis, polio, hemophilus influenza B, 75.8% for HBV, and 93.5% for varicella, including past infection and vaccination. Seroprotection was present in 65.8% for measles, 60.5% for mumps, 79.1% for rubella, 79.5% for diphtheria, 80.8% for tetanus, 70.5% for varicella, and 62.8% for HBV of subjects. Older age at diagnosis was associated with seroprotection among subjects with complete HBV (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.03-1.39) and rubella series (OR, 1.18; 95% CI, 1.02-1.37). Older age at serum collection was associated with seroprotection among subjects with prior varicella vaccination or infection (OR, 1.69; 95% CI, 1.33-2.15). Only 25.2% and 37.8% demonstrated seropositivity to CMV and EBV, respectively. Among subjects on immunosuppressive medications, 75.3% and 62.4% were seronegative for CMV and EBV, respectively.

CONCLUSIONS

Children with IBD have low serologic protection to childhood vaccines in spite of high vaccine coverage and universal vaccinations. Children with IBD, including a large proportion on immunosuppressive medications, have low seropositivity to CMV and EBV.

Will Infant Hepatitis B Immunization Protect Adults?

Globally, infant hepatitis B virus (HBV) immunization programs are markedly reducing the rate of chronic HBV infections among children <5 years of age. Desirable improvements include increased birth dose coverage and better prevention of perinatal HBV transmission. Follow-up studies show that by the teenage years most of those immunized as infants have lost circulating anti-HBs antibody and some fail to respond to challenge HBV vaccination, implying loss of protection from infection. With high exposure to HBV, such individuals can develop breakthrough HBV infection but this rarely leads to chronic infection, the main goal of prevention programs. While longer-term follow-up studies into adulthood are needed, current evidence does not support a need for booster immunization of otherwise healthy teens or young adults.

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.

Persistence of hepatitis B immune memory until 9-10 years of age following hepatitis B vaccination at birth and DTaP-IPV-HB-PRP∼T vaccination at 2, 4 and 6 months

OBJECTIVE

To evaluate the long-term persistence of anti-hepatitis B surface (HBs) antibodies and the response to a HB challenge re-vaccination in children who had received a primary series of DTaP-IPV-HB-PRP∼T (Hexaxim™) or DTaP-IPV-HB/PRP∼T (Infanrix hexa™).

METHODS

Two cohorts of participants who had previously received HB vaccine at birth followed by either DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T co-administered with PCV7 at 2, 4, 6 months of age in a randomized, Phase III, observer-blind study in Thailand, were followed up for anti-HBs antibodies (geometric mean concentrations [GMCs] and seroprotection [SP] rate [% of participants with a titer ≥10 mIU/mL]) at 12-18 months of age and 9-10 years of age. A monovalent HB challenge re-vaccination was administered at 9-10 years of age and the anamnestic response was evaluated.

RESULTS

Anti-HBs GMCs and SP rates in the DTaP-IPV-HB-PRP∼T and DTaP-IPV-HB/PRP∼T groups were high and similar post-primary vaccination series (2477 mIU/mL and 99.5% and 2442 mIU/mL and 99.5%, respectively) and declined to a similar extent in each group at 12-18 months (154.5 mIU/mL and 90.8% and 162.3 mIU/mL and 96.5%, respectively). Antibody levels further declined at 9-10 years of age (13.3 mIU/mL and 49.3% and 8.0 mIU/mL and 42.9%) and a strong anamnestic response occurred in each group post-HB challenge re-vaccination (92.8% and 98.7%, respectively).

CONCLUSION

The kinetics of long-term anti-HBs antibody persistence were similar following a primary series of DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T. The response to a subsequent HB challenge re-vaccination was strong and similar in each group, demonstrating persisting immune memory.

Incidence of Low Seroimmunity to Hepatitis B Virus in Children With Inflammatory Bowel Disease

OBJECTIVES

Patients with inflammatory bowel disease (IBD) often receive immunosuppressive therapy, which may make them vulnerable to infections such as hepatitis B. We hypothesized that hepatitis B virus titers are low in the vaccinated pediatric population with IBD. The aims of our study were to identify the incidence of lower titers of hepatitis B surface antibody (HBsAb) and determine which patient factors may be associated with lower HBsAb titers.

