Hepatitis B vaccine response among infants born to hepatitis B surface antigen-positive women

Impact of hepatitis B birth dose on immune response in Pakistani children: an open-label, non-inferiority randomized controlled trial, implications for achieving SDG target

BACKGROUND

Despite presence of hyperendemic areas, the national immunisation schedule in Pakistan does not include a hepatitis B birth dose, placing newborns at an additional risk of acquiring hepatitis B. This study aimed to assess the impact of adding hepatitis B birth dose in existing national vaccination schedule.

METHODS

An open label, randomised controlled non-inferiority trial enrolled 296 healthy near-term mothers to intervention and control groups. Newborns in the intervention group received a hepatitis B birth dose along with routine immunisation vaccines, while control group newborns received vaccinations under the national schedule. Seroprotection was measured and compared at birth and 8 weeks after administering the third dose of pentavalent vaccine. The risk ratio of seroprotection was computed and compared with the delta value set at 5%.

RESULTS

The study found that 95.8% of infants in the intervention group achieved seroprotection, which was significantly higher than the control group's 58.7%. The difference in risk ratio of seroprotection was 1.62 (CI95: 1.37-1.93), with the upper limit of the CI below the delta margin, confirming non-inferiority. The time interval between birth and the first hepatitis B immunisation shot was a predictor of seroprotection, with an odds ratio of 1.79 (CI95: 1.01-2.9).

CONCLUSION

Our study indicates that adding a hepatitis B birth dose to the immunisation schedule in Pakistan is non-inferior to the existing one. This can also contribute towards Pakistan's achievement of the SDG target of reducing hepatitis B surface antigen seroprevalence in children under 5 years of age.

TRIAL REGISTRATION NUMBER

NCT04870021.

An Evidence-based Practical Guide to Vaccination for Hepatitis B Virus

The hepatitis B virus (HBV) is highly infectious, with over 292 million chronically infected people worldwide and up to 2.4 million in the United States. Following infection, clinically silent liver damage can ensue, but symptoms or signs of advanced disease, including cirrhosis and hepatocellular carcinoma, can take decades to emerge. HBV has the heaviest public health burden of all hepatitis viruses and has now surpassed other major communicable diseases (eg, HIV, diarrheal disease, malaria, tuberculosis) as a leading cause of death globally. Preventing transmission is essential, and efforts are in place to reinforce screening, vaccination, and routine follow-up. Three safe and effective vaccines are available in the United States and other countries for HBV prevention, and the benefits of vaccination in preventing infection and its sequelae have been substantiated. For the first time in over 25 years, a new Food and Drug Administration-approved vaccine is available that offers a high degree of immunogenicity after 2, rather than 3, injections. Persistent challenges include the underutilization of vaccination, choice of vaccine, incomplete vaccinations, varying needs in different populations, management of nonresponders or those with undocumented or incompletely documented vaccination courses, and questions about whether and when booster injections may be needed. A panel of US academic hepatologists with expertise and experience in preventing and managing HBV infection have collaborated to write this practical clinical paper intended to guide clinicians in vaccinating for HBV and address questions that regularly arise in the clinic.

Outcomes of Hepatitis B Immunoglobulin and Hepatitis B Vaccination in High-Risk Newborns Born to HBeAg-positive Mothers

BACKGROUND

To evaluate the protective efficacy of a hepatitis B (HB) vaccination program in Taiwan among high-risk children.

MATERIAL AND METHODS

Children born to HBeAg-positive mothers from 2001 to 2010 were invited back. Blood samples for hepatitis B virus (HBV) seromarkers were taken and the children underwent hepatobiliary ultrasonography. Perinatal factors including delivery mode and vaccination history were collected from their medical records. According to the results of HBV serological markers, the children were initially classified into five groups: HBV naïve, HB vaccine responder, HBsAg carrier, recovered from HBV infection, and anti-HBc-positive alone. Children in the HBV naïve and anti-HBc-positive alone groups who presented with an anamnestic response after a booster HB vaccine were re-assigned to the vaccine responder and recovered from infection groups, respectively.

