Hepatitis B vaccination strategies tailored to different endemicity levels: some considerations

Hepatitis B immunization status and risk factors of people aged 1 to 69 in Huangpu District, Shanghai, China

Background

China has long been with high Hepatitis B Virus(HBV) prevalence in the world. The HBV prevalence of people aged 1-59 decreased to less than 8% in 2006, and by 2020, HBsAg positive rate of children aged <5 decreased to less than <1% which was due to the free three-dose hepatitis B(HepB) immunization for newborns nationwide since 2002. Huangpu district was selected as one of the pilot areas for free Hep B vaccination in newborns since 1986, which formed an early protection in the population from mother-to-child transmission. However, the existed HBV infected people were still needed to be discovered, evaluated whether to receive antiviral therapies and intervened with health education in order to reduce the incidence of viral hepatitis related hepatocellular carcinoma (HCC) and also reach the goal to eliminate public health hazards of viral hepatitis by 2030.

Objective

To know HepB immunization status among people aged 1 to 69 in Huangpu district of Shanghai, and find out risk factors changes of HBV infection.

Methods

Cross-sectional study was applied to analyze the HepB immunization status and related risk factors by carrying out survey among 706 participants aged 1 to 69 years old. Blood samples were collected for detection of serological HBV markers including hepatitis B surface antigen(HBsAg), hepatitis B surface antibody(HBsAb) and hepatitis B core antibody(HBcAb). Participants with HBsAg positive were required to complete additional examinations such as alanine aminotransferase(ALT), aspartate aminotransferase(AST), total bilirubin, albumin, globulin, liver fibroscan and liver ultrasound.

Results

For participants aged 1 to 14, the positive rate of HBsAg, HBsAb and HBcAb was 0.00, 50.00 and 30.46%, respectively. The HBsAb positive rate reached a peak of 90.91% at 2 years old, and then showed a significant downward trend (χ2 = 55.612, p < 0.001). All the participants have completed three-dose Hep B vaccination, however for the second dose, those who vaccinated 30 days later than the appointed time(aged one month) got higher HBcAb prevalence than those who vaccinated on time(χ2 = 5.87, p = 0.015). Two mothers were found HBsAg positive, but there was no significant difference in children's HBcAb positive rates regardless of the mothers' HBsAg results. For participants aged 15 to 69, the positive rate of HBsAg, HBsAb and HBcAb was 4.21, 44.25 and 49.23%, respectively. Multivariate analysis for HBcAb positive among people aged 15 to 69 showed that age(50-69) and HBsAb positive were the risk factors for HBcAb positive(p < 0.05). Higher education was the protective factor for HBcAb positive(p < 0.05). After the screening for HBsAg, 22 participants were tested HBsAg positive and required additional examinations, and a total of 12 completed all the examinations. One participant was recognized as active HBV infection without antivirus treatment. Among the 12 participants, 2 have received antiviral treatment before and 4 had a history of HBV infection in family members.

Conclusion

In this study, HBsAg positive rate of those who aged 1 to 14 was 0.00%, which indicated that the HepB immunization has achieved a lot in protecting children from being infected. However, failing to get timely Hep B vaccination could be an influencing factor for HBcAb positive in children. As a result, additional tests for HBV DNA could be done to specify an HBV infection and more attention should be paid to the timeliness of Hep B vaccination in the next step. The HBcAb positive rate of people aged 1 to 69 was relatively higher than that of other provinces. Despite of the limited participants with full examinations, we should still put emphasis on HBV treatment and the possibility of transmission within families.

Characterizing mothers and children at risk of being under-immunized in India: A latent class analysis approach

OBJECTIVES

While India has made substantial progress in introducing new vaccines and scaling up immunization coverage, inequities persist sub-nationally. This study was performed to investigate the risk of under-immunization based on class membership and to identify heterogeneous classes based on sociodemographic characteristics in pediatric and maternal populations in India through latent class analysis.

METHODS

Data from the most recent National Family Health Survey conducted in 2015-2016 were used. Latent class analysis was used to model immunization coverage in children aged 12-23 months and mothers, and to identify subgroups to characterize those at risk of not being immunized.

RESULTS

Patterns of sociodemographic characteristics were found to contribute to non-immunization or under-immunization among pediatric and maternal populations in India. Individuals who fit into one of three categories were identified in both populations: those at high, medium, and lower risk of not being immunized. Lower socioeconomic status, lack of antenatal care, and lower maternal education put individuals at higher risk of not being immunized with routine childhood vaccines and maternal tetanus toxoid.