METHODS

Patients with diagnosis of IBD, ages 5 to 18 years, were prospectively enrolled. Patients were confirmed to have had a full series of hepatitis B vaccination. Quantitative serum HBsAb titers were measured and logistic regression analysis with independent variables of age, sex, race, disease phenotype, surgery, medications and a dependent variable of adequate HBsAb titers (> 10 mIU/mL) was performed.

RESULTS

Of the 116 patients enrolled, 57 were boys and 59 were girls. 75 patients had a diagnosis of Crohn disease; 32 had a diagnosis of ulcerative colitis; and 9 patients had been diagnosed as having indeterminate colitis. At the time of the study, 15 patients were taking corticosteroid, 66 on an immunomodulator, and 53 on a biologic. Sixty percent of patients in the 5- to 10-year age group had protective titers versus 22% to 27% in the older groups, P = 0.04. Only 28% of the 116 patients had HBsAb titers of >10m IU/mL. Twenty percent of the patients taking corticosteroids, 27% taking immunomodulators, and 24% taking biologics were found to be seroimmune.

CONCLUSIONS

Nearly two-thirds of pediatric patients with IBD have low titers against hepatitis B virus. Titers were highest in the younger patients. No patient-specific variable, such as the use of immunosuppressants, appeared to influence these low titers.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Antibody Levels and Protection After Hepatitis B Vaccine: Results of a 30-Year Follow-up Study and Response to a Booster Dose

BACKGROUND

The duration of protection in children and adults resulting from hepatitis B vaccination is unknown. In 1981, we immunized a cohort of 1578 Alaska Native adults and children from 15 Alaska communities aged ≥6 months using 3 doses of plasma-derived hepatitis B vaccine.

METHODS

Persons were tested for antibody to hepatitis B surface antigen (anti-HBs) levels 30 years after receiving the primary series. Those with levels <10 mIU/mL received 1 booster dose of recombinant hepatitis B vaccine 2-4 weeks later and were then evaluated on the basis of anti-HBs measurements 30 days after the booster.

RESULTS

Among 243 persons (56%) who responded to the original primary series but received no subsequent doses during the 30-year period, 125 (51%) had an anti-HBs level ≥10 mIU/mL. Among participants with anti-HBs levels <10 mIU/mL who were available for follow-up, 75 of 85 (88%) responded to a booster dose with an anti-HBs level ≥10 mIU/mL at 30 days. Initial anti-HBs level after the primary series was correlated with higher anti-HBs levels at 30 years.

CONCLUSIONS

Based on anti-HBs level ≥10 mIU/mL at 30 years and an 88% booster dose response, we estimate that ≥90% of participants had evidence of protection 30 years later. Booster doses are not needed.

Booster dose vaccination for preventing hepatitis B

BACKGROUND

Antibodies against hepatitis B surface antigen (HBsAg) wane over time following hepatitis B immunisation; hence, it is unclear whether people vaccinated in three-dose or four-dose schedules of the hepatitis B vaccine are still immune when the hepatitis B surface antibody (anti-HBs) level in their body is undetectable, or lower than the level usually considered protective. This question may potentially be answered indirectly by measuring the anamnestic immune response to a booster dose of vaccine. The term 'booster' (or revaccination) refers to an additional dose of hepatitis B vaccine (HBV) given some time post-primary vaccination to induce immune memory and improve protection against hepatitis B virus (HBV) infection.

OBJECTIVES

To assess the benefits and harms of booster dose hepatitis B vaccination, more than five years after the primary vaccination, for preventing HBV infection in healthy individuals previously vaccinated with the hepatitis B vaccine, and with hepatitis B surface antibody (anti-HBs) levels below 10 mIU/mL.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, conference databases, and reference lists of articles to January 2016. We also contacted authors of articles. In addition, we searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials (May 2016).

SELECTION CRITERIA

Randomised clinical trials addressing anamnestic immune response to a booster dose of hepatitis B vaccine, more than five years after the primary vaccination, in apparently healthy participants, vaccinated in a three-dose or four-dose schedule of the hepatitis B vaccine during the primary vaccination, without receiving an additional dose or immunoglobulin.

DATA COLLECTION AND ANALYSIS

Both review authors decided if the identified studies met the inclusion criteria or not. Primary outcomes included the proportion of participants with anamnestic immune response in non-protected participants and signs of HBV infection. Secondary outcomes were the proportion of participants that developed local and systemic adverse events following a booster dose injection. We planned to report the weighted proportion with 95% confidence intervals (CIs).