RESULTS

All of the 196 enrolled children received postnatal hepatitis B immunoglobulin (HBIG) and HB vaccinations, of whom one was HBV naïve (0.5%), 109 were vaccine responders (55.6%), 21 were carriers (10.7%), and 65 recovered from infection (33.2%). Among the 21 carriers, 14 (66.7%) presented in the immunotolerant phase. Cesarean section was the only significant perinatal factor between the carriers (5.3%) and those who recovered from infection (37.7%) (p=0.007).

CONCLUSIONS

In this study, there was a 43.9% HBV infection rate and 10.7% HBsAg carrier rate in high-risk Taiwanese children even after receiving HBIG and HB vaccinations. Cesarean section may protect newborns from becoming HBsAg carriers, while HBV genotype and time of HBIG injection did not contribute to the HBV carrier rate.

The optimal interval for post-vaccination serological test in infants born to mothers with positive hepatitis B surface antigen

Postvaccination serologic testing (PVST) is utilized to monitor the success or failure of vaccination against hepatitis B virus (HBV) infection in infants of hepatitis B surface antigen (HBsAg) positive mothers. This secondary analysis of 1255 infants of HBsAg-positive mothers at 7-14 months age included in two prospective studies aimed to determine the optimal interval for PVST after three hepatitis B vaccine doses. HBsAg and anti-HBs were quantitatively tested with microparticle enzyme immunoassay. The average PVST interval was 3.8 ± 2.2 months. Overall, 1.7% (21/1255) infants had anti-HBs <10 mIU/mL. The non-response rates were 1.6%, 1.1%, 0.9%, 0.7%, 1.1%, 0.7%, and 5.7% when PVST was performed at an interval of 1, 2, 3, 4, 5, 6, and 7-8 months after the third vaccine dose, respectively. Compared with 1 month of PVST interval, the non-response rate in infants who underwent PVST 7-8 months was significantly higher (χ² = 4.616, P = .032). Anti-HBs titers were significantly declined in infants with medium responses when PVST was performed with longer intervals (χ² = 27.592, P < .001), actually declined from interval of 6, and 7-8 months (Z = -3.177, P = .001 and Z = -3.715, P < .001), respectively. These results indicate that PVST may be performed at the age of 7-12 months for infants vaccinated on 0, 1, and 6-month schedule. To identify non-responders as early as possible, we suggest that PVST is performed at 7 months age or 1 month after the final vaccine dose.

National Perinatal Hepatitis B Prevention Program: 2009-2017

OBJECTIVES

To assess trends and programmatic outcomes among infants born to hepatitis B surface antigen (HBsAg)-positive women from 2009 to 2017 and case-managed by the Centers for Disease Control and Prevention's national Perinatal Hepatitis B Prevention Program (PHBPP).

METHODS

We analyzed 2009-2017 annual programmatic reports submitted by 56 US jurisdictions funded through the Centers for Disease Control and Prevention's PHBPP to assess characteristics of maternal-infant pairs and achievement of objectives of infant hepatitis B postexposure prophylaxis, vaccine series completion, and postvaccination serologic testing (PVST). We compared the number of maternal-infant pairs identified by the program with the number estimated born to HBsAg-positive women from 2009 to 2014 and 2015 to 2017 by using a race and/or ethnicity and maternal country of birth methodology, respectively.

RESULTS

The PHBPP identified 103 825 infants born to HBsAg-positive women from 2009 to 2017, with a range of 10 956 to 12 103 infants annually. Births estimated annually to HBsAg-positive women increased nonsignificantly from 24 804 in 2009 to 26 444 in 2014 (P = .0540) and 20 678 in 2015 to 20 832 in 2017 (P = .8509). The proportion of infants identified annually increased overall from 48.1% to 52.6% (P = .0983). The proportion of case-managed infants receiving postexposure prophylaxis, at least 3 vaccine doses, and PVST increased overall from 94.7% to 97.0% (P = .0952), 83.1% to 84.7% (P = .5377) and 58.8% to 66.8% (P = .0002), respectively.

CONCLUSIONS

The PHBPP has achieved success in managing infants born to HBsAg-positive women and ensuring their immunity to hepatitis B. Nonetheless, strategies are needed to close gaps between the number of infants estimated and identified, increase vaccine series completion, and increase ordering of recommended PVST for all case-managed infants.