CONCLUSIONS

Predisposing risk factors can persistently impact immunization status despite improvements in immunization access in India. Tailored programmatic interventions should be developed to improve immunization coverage among those children and mothers who are at highest risk of being under-immunized or not immunized.

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

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

Hepatitis B vaccination for international travelers to Asia

There is a wide range in prevalence of hepatitis B virus (HBV) infection and HBV immunization programs between different regions. Hepatitis B is a vaccine preventable disease yet is still endemic in the majority of countries in Asia. Despite the decreasing global prevalence of chronic HBV infection, there is still considerable risk of HBV infection among international travelers to high endemic areas. Numbers of international travelers are expected to increase year by year; thus immunization among this cohort is a crucial preventive measure. Among international travelers to Asia, HBV immunization should be recommended for those without previous HBV vaccination who plan to travel to countries with intermediate to high prevalence of HBV, and especially for those individuals at greater risk of HBV infection; including travelers engaging in casual sex, getting a tattoo or piercing, and those having dental surgery or other medical procedures. Longer duration of travel is also associated with a greater risk of HBV infection. Travelers from low HBV prevalence countries, especially those born before implementation of universal HBV vaccination, might benefit from HBV vaccination during long-term traveling to HBV intermediate to high endemic country.

[Efficacy of hepatitis B immunoprophylaxis in children at high risk of hepatitis B and risk factors for mother-to-child transmission of hepatitis B virus]

OBJECTIVE

To investigate the risk factors for mother-to-child transmission of hepatitis B virus (HBV) and the efficacy of hepatitis B immunoprophylaxis in children at high risk of hepatitis B.

METHODS

A questionnaire survey was performed on 539 HBsAg-positive mothers and their 551 children (aged from 6 months to 5 years) at high risk of hepatitis B. Serum markers of hepatitis B in the children at high risk of hepatitis B were measured. Univariate logistic regression analysis was used to investigate the risk factors for mother-to-child transmission of HBV.

RESULTS

The rate of hepatitis B vaccination in the children at high risk of hepatitis B was 100%, and 96.6% received injections of hepatitis B vaccine and hepatitis B immunoglobulin (HBIG). The HBsAg positive rate showed no significant differences between different age groups. The HBsAb positive rate gradually decreased with the increasing age (P<0.01). The children born to HBsAg- and HBeAg-positive mothers had a significantly higher hepatitis B infection rate than those born to HBsAg-positive mothers (15.1% vs 0.2%; P<0.01). The high-risk children who received hepatitis B vaccination alone had a significantly higher hepatitis B infection rate than those who received both hepatitis B vaccine and HBIG injections (28.6% vs 2.8%; P<0.01).

CONCLUSIONS

The HBsAb positive rate gradually decreases with the increasing age in children at high risk of hepatitis B. Maternal HBsAg and HBeAg positivity and the absence of HBIG combined with hepatitis B vaccine injections for children at high risk of hepatitis B are the risk factors for mother-to-child transmission of HBV.

The Serum Anti-HBs Level Among Children Who Received Routine Hepatitis B Vaccination During Infancy in Mianyang City, China: A Cross-Sectional Study

Hepatitis B virus (HBV) prevalence has declined remarkably in children due to nationwide universal vaccination program for HBV in China. However, the persistence of immune response against HBV infection and the optimal time point when a booster vaccination should be performed remain to be elucidated. To assess the persistence and level of antibody against hepatitis B surface antigen (anti-HBs) in a representative population of age 15 and younger who received routine hepatitis B vaccination in Mianyang City, China. A cross-sectional study was conducted in 2011. One thousand five hundred twenty-six children of age 15 and younger who received three doses of 5 μg hepatitis B vaccine series during infancy but did not receive a booster vaccination later were enrolled. Of the 1,526 children, the mean age was 8.2 ± 4.1 and 739 children were male. The median anti-HBs level was 23.0 mIU/mL, and the total percentage of anti-HBs levels ≥10 mIU/mL was 60.9%. With an increase of age, median anti-HBs level, percentage of anti-HBs levels ≥10 mIU/mL, and percentage of anti-HBs levels ≥100 mIU/mL declined remarkably in the early period and reached the lowest level at the age of 3 and then remained relatively stable. The median anti-HBs level, the percentage of anti-HBs levels ≥10 mIU/mL, and the percentage of anti-HBs levels ≥100 mIU/mL in 1- and 2-year-old children were much higher than that in children aged 3-15 (p < 0.05, respectively). Immunity against HBV infection gradually decreased in early ages of children of 15 and younger who received three doses of 5 μg hepatitis B vaccine series during infancy in China. Three dosages of 10 μg hepatitis B vaccine for infants and repeated vaccination or additional booster vaccination for some children at or before age 3 should be provided to get much more powerful immunity to HBV.