MAIN RESULTS

There were no eligible randomised clinical trials fulfilling the inclusion criteria of this review.

AUTHORS' CONCLUSIONS

We were unable to include any randomised clinical trials on the topic; only randomised clinical trials will be able to provide an answer as to whether a booster dose vaccination is able to protect against hepatitis B infection.

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.

Immunity to hepatitis B persists in adolescents 15-16 years of age vaccinated in infancy with three doses of hepatitis B vaccine

OBJECTIVE

Vaccination of infants against hepatitis B virus (HBV) using hepatitis B vaccine is effective in preventing the infection during early childhood and there is a growing evidence of long-term protection. So far, no need for a booster dose has been identified in healthy subjects; however further follow-up continues to determine the exact duration of protection. We evaluated antibody persistence and immune response to a hepatitis B vaccine challenge dose in children aged 15-16 years, previously vaccinated with 3-doses of the same vaccine in infancy (third dose received before 18 months of age).

METHODS

A single hepatitis B vaccine challenge dose containing 10μg hepatitis B surface (HBs) antigen was administered to adolescents aged 15-16 years. Blood samples were taken before and one month after the challenge dose to measure anti-HBs antibodies using a chemiluminescence immunoassay. Solicited local and general symptoms, as well as unsolicited and serious adverse events were recorded after the challenge dose.

RESULTS

303 subjects were enrolled, of whom 302 and 293 subjects formed the total vaccinated and according-to-protocol cohorts, respectively. Pre-challenge, 65.4% (95% CI: 59.6-70.9) subjects were seroprotected (anti-HBs antibody concentration ≥10mIU/mL). One month post-challenge, 97.9% (95% CI: 95.6-99.2) were seroprotected, while 90.8% (95% CI: 86.8-93.8) had anti-HBs antibody concentrations ≥100mIU/mL. The post-challenge geometric mean concentration (GMC; 4134.9 [95% CI: 3114.2-5490.1]) was 150-fold higher than the pre-challenge GMC. Overall, 96.9% (95% CI: 94.2-98.6) subjects mounted an anamnestic response. The safety and reactogenicity profile of the hepatitis B vaccine challenge dose was consistent with previous experience.

CONCLUSIONS

Immunity to hepatitis B persists in 15-16 year old adolescents following primary vaccination in infancy.

TRIAL REGISTRATION

http://www.clinicaltrials.govNCT01847430.

Protection Provided by Hepatitis B Vaccine in Adult Population of Chaharmahal and Bakhtiari Province, Iran in 2013

INTRODUCTION

Hepatitis B vaccination has been integrated into National Expanded Program on Immunization in Iran since the year 1993 and young adult national vaccination project was done in 2008. So we have three subpopulations with vaccination coverage for hepatitis B and different antibody levels. Consisting of Subpopulation 1 born after 1993, subpopulation 2 born between 1989 and 1993 and receiving vaccination under adult national project, and subpopulation 3 born prior to the year 1989.

AIM

The present study was conducted to investigate community protection by hepatitis B vaccine in adult population in an accessible population in Iran and compare vaccination coverage, HBs Ab level, and its effective titration among the three above-mentioned subpopulations.

MATERIALS AND METHODS

This cross-sectional study was done on a 3000-individual adult population from all seven counties of Chaharmahal and Bakhtiari province enrolled by clustering. After obtaining written consent and filling out a questionnaire of demographic data and history of hepatitis B vaccination by trained interviewers, necessary blood sample was taken and HBs Ab titration was checked. The data were analysed by chi-square in SPSS 19. The level of significance was considered as 0.05 and effective Ab titration as ≥ 10.

RESULTS

The mean age of the participants was 38.4±16.3 years. Of the participants 48.2% had effective titration. For vaccination coverage, 77.4% were unvaccinated, 20% completely vaccinated, and 2.6% incompletely vaccinated with a significant association with effective titration (p<0.001). Eighty six percent of the subpopulation 1 and 79% of the subpopulation 2 were completely vaccinated, with a significant difference in effective titration between them (p<0.001). Vaccination coverage was higher in men and the single but equal in cities and villages. The effective titration was significantly associated with being married and residence place (p=0.003). There was a significant association between effective titration and the time at vaccination (p<0.001).

CONCLUSION

Protection provided by hepatitis B vaccine in adult population is relatively suitable especially in the youth population; however, catch-up programs of the groups exposed to risk are recommended.