Immunogenicity of Hepatitis B Vaccine in Preterm or Low Birth Weight Infants: A Meta-Analysis

CONTEXT

The study aims to quantitatively assess the immune response to hepatitis B vaccine in infants born preterm or with low birth weight.

EVIDENCE ACQUISITION

In December 2018, a literature search was conducted in 4 databases without date restrictions. The pooled ORs, mean differences, and their corresponding 95% CIs were calculated with random-effects models using the DerSimonian-Laird estimator. The potential risk of bias of each study was assessed using the Newcastle-Ottawa Scale. The stability and publication bias of the pooled estimates were also evaluated. Analyses were completed in 2019.

EVIDENCE SYNTHESIS

A total of 27 studies including 22,202 infants were eligible for analysis. The studies found that infants born preterm had significantly poorer immune responses to the hepatitis B vaccine. Preterm infants were 1.36 times more likely to exhibit nonresponse to the hepatitis B vaccine (95% CI=1.12, 1.65, p=0.002) compared with their full-term counterparts. The pooled estimates for preterm birth may be subject to a potential publication bias. However, these results were stable, as suggested by the leave-one-out analysis and fail-safe number. The association between low birth weight and impaired immune response to the hepatitis B vaccine was not statistically significant when birth weight was dichotomized at 2,500 g.

CONCLUSIONS

These findings suggest an association between preterm birth and lowered immune responses to hepatitis B vaccine.

Hepatitis B Virus Immunization and Neonatal Acquisition of Persistent Infection in England and Wales

Background

It is believed that between 2% and 5% of infants born to hepatitis B virus (HBV)-infected mothers at a high risk of perinatal transmission will become persistently infected despite immunization starting at birth. We investigated factors associated with breakthrough infections.

Methods

Sixty-nine samples from HBV-infected infants born between 2003 and 2015 were tested for HBV serological and molecular markers. Sequencing and epitope phenotyping were used to investigate alterations in hepatitis B surface antigen (HBsAg) sequence and antigenicity in infants and in mothers known to have transmitted and not to have transmitted virus to their infants.

Results

Vaccine/hepatitis B immune globulin uptake was complete in the majority of HBV-infected infants. A minority (8 [12%]) had detectable plasma antibody to HBsAg at 12 months. Twenty-five of 68 (37%) infants harbored a virus with amino acid changes in the HBsAg "a" determinant, of which 13 displayed altered HBsAg antigenicity. Viral load was 30-fold higher in maternal samples from those who transmitted.

Conclusions

Our data provide evidence to suggest that immune selection drives change at mother-infant transmission, resulting in the alteration of HBsAg antigenicity. These changes may play a role in immunization failure, but other factors including viral load may be more important. Continued monitoring of vaccine efficacy is essential.

Challenge of hepatitis C in Egypt and hepatitis B in Mauritania

Egypt has one of the highest prevalence rates of hepatitis C virus (HCV) in the world, mostly with genotype 4 that is highly associated with severe fibrosis. As a consequence, hepatocellular carcinoma has become the leading cause of cancer in this country. Mauritania is a highly endemic area for hepatitis B virus (HBV). HBV and HCV could both be iatrogenically transmitted through infected blood products, infected needles, and medical equipment improperly sterilized. Adequate and efficient healthcare and public health measures with good surveillance programs, access for screening, prevention strategies, and successful treatment are needed to halt the spread of these diseases. Herein, we have reviewed the epidemiology, modes of transmission, predisposing factors, and novel treatment modalities of these viruses. We have proposed practices and interventions to decrease the risk of transmission of HCV and HBV in the affected countries, including strict adherence to standard precautions in the healthcare setting, rigorous education and training of patients and healthcare providers, universal screening of blood donors, use of safety-engineered devices, proper sterilization of medical equipment, hepatitis B vaccination, as well as effective direct-acting antiviral agents for the treatment of HCV.

Persistence of Vaccine-Induced Immunity in Preschool Children: Effect of Gestational Age

Background

A program of immunization that ensures optimal development of acquired immunity should be carried out in all healthy newborns. The aim of the present study was to verify, at 2.5–3 years after the last dose of basic vaccination, if preschool children who have been delivered preterm and at term differ in their levels of post-vaccination protective antibodies.