Predictors of HVTN 503 MRK-AD5 HIV-1 gag/pol/nef vaccine induced immune responses

BACKGROUND

Phambili, the Merck (MRK)-Adenovirus Type 5 (Ad5) HIV-1 gag/pol/nef subtype B vaccine study, conducted in South Africa, suspended enrollment and vaccination when companion study, Step, was found non-efficacious. Although the vaccine did not prevent HIV-1 infection or lower viral-load setpoint, immune responses recognized clades B and C HIV-1 subtypes. We investigated predictors of the vaccine-induced antigen-specific immune responses.

METHODS

Vaccine-induced immunogenicity was ascertained by interferon-γ ELISpot assays on the first 186 enrolled participants receiving two vaccinations. Analyses, stratified by study arm/sex, were performed on baseline demographics [sex, age, Body Mass Index (BMI), site, Adenovirus Type-5 (Ad5) titer, Herpes Simplex Virus Type-2 (HSV2) status, heavy drinking]. Multivariate logistic regression determined predictors.

RESULTS

Of the 186 participants, 53.7% (n = 100) were female, median BMI was 22.5 [IQR: 20.4-27.0], 85.5% (n = 159) were Ad5 seropositive, and 18.8% (n = 35) drank heavily. All vaccine recipients responded to both clade B (n = 87; 47%) and/or C (n = 74; 40%), p = 0.17. In multivariate analysis, female sex [Adjusted Odds Ratio (AOR): 6.478; p = 0.0159], overweight/obese BMI (AOR: 0.186; p = 0.0452), and heavy drinking (AOR: 0.270; p = 0.048) significantly predicted immune response to clade C for any antigens. A marginally significant predictor of clade C-pol antigen was female sex (AOR: 3.182; p = 0.0500).

CONCLUSIONS

Sex, BMI, and heavy drinking affected vaccine-induced HIV-1 specific immune responses to clade C antigens. The role of female sex and overweight/obese BMI boosting and suppressing vaccine-induced HIV-1 specific immune responses, respectively, requires elucidation, including any effect on HIV vaccine efficacy, especially in the era of colliding epidemics (HIV and obesity).

Seroprevalence of hepatitis B in two period birth cohorts of Bolivian children: effect of universal vaccination

BACKGROUND

Since 2000 universal routine immunization against the hepatitis B virus (HBV) was implemented in Bolivia. This study aimed to assess the seroprevalence of markers against HBV in two different birth cohorts (pre-universal vaccine cohort and post-universal vaccine cohort) from Cochabamba, Bolivia.

METHODS

We performed a school-based seroepidemiological survey (n = 424) of HBV in 2010 in the Cochabamba region. An ELISA test was used to measure antibodies to the hepatitis B surface antigen (anti-HBs IgG) and to the hepatitis B core antigen (anti-HBc IgG).

RESULTS

The prevalence of anti-HBs IgG in the pre-universal vaccine cohort was 5.8% (95% CI: 3.3-8.3%); it was higher in boys (9.1%), and those living in suburbs (9.7%). The anti-HBs IgG prevalence among post-universal vaccine cohort was 37.9% (95% CI: 28.5-48.1%), and was higher in children who spoke Quechua at home (51.0%), those living in suburbs (53.9%), and those born in 2005 (72.7%). Neither cohort showed differences relating to parental education. The prevalence of anti-HBc IgG was 1.1% among post-universal vaccine cohort and 1.2% among pre-universal vaccine cohort (p > 0.05).

CONCLUSIONS

This study identified a persistent low seroprevalence of hepatitis B infection in spite of a decade of universal immunization, and low long-term humoral immunity against HBV infection in vaccinated children in Cochabamba. 

Hepatitis B and C infection in international travelers

BACKGROUND

Hepatitis B and C virus (HBV and HCV) cause significant morbidity and mortality worldwide. With the rise in international travel over the last three decades, many travelers are at risk of HBV and HCV infection.

METHODS

This review focuses on the epidemiology of HBV and HCV in international travelers, the modes of transmission, and the prevention of infection in travelers.

RESULTS

The risk of HBV and HCV infection varies widely and depends on the prevalence of the destination country, the duration of travel, and the activities undertaken while abroad. Travelers commonly undertake high-risk activities that place them at risk of both HBV and HCV infection. Poor uptake of preventative health measures and poor adherence to health recommendations are also common. The monthly incidence of HBV infection for long-term travelers to endemic countries ranges from 25 to 420 per 100,000 travelers. HBV infection can be prevented through timely vaccination of travelers. HBV vaccination is safe and efficacious with protective levels of antibodies achieved in >90% of recipients. Information regarding the risk of HCV acquisition is scarce and until recently was limited to case reports following medical interventions.