The one year effects of three doses of hepatitis B vaccine as a booster in anti-HBs-negative children 11-15 years after primary immunization; China, 2009-2011

The aim of this study was to evaluate hepatitis B surface antibody (anti-HBs) levels one year after hepatitis B booster vaccination in anti-HBs-negative (<10 mIU/mL) children 11-15 y after primary vaccination. Anti-HBs titers were examined in 235 children who were negative for hepatitis B surface antigen (HBsAg), anti-HBs, and hepatitis B core antibody (anti-HBc). The children were then divided into 3 groups based on their anti-HBs levels pre-booster: Group I, <0 .1 mIU/mL; Group II, 0.1 to <1 .0 mIU/mL; and Group III, 1.0 to <10 .0 mIU/mL. They were vaccinated with 3 doses of hepatitis B vaccine (0-1-6 month, 20 ug), and anti-HBs levels were measured. One month after the first dose, the anti-HBs positive rates (≥ 10 mIU/mL) in Groups I-III were 56.14%, 83.61% and 100%. One month after the third dose, the anti-HBs-positive rates in Groups I-III were 96.49%, 98.36% and 100%. One year after the third dose, the anti-HBs-positive rates in Groups I-III were 73.68%, 75.41% and 98.29%, respectively. Protective levels declined more rapidly for those with lower titers. Children with pre-booster anti-HBs titers of 1-9.9 mIU/mL might not need any booster dose, and the children with pre-booster titers of 0.1-0.9 and <0 .1 mIU/mL might need more than one dose booster vaccination.

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

BACKGROUND AND AIMS

The definition of immune memory after hepatitis B vaccination is still under debate. Therefore, we analysed hepatitis B surface antigen (HBsAg)-specific memory in more detail by investigating the kinetics of humoral and cellular responses after hepatitis B booster vaccination.

METHODS

The anti-HBs kinetics of 23 individuals with anti-HBs titres below 10 IU/l, who had been vaccinated 10-15 years ago, was monitored at day 0, 3, 7, 14 and 28 after booster vaccination. HBsAg-specific IFNγ- and IL5-secreting cells in enriched CD4(+) fraction were measured at day 0, 7 and 28 post-booster by enzyme-linked immunospot assay (ELISpot).

RESULTS

22 of 23 subjects showed similar anti-HBs kinetic curves, including 3 of 4 subjects who did not reach anti-HBs titres of 10 IU/l. The steep anti-HBs increase started between day 3 and 7 and peaked around day 14. A plateau or only minimal changes were visible between day 14 and 28. 17.4% of subjects showed pre-booster cellular responses, and this rate had increased to 47.8% and 56.5% after 7 and 28 days, respectively. The kinetic patterns of T cell responses differed considerably among subjects. A dominance of Th2 responses (IL5 secretion) over Th1 responses (IFNγ secretion) could be observed.

CONCLUSIONS

The presence of B cell memory could be shown by a typical anamnestic anti-HBs response curve after a booster dose in all but one individual. In contrast, T cell responses to booster vaccination, which occurred in approximately 50% of participants, were rather heterogeneous.

Serologic control against hepatitis B virus among dental students of the University of Granada, Spain

Background

To evaluate the immunological situation against hepatitis B virus (HBV) of a cohort of dentistry students, to analyze the behavior of the levels of hepatitis B surface antigen (anti-HBs) after the administration of one or three vaccine doses, and to determine the influence of age and sex on the immune response.

Material and Methods

This retrospective cohort study included students attending the School of Dentistry of the institution where the study was performed from 2005 to 2012 who had completed the public health vaccination calendar for HBV at the age of 12-13. Data on age, sex, basal anti-HBs levels, post-vaccination anti-HBs results and final anti-HBs levels were collected. Comparisons of the basal and final levels, as well as associations regarding age and sex, were performed by means of the Student t and Chi-square tests.

Results

Of the 359 students, 97 (27.02%) had basal antibody concentrations <10 mIU/ml, whereas in 262 the levels of anti-HBs were ≥10 mIU/ml (72.98%). Of the 288 participating students who completed the School´s protocol for immunization, 287 (99.65%) attained a level of protection ≥10 mIU/ml. Globally, there were statistically significant differences between the basal antibody levels and those achieved after administration of the vaccine and booster, but no association with age or sex was observed.