Material/Methods

Humoral response was assessed in 352 children (mean age: 5.22±0.34 years) who received a series of obligatory vaccinations in the period from birth to 2.5–3 years of age. Antibodies (in IgG class) against vaccine antigens – diphtheria (D), tetanus (T), pertussis (P), Haemophilus influenzae type b (Hib), poliomyelitis (IPV), measles, mumps, and rubella (MMR) – were measured using ELISA. The level of antibodies against hepatitis B (HBV) was assessed by chemiluminescence.

Results

All children had been immunized according to the Polish National Vaccination Program. The group of 352 children eligible for the study included 46 (13.1%) preschoolers delivered preterm (32–36 weeks of gestation), and 306 (86.9%) born at term (37–42 weeks of gestation). All children maintained seroprotective antibody levels against polioviruses type 1, 2, and 3 (>12 mIU/mL), and against measles antigens (>300 U/mL). No statistically significant differences were found in the proportions of preschoolers born preterm and at term who were seroprotected against other vaccine antigens.

Conclusions

Among preschool children who were immunized according to chronological age, those we were born late preterm do not seem to differ in vaccine-induced immunity from those who were born full-term.

Mother-to-child transmission of hepatitis B: Examining viral cut-offs, maternal HBsAg serology and infant testing

BACKGROUND & AIMS

Antipartum antiviral therapy in the setting of high viral load is recommended to prevent mother-to-child transmission of hepatitis B although recommended viral load cut-offs vary. Quantitative HBsAg has been proposed as an alternative screening strategy to identify high viral load in this setting. Guidelines suggest testing all infants for vaccine response and infection. We set out to re-examine viral load cut-offs; the predictive value of quantitative HBsAg and the need for follow-up infant testing in our cohort.

METHODS

A retrospective cohort study of 469 HBsAg positive mother-baby pairs from 2 tertiary hospitals in Sydney was performed. Antiviral therapy (lamivudine or tenofovir disoproxil fumarate) was offered to women with viral load ≥6 log₁₀  IU/mL (high) from 32 weeks gestation. Transmission and vaccine response was analysed according to viral load. The utility of quantitative HBsAg in identifying high viral load was examined.

RESULTS

Mother-to-child transmission only occurred in setting of high viral load, in 0.85% (1/117) of those who received antiviral therapy and in 8.66% (2/23) of those who chose not to. Quantitative HBsAg did not accurately identify high-risk mothers HBV DNA ≥6 log₁₀  IU/mL. Successful infant vaccine response was 98.7% overall, and 99.4% when viral load was <6 log₁₀  IU/mL.

CONCLUSION

Antiviral therapy initiated at 32 weeks when maternal viral load is ≥6 log₁₀  IU/mL almost completely abrogates transmission. Quantitative HBsAg does not reliably predict high viral load. When maternal viral load is <6 log₁₀  IU/mL, high vaccine efficacy and zero transmission suggests testing infants is of little value.

Three decades of neonatal vaccination has greatly reduced antenatal prevalence of hepatitis B virus infection among gravidae covered by the program

OBJECTIVES

To evaluate the impact of three decades of hepatitis B vaccination in infancy on antenatal prevalence of hepatitis B surface antigen (HBsAg) carriage in 93,134 Hong-Kong born gravidae managed in 1997-2015.

METHODS

Annual prevalence of HBsAg carriage on routine antenatal screening was examined with respect to maternal year of birth in three periods i.e. pre-1983 (before availability of vaccination), 1983-1988 (vaccination of infants born to HBsAg-carriers), and after 1988 (universal vaccination).

RESULTS

Overall HBsAg carriage was 8.3% (7737/93,134), decreasing from 10.5% in 1997 to 6.5% in 2015 (p < 0.001), and from 8.8%, 7.0% to 3.1%, respectively, for the three period-of-birth cohorts (p < 0.001). Annual prevalence decreased from 9.9% in 1997 to 7.5% in 2015 (p < 0.001) in the pre-1983 cohort, but showed neither difference nor trend in the other two cohorts. However, the annual prevalence showed significantly falling trends from the pre-1983 to the post-1988 cohorts for the years 2007-2008 and 2010-2015.