CONCLUSIONS

This review demonstrates international travelers are at risk of HBV and HCV infection and provides evidence-based information enabling health practitioners to provide more appropriate pre-travel advice. HBV vaccination should be considered in all travelers to countries with a moderate to high HBV prevalence (HBsAg ≥ 2%) and the risk and benefits discussed with the individuals in consultation with the health practitioner. There is no duration of travel without risk of HBV infection. However, it is apparent that those travelers with a longer duration of travel are at greatest risk of HBV infection (ie, expatriates). Travelers should also receive advice regarding the modes of transmission and the activities that place them at risk of both HBV and HCV infection.

Cost-effectiveness of augmenting universal hepatitis B vaccination with immunoglobin treatment

OBJECTIVE

To compare the cost-effectiveness of hepatitis B virus (HBV) control strategies combining universal vaccination with hepatitis B immunoglobulin (HBIG) treatment for neonates of carrier mothers.

METHODS

Drawing on Taiwan's experience, we developed a decision-analytic model to estimate the clinical and economic outcomes for 4 strategies: (1) strategy V-universal vaccination; (2) strategy S-V plus screening for hepatitis B surface antigen (HBsAg) and HBIG treatment for HBsAg-positive mothers' neonates; (3) strategy E-V plus screening for hepatitis B e-antigen (HBeAg), HBIG for HBeAg-positive mothers' neonates; (4) strategy S&E-V plus screening for HBsAg then HBeAg, HBIG for all HBeAg-positive, and some HBeAg-negative/HBsAg-positive mothers' neonates.

RESULTS

Strategy S averted the most infections, followed by S&E, E, and V. In most cases, the more effective strategies were also more costly. The willingness-to-pay (WTP) above which strategy S was cost-effective rose as carrier rate declined and was <$4000 per infection averted for carrier rates >5%. The WTP below which strategy V was optimal also increased as carrier rate declined, from $1400 at 30% carrier rate to $3100 at 5% carrier rate. Strategies involving E were optimal for an intermediate range of WTP that narrowed as carrier rate declined.

CONCLUSIONS

HBIG treatment for neonates of HBsAg carrier mothers is likely to be a cost-effective addition to universal vaccination, particularly in settings with adequate health care infrastructure. Targeting HBIG to neonates of higher risk HBeAg-positive mothers may be preferred where WTP is moderate. However, in very resource-limited settings, universal vaccination alone is optimal.

Successful tenofovir treatment for fulminant hepatitis B infection in an infant

Fulminant hepatic failure is defined by the presence of severe impairment of liver function, with or without encephalopathy, in patients with no underlying chronic liver disease. We report the case of a 4-month-old infant who developed fulminant hepatitis B infection and recovered concomitant with tenofovir therapy without liver transplantation.

Hepatitis B surface antigen-1018 ISS adjuvant-containing vaccine: a review of HEPLISAV™ safety and efficacy

Immunization represents the most effective approach to the prevention of hepatitis B virus infection and the long-term complications of chronic disease, including liver cancer and liver failure. Current vaccines require three doses to achieve maximal immunogenicity and fail to produce long-lasting protection in 5-10% of immune-competent individuals and in a much larger proportion of immune-compromised patients. Immunostimulatory DNA sequence (ISS) vaccine adjuvants, when combined with vaccine antigens, may increase immunogenicity and reduce the number of required doses to achieve this goal. 1018 ISS plus recombinant hepatitis B surface antigen has been demonstrated to achieve these goals in immune competent and vaccine-hyporesponsive populations without compromising recipient safety.

Scaling up human papillomavirus vaccination: a conceptual framework of vaccine adherence

This review article provides a conceptual framework for human papillomavirus (HPV) vaccine acceptance and adherence, with a focus on improving understanding of the sociocultural factors impacting vaccine adherence behaviour. We include a systematic review of the slowly expanding literature on HPV vaccine acceptability and uptake in developed nations, as well as the relatively few publications from poorer nations, where more than 80% of global cervical cancer related deaths occur and where the vaccine will probably have the largest impact. We suggest that this conceptual framework will not only improve our understanding of HPV vaccine uptake and adherence, but it may also guide future sociobehavioural research geared towards improving adherence to the HPV vaccine and other multi-step vaccines in a young population at risk for sexually transmissible infections.