Conclusions

About 70% of dental students vaccinated as preadolescents had serologic evidence of protection against HBV. Administering a booster is associated with the presence of an excellent immune memory. There is clearly a need to reinforce control of the antibody levels in groups at risk, such as Dentistry students.

Key words:Dental students, hepatitis B virus, serologic control.

Immunogenicity of quadrivalent HPV and combined hepatitis A and B vaccine when co-administered or administered one month apart to 9-10 year-old girls according to 0-6 month schedule

BACKGROUND

No immunogenicity data has been reported after a single dose of the quadrivalent HPV vaccine (qHPV-Gardasil®) and no data are available on co-administration of this vaccine with the HAV/HBV vaccine (Twinrix-Junior®). Two pre-licensure studies reported similar anti-HPV but lower anti-HBs titers when co-administering HPV and HBV vaccines.

OBJECTIVES

To assess the immunogenicity of the qHPV and HAV/HBV vaccine when co-administered (Group-Co-adm) or given one month apart (Group-Sep) and to measure the persistence of HPV antibodies three years post-second dose of qHPV vaccine in both study groups.

METHODS

416 9-10 year-old girls were enrolled. Vaccination schedule was 0-6 months. Anti-HAV and anti-HBs were measured in all subjects 6 months post-first dose and 1 month post-second dose. Anti-HPV were measured 6 months post-first dose in Group-Co-adm and in all subjects 1 and 36 months post-second dose.

RESULTS

Six months post-first dose: 100% of subjects had detectable anti-HAV and 56% and 73% had detectable anti-HBs in Group-Co-Adm and Group-Sep, respectively. In Group-Co-adm 94, 100, 99 and 96% had detectable antibodies to HPV 6, 11, 16 and 18, respectively. One month post-second dose of qHPV and HAV/HBV vaccine, in both study groups 99.5-100% of subjects had an anti-HAV titer ≥ 20IU/L, 97.5-97.6% an anti-HBs level ≥ 10IU/L, and 100% had an anti-HPV titer ≥ 3LU. Thirty-six months post-second dose of qHPV all but four subjects (99%) had antibodies to HPV18 and 100% had antibodies to HPV6, 11 and 16. The great majority (97-100%) had an anti-HPV titer ≥ 3 LU. Post-second dose administration of qHPV and HAV/HBV, no meaningful difference was observed in the immune response in the two study groups to any component of vaccines.

CONCLUSIONS

The results indicate that qHPV and HAV/HBV can be given during the same vaccination session. Two doses of of qHPV and HAV/HBV vaccines induce a strong immune response. Three years post-second dose of qHPV, the great majority of subjects had antibodies to HPV types included in the vaccine. A two-dose schedule for pre-adolescents might be a reasonable alternative to the currently approved three-dose schedules.

HIV viraemia during hepatitis B vaccination shortens the duration of protective antibody levels

OBJECTIVES

Individuals with HIV infection often have early waning of protective antibody following hepatitis B virus (HBV) vaccination. HIV viraemia at the time of vaccination may limit the durability of serum anti-HBV surface antibody (HBsAb) levels. We investigated the relationship of HIV plasma viral load (VL) and duration of HBsAb among vaccinees enrolled in the US Military HIV Natural History Study.

METHODS

We included in the study participants who had no history of prior HBV infection, who had received all HBV vaccine doses after HIV diagnosis, and who had demonstrated an initial vaccine response, defined as HBsAb ≥ 10 IU/L. Responders were retrospectively followed with serial HBV serology from the time of the last vaccine dose until the development of waning (HBsAb < 10 IU/L) or the last HBsAb measurement. Time to and risk for waning were evaluated with Kaplan-Meier survival methods and Cox proportional hazards models, respectively.

RESULTS

A total of 186 initial vaccine responders were identified. During 570 person-years of observation, HBsAb waned in 52 of 186 participants (28%). The cumulative proportion maintaining HBsAb ≥ 10 IU/L was 83% at 2 years and 56% at 5 years. Participants with an undetectable VL [hazard ratio (HR) 0.37; 95% confidence interval (CI) 0.18-0.76] or with detectable VL of ≤ 10 000 copies/mL (HR 0.46; 95% CI 0.21-1.00) had reduced risk of waning. Other factors including age, number of vaccine doses, CD4 count, and receipt of highly active antiretroviral therapy (HAART) were not significantly associated with risk of waning HBsAb.