CONCLUSIONS

A progressive decline in overall annual prevalence of antenatal HBsAg carriage was found, with a consistently significant decline among the three cohorts for the years 2007-2008 and 2010-2015, providing evidence that universal hepatitis B vaccination in infancy has reduced significantly antenatal prevalence of HBsAg carriage in Hong Kong.

Cost Analysis of Single-Dose Hepatitis B Revaccination Among Infants Born to Hepatitis B Surface Antigen-Positive Mothers and Not Responding to the Initial Vaccine Series

OBJECTIVES

Infants born to mothers who are hepatitis B surface antigen (HBsAg) positive are at risk for perinatal hepatitis B infection. As prevention, these infants receive a series of 3 or 4 doses of hepatitis B vaccine starting at birth and postvaccination serologic testing. Infants with antibody levels <10 mIU/mL are considered vaccine nonresponders and should be revaccinated. The objective of this cost analysis was to assess a single-dose revaccination strategy among infant nonresponders.

METHODS

We used a decision analytic tree to compare the costs of a single-dose revaccination strategy with the costs of a 3-dose revaccination strategy. The analysis consisted of 3 epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination. We assumed health outcomes in each strategy were the same, and we evaluated costs from the societal perspective using 2016 US dollars. We conducted sensitivity analyses on key variables, including the minimum required efficacy of a single revaccination dose.

RESULTS

In all analyses, the single-dose revaccination strategy was a lower-cost option than the 3-dose revaccination strategy. Under the assumption that all revaccination visits were previously unscheduled, single-dose revaccination reduced the cost per infant by $119.81 to $155.72 (depending on the scenario). Across all scenarios, the most conservative estimate for the threshold efficacy (the minimum efficacy required to result in a lower-cost option) value of single-dose revaccination was 67%.

CONCLUSIONS

For infants who were born to HBsAg-positive mothers and who were not responding to the initial vaccine series, a single-dose revaccination strategy, compared with a 3-dose revaccination strategy, reduced costs across several scenarios. These results helped inform the Advisory Committee on Immunization Practices' vote in February 2017 to recommend single-dose revaccination.

Effect of HBIG combined with hepatitis B vaccine on blocking HBV transmission between mother and infant and its effect on immune cells

The effect of hepatitis B immune globulin (HBIG) combined with hepatitis B vaccine on blocking hepatitis B virus (HBV) transmission between mother and infant and its effect on immune cells were studied. Ninety newborn infants confirmed to be HBV surface antigen (HBsAg)-positive were divided equally into three groups. Group A newborns received the hepatitis B vaccine at 0, 1 and 6 months after birth (10 µg/time). Group B newborns received an intramuscular injection of 100 IU HBIG 2 h after birth before the same treatment as group A. Mothers of group C newborns received three gluteus maxinus injections of 200 IU HBIG. The newborns in group C got the same treatment as group B. The blocking effect of HBV transmission between mother and infant was evaluated, and cell immune function was assessed. There were significant differences in comparison of blocking success rates between group A and B, and between group A and C as well (p<0.05). At the end of 12 months follow-up, the CD4⁺ level and CD4⁺/CD8⁺ ratio in group C were higher thanthose in group A and B (p<0.05). In addition, the level of CD8⁺ T lymphocyte in group C was lower than those in group A and B (p<0.05). In comparison of levels of CD4⁺T lymphocyte at the end of 12 months follow-up and 24 h after birth, the differences were significant (p<0.05) in bothgroup B and C. The differences of IFN-γ levels betweengroups B/C and group A were significant (p<0.05). Forthose newborn infants born to mothers who were positivefor both HBsAg and HBeAg, HBIG intervention formothers during late pregnancy, together with combinedtreatment of HBIG and hepatitis B vaccine for infants, gavebetter blocking result of HBV transmission.

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.