CONCLUSIONS

Undetectable or low HIV VL at the time of HBV vaccination is associated with greater durability of vaccine response in patients with HIV infection.

Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine

Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L) protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

Universal hepatitis B vaccination in Belgium: impact on serological markers 3 and 7 years after implementation

Hepatitis B virus (HBV) can be eliminated by effective universal vaccination. In Belgium, a free-of-charge HBV vaccination programme in infants with catch-up in adolescents was introduced in 1999. To evaluate the effects in <20-year-olds, seroprotection (anti-HBs >11 mIU/ml, according to the assay) and markers of infection (anti-HBc, HBsAg) were assessed in 2443 residual sera collected 7-8 years after implementation of the programme. The maximal prevalence of a solely anti-HBs seroprotective ('vaccinated') serostatus was 82·9% at age 1 year and 60·5% at age 13 years. A clear increase was found in age cohorts targeted by the campaign after a similar serosurvey conducted 4 years earlier. The prevalence of HBV infection remained unchanged at a low level (1·8% in 2006) similar to pre-vaccination data (1993-1994). We conclude that universal HBV vaccination has achieved overall high levels of vaccine-induced immunity, despite regional variations, which may give rise to pockets of susceptible young adults in the future.

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

Hepatitis B (HB) vaccine induces protective levels of antibody response (anti-HBs≥10 mIU/mL) in 90-99% of vaccinees. The levels of anti-HBs antibody decline after vaccination. The aim of this study was to evaluate the persistence of anti-HBs antibodies and immunologic memory in healthy adults at 20 years after primary vaccination with recombinant HB vaccine. Blood samples were collected from 300 adults at 20 years after primary HB vaccination and their sera were tested for anti-HBs antibody by ELISA technique. A single booster dose of HB vaccine was administered to a total of 138 subjects, whose anti-HBs antibody titer was <10 mIU/mL. The sera of subjects were re-tested for the anti-HBs antibody levels at 4 weeks after booster vaccination. At 20 years after primary vaccination 37.0% of participants had protective levels of antibody with geometric mean titer (GMT) of 55.44±77.01 mIU/mL. After booster vaccination, 97.1% of vaccinees developed protective levels of antibody and the GMT rose from 2.35±6.49 mIU/mL to 176.28±161.78 mIU/mL. 125/138 (90.6%) of re-vaccinated subjects also showed an anamnestic response to booster vaccination. At 20 years after primary vaccination with HB vaccine, low proportion of the subjects had protective levels of antibody. However, the majority of the re-vaccinated subjects developed protective levels of anti-HBs and showed an anamnestic response after booster vaccination. Additional follow-up studies are necessary to determine the duration of immunological memory.

Long-term persistence of immunity after vaccination of pre-adolescents with low doses of a recombinant hepatitis B vaccine

BACKGROUND AND AIMS

Recent studies have shown no detectable antibodies and no response to a challenge dose of vaccine 10-20 y after receiving low doses (2.5-5 µg) of recombinant hepatitis B vaccine during first months of life. Little information is available on long-term persistence of immunity after vaccinating pre-adolescents with low doses of hepatitis B vaccine.

RESULTS

The results of 560 subjects were included in this analysis. All subjects had a seroprotective antibody titer (≥10 IU/L) one month post-primary vaccination; 5, 10 and 15 y post-vaccination 95%, 95% and 87% had detectable antibodies, and 82%, 86%, and 68% had a seroprotective antibody titer; GMTs were 73 IU/L, 89 IU/L, and 28 IU/L, respectively. More than 99.4% of subjects had an anamnestic response to a challenge dose of vaccine given 5, 10, or 15 y post-vaccination. Five and ten years post-booster dose 97% and 95% of subjects still have a seroprotective anti-HBs titer with GMTs 16-18-fold higher when compared with those observed 5-10 y post-primary vaccination.

MATERIALS AND METHODS

This randomized trial was initiated in 1996 with the main objective to assess the persistence of antibodies and immune memory 5, 10 and 15 y after vaccinating 8-10 y-old children with three doses of Recombivax 2.5 µg, as well as the short and long-term effect of a booster dose given at different intervals.

CONCLUSIONS

Virtually all children vaccinated at the age of 8-10 y with low doses of hepatitis B vaccine still have an excellent immune memory up to age of 25 y. The results of this study do not support the use of booster doses.