Recommendations for the treatment of hepatitis B in 2017

The therapeutic goal which is currently unfrequent but realistic in HBV infected patients is sustained HBsAg clearance. It is preceded by the loss or significant suppression of HBV replication and leads to inhibition of the progression of liver fibrosis, normalization of biochemical indicators of liver damage, reduction in the risk of hepatocellular carcinoma, prolongation of survival, prevention of HBV infection in the transplanted organ in post-transplant patients, enhancement of the quality of life, inhibition or reversal of extrahepatic changes associated with HBV infection, and halting of the spread of HBV infections. Recommendations of Polish Group of Experts for HBV for 2017 provide guidelines to assess treatment eligibility, choice of the first-line drug, monitoring and duration of treatment, management of treatment failure as well as therapy of HBV associated cirrhosis or hepatocellular carcinoma. Moreover it contains advice for treatment of HBV infection in children, females planning pregnancy or pregnant. We also included recommendations for pre- and post-exposure prophylaxis, prevention of HBV transmission from mother to infant, after liver transplantation, on immunosuppressive therapy and during HCV treatment.

Long-term persistence of immunity after hepatitis B vaccination: Is this substantiated by the literature?

Hepatitis B vaccination is held to provide life-long protection against hepatitis B virus (HBV) infection, but evidence for this notion remains wanting, since no studies have assessed the vaccinees in their fourth decade of life. Indeed, there are several reports indicating that despite vaccination in infancy, the prevalence of HBV infection still increased with age in the vaccinees, and that both anti-HBs titer and anamnestic response declined with age. Clearly it is time to clarify the long-term protection conferred by vaccination in infancy, and to implement remedial measures such as booster doses of vaccine in subjects without immunoprotection.

Minimization of hepatitis B infection among children in Jiangsu, China, 12years after integration of hepatitis B vaccine into the expanded program on immunization

BACKGROUND

China has integrated hepatitis B vaccine into the Expanded Program on Immunization since 2002. We aimed to survey the seroprevalence of and immunity to hepatitis B virus (HBV) in children born from 2002 to 2014 in Jiangsu, China.

METHODS

Totally 3442 children (M:F=2072:1370) at the age of 7months to 12years (5.5±3.6), from five cities and rural areas across Jiangsu province, were enrolled. Blood samples were measured for HBV markers by ELISA and quantitative microparticle enzyme immunoassay. HBV DNA was tested by real-time PCR and S region was amplified by nested PCR.

RESULTS

Twelve (0.35%) children were positive for hepatitis B surface antigen (HBsAg) and 34 (0.99%) were HBsAg negative and positive for antibody against hepatitis B core antigen (anti-HBc). Totally 2542 (73.85%) children had anti-HBs levels ⩾10mIU/ml and 535 (15.54%) with 2-9.9mIU/ml. All 12 HBsAg-positive children had detectable HBV DNA with a mean level of 6.1±1.7logIU/ml (3.3-8.1logIU/ml); 8 were genotype C and 4 were genotype B. No mutation was detected in the a determinant of HBsAg. HBV DNA was not detected in all the 34 children with positive anti-HBc and negative HBsAg.

CONCLUSION

HBsAg prevalence among children in Jiangsu born after the introduction of universal vaccination against hepatitis B has significantly decreased. No mutation of S gene is associated with vaccine failure in the cohort of children.

Changes in the anti-HBc profile of infants born to HBV infected mothers from Iran

From 2007 to 2014, 328 infants born to hepatitis B surface antigen (HBsAg) positive mothers, who received passive-active immunization against hepatitis B at birth were tested for HBsAg, antibody to hepatitis B core antigen (anti-HBc) and antibody to hepatitis B surface antigen (anti-HBs) at 12-15months of age. Thirteen (4%) cases were HBsAg positive. Forty-four infants who were anti-HBs, anti-HBc positive (group 1) and twenty-one infants who were anti-HBc positive alone (group 2) were identified. Both groups were followed-up annually for testing anti-HBs and anti-HBc to verify if anti-HBc was of maternal origin. In group 1, anti-HBc disappeared in 41 cases at month 24, and it disappeared from the remaining 3 cases at month 36. In group 2, anti-HBc disappeared in 18 cases at month 24 and in the remaining 3 cases at month 36. The results show that maternal anti-HBc may persist up to 3years in some children.

Prophylaxis of vertical HBV infection

INTRODUCTION

An appropriate management of HBV infection is the best strategy to finally reduce the total burden of HBV infection. Mother-to-child transmission (MTCT) is responsible for more than one third of chronic HBV infections worldwide. Because HBV infection in infancy or early childhood often leads to chronic infection, appropriate prophylaxis and management of HBV in pregnancy is crucial to prevent MTCT.

AREAS COVERED

The prevention of HBV vertical transmission is a complex task and includes: universal HBV screening of pregnant women, administration of antivirals in the third trimester of pregnancy in women with high viral load and passive-active HBV immunoprophylaxis with hepatitis B vaccine and hepatitis B immune globulin in newborns of all HBV infected women.

EXPERT OPINION

Universal screening of pregnant women for HBV infection, early identification of HBV DNA level in HBV-infected mothers, maternal treatment with class B according to FDA antivirals and passive/active anti-HBV immunoprophylaxis to newborns of HBV-positive mothers are crucial strategies for reducing vertical HBV transmission rates. Consideration of caesarean section in order to reduce the risk of vertical HBV transmission should be recommend in HBV infected pregnant women with high viral load despite antiviral therapy or when the therapy in the third trimester of pregnancy is not available.

Immune persistence after hepatitis B vaccination in infancy - Fact or fancy?

The hepatitis B vaccine has been introduced for more than 3 decades. In Hong Kong, excellent vaccine coverage through an efficient public health care system, together with supplemental programmes and easy availability of the vaccine, meant that most young pregnant women, and university students at entrance, should have been protected. Yet significant correlations in the prevalence of HBV infection with age were found in these groups of subjects, increasing from low to high endemicity rates from late teenage to the early twenties. This can only be attributed to vaccine failure, and there is cumulating evidence that several factors are involved, including the failure to respond to a primary series of hepatitis B vaccination in infancy, the waning of antibody titer with age, and loss of anamnestic response in a significant portion of the vaccinees. The duration of protection conferred by hepatitis B vaccination in infancy should be re-examined and remedial measures undertaken if its long term protection is found to be insufficient. Otherwise, the efforts to control HBV infection, especially in high endemicity regions, with universal vaccination in infancy would be rendered futile.

Update: Shortened Interval for Postvaccination Serologic Testing of Infants Born to Hepatitis B-Infected Mothers

Infants born to hepatitis B-infected mothers receive postexposure prophylaxis to reduce their risk for perinatal hepatitis B virus (HBV) infection. Postexposure prophylaxis consists of hepatitis B (HepB) vaccine and hepatitis B immune globulin administered within 12 hours of birth, followed by completion of the 3-dose or 4-dose HepB vaccine series. Postvaccination serologic testing (PVST) assesses an infant's response to HepB vaccination and has typically occurred at age 9-18 months. This report provides a CDC update recommending shortening the interval for PVST from age 9-18 months to age 9-12 months. Providers should order PVST (consisting of hepatitis B surface antigen [HBsAg] and antibody to HBsAg [anti-HBs]) for infants born to HBsAg-positive mothers at age 9-12 months (or 1-2 months after the final dose of the vaccine series, if the series is delayed). This recommendation was prompted by the discontinuation of production of Hib/HepB vaccine (Comvax) and new data from the Enhanced Perinatal Hepatitis B Prevention Program supporting PVST 1・2 months after receipt of the last HepB vaccine dose, and at age ≥9 months.

Hepatitis B vaccine adverse events in China: risk control and regulation

The death of 17 children raised public fears over infant hepatitis B vaccination in China. Though the relation between hepatitis B and children's death was denied after prudent investigation, the negative impact remained. In order to prevent or minimize adverse events after vaccination, special strategy including regulation and reimbursement should be developed.

Immune response in infants after universal high-dose hepatitis B vaccination: A community-based study in Beijing, China

BACKGROUND

Vaccination of infants beginning at birth is recommended to prevent Hepatitis B virus (HBV) infection in China. Compared to 5 μg/dose vaccine administered in other regions in China, a three-dose HB recombinant yeast vaccine at 10 μg/dose has been administered for infants within 24h after birth, 1 month and 6 months of age in Beijing since 2006. In a community-based retrospective cohort study, factors influencing immunologic vaccine response were evaluated.

METHODS

A total of 3670 infants who completed a 3-dose 10 μg recombinant HB vaccine regimen and born to hepatitis B antigen negative mothers were included. The effect on anti-HBs titers of maternal nutrient status, infants' birth condition, growth factors, timeliness of vaccination, dosing interval and the interval until post-vaccination serologic testing (PVST) were evaluated.

RESULTS

A total of 3666 infants with no markers of HBV infection were included in analysis. The mean anti-HB titers were 1767.17 mIU/ml. Only 16.9% of the infants completed their PVST within 30-59 days after the final dose of vaccination. Multivariate linear regression analysis showed that delay in PVST (β=-0.097, p<0.0001) and maternal folic acid supplementation (β=0.067, p=0.002) were associated with log-transformed anti-HB titers. Also a trend toward significant association was observed between the calcium supplementation of infants and log-transformed anti-HBs titers (β=0.062, p=0.057). Longer interval between dose 2 and dose 3 was not observed to increase the anti-HB titers after cofactors adjustment.

CONCLUSIONS

Our findings illustrate the importance of timing of PVST to avoid unnecessary revaccination. Multi-center large cohort studies should verify the effect and magnitude of folate and calcium supplementation on HB vaccine response.

Effects of hepatitis B immunization on prevention of mother-to-infant transmission of hepatitis B virus and on the immune response of infants towards hepatitis B vaccine

BACKGROUND

Combined immunization with hepatitis B immunoglobulin (HBIG) plus hepatitis B vaccine (HB vaccine) can effectively prevent perinatal transmission of hepatitis B virus (HBV). With the universal administration of HB vaccine, anti-HBs conferred by HB vaccine can be found increasingly in pregnant women, and maternal anti-HBs can be passed through the placenta. This study was designed to evaluate the effect of hepatitis B immunization on preventing mother-to-infant transmission of HBV and on the immune response of infants towards HB vaccine.

METHOD

From 2008 to 2013, a prospective study was conducted in 15 centers in China. HBsAg-positive pregnant women and their infants aged 8-12 months who completed immunoprophylaxis were enrolled in the study and tested for HBV markers (HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc). Antepartum administration of HBIG to HBsAg-positive women was based on individual preference. HBsAg-negative pregnant women and their infants of 7-24 months old who received HB vaccines series were enrolled and tests of their HBV markers were performed.

RESULTS

1202 HBsAg-positive mothers and their infants aged 8-12 months were studied and 40 infants were found to be HBsAg positive with the immunoprophylaxis failure rate of 3.3%. Infants with immunoprophylaxis failure were all born to HBeAg-positive mothers of HBV-DNA ≥6 log₁₀copies/ml. Among infants of HBeAg-positive mothers, immunoprophylaxis failure rate in vaccine plus HBIG group, 7.9% (29/367), was significantly lower than the vaccine-only group, 16.9% (11/65), p=0.021; there was no significant difference in the immunoprophylaxis failure rate whether or not antepartum HBIG was given to the pregnant woman, 10.3% (10/97) vs 9.0% (30/335), p=0.685. Anti-HBs positive rate was 56.3% (3883/6899) among HBsAg-negative pregnant women and anti-HBs positive rate was 94.2% in cord blood of anti-HBs-positive mothers. After completing the HB vaccine series, anti-HBs positive rate among infants with maternal anti-HBs titers of <10 IU/L, 10-500 IU/L and ≥500 IU/L was 90.3% (168/186), 90.5% (219/242) and 80.2% (89/111) respectively, p=0.011. Median titers of anti-HBs (IU/L) among infants in the three groups was 344.2, 231.9 and 161.1 respectively, p=0.020.

CONCLUSIONS

HBIG plus HB vaccine can effectively prevent mother-to-infant transmission of HBV, but no HBV breakthrough infection was observed in infants born to HBeAg-negative mothers who received HB vaccine with or without HBIG after birth. Antepartum injection of HBIG has no effect on preventing HBV mother-to-infant transmission. High maternal titer of anti-HBs can transplacentally impair immune response of infants towards HB vaccine.