Nationwide vaccination: a success story in Taiwan

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

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

Worldwide prevalence of hepatitis B virus and hepatitis C virus among patients with cirrhosis at country, region, and global levels: a systematic review

BACKGROUND

Empirical, updated country-level estimates on the proportion of cirrhosis attributable to viral hepatitis are required. We estimated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in patients with cirrhosis at country, regional, and global levels as an approximation for the fractions of cirrhosis attributable to viral hepatitis.

METHODS

In this systematic review, we searched MEDLINE, Embase, Web of Science, and Scielo between Jan 1, 1993, and Aug 1, 2021. Studies were eligible if they reported on the prevalence of both HBV and HCV infection in representative studies of at least 20 patients with cirrhosis. Studies were excluded if they used first-generation HCV assays or were from a selected population of patients with cirrhosis (eg, patients selected based on specific causes, veterans, injecting drug users). Two authors (CJA and CdM) selected and extracted aggregated data from the selected publications. Data were extracted for study recruitment period, age, sex, and cause of cirrhosis, among others. Data about heavy alcohol consumption and non-alcoholic fatty liver disease (NAFLD) were also extracted when available. Aggregated data from studies from key publications were requested from the authors of the original study if selection of patients was unclear or information on causes was missing. We estimated the country-specific prevalence of causes of cirrhosis by pooling study-level data from the same country using a random-effects model. Subsequently, we estimated the regional (WHO region and UN subregion) and global prevalence by weighting the country-specific prevalence by the number of new liver cancer cases that occurred in 2020, as estimated in GLOBOCAN. The study was registered with PROSPERO, CRD42020149323.

FINDINGS

Our database searches identified 21 338 records, and a further nine records were identified by scanning references of key publications. After excluding duplicates and assessing full-text articles for eligibility, 520 publications from 86 countries or territories (and reporting on 1 376 503 patients with cirrhosis) were included in the systematic review. The prevalence of HBV infection was lower among patients with cirrhosis in Europe, the Americas, and Oceania (UN subregional prevalence ranges 3-14%) than in Africa and Asia (8-61%). HCV infection prevalence was heterogenous, even within regions (12-83%). The combined prevalence of HBV and HCV infection exceeded 50% in most Asian and African regions. Globally, among patients with cirrhosis, 42% had HBV infection and 21% had HCV infection. The contribution of heavy alcohol use was highest in Europe (country range 16-78%), the Americas (17-52%), and Oceania (15-37%) and lowest in Asia (0-41%). Data on NAFLD were limited.

INTERPRETATION

HBV and HCV could account for almost two thirds of the global burden of cirrhosis. With the availability of effective interventions for the prevention or treatment of HBV and HCV, the data presented in this study will help to effectively allocate resources towards viral hepatitis elimination and to design interventions at the country level.

FUNDING

International Agency for Research on Cancer, World Health Organization.

Analysis of antiviral efficacy after switching from brand to generic entecavir in patients with treatment-naïve chronic hepatitis B

Background/Aims

Entecavir (ETV) can suppress chronic hepatitis B (CHB) virus replication as a standard of treatment drugs. For the treatment of CHB, affordable generic drugs may be more widely used in developing and undeveloped countries. However, there is little real-world data regarding the clinical efficacy of switching from entecavir-brand-name drugs (ETV-Brand) to entecavir generic drugs (ETV-Generic) with 0.5 mg once daily. The aim of the study was to evaluate the antiviral activity and safety of ETV-Generic in comparison to ETV-Brand in CHB-patients.

Methods

In this single-center, retrospective, 175 treatment-naïve—CHB-patients were assigned to receive 0.5 mg of ETV-Brand per day for a least 2 years and then switched to ETV-Generic for 6 months for analysis. The primary efficacy endpoint was a sustained virological response in comparison of the rate of undetectable serum Hepatitis B deoxyribonucleic acid (HBV DNA) as the sustained virologic response at baseline and 6 months after switching. Secondary efficacy endpoints were the comparison of the alanine aminotransferase (ALT) levels between before and after switching and ALT normalization. Renal safety consideration was reported on changing the estimated glomerular filtration rate.

Results

From baseline to 6 months, the rate of undetectable HBV DNA and ALT levels remained stable as compared ETV-Brand period with ETV-Generic for 6 months. The rate of undetectable HBV DNA were 81.1%in ETV-Brand versus 88.0%in ETV-Generic (p = 0.05 CI 0.1–13.5%). ALT levels were 27.2 IU/L (CI 24.8–29.6 IU/L) in ETV-Brand versus 26.2 IU/L (CI 24.0–28.4 IU/L) in ETV-Generic (p = 0.55). Both endpoints were not significantly different between ETV-Brand and ETV-Generic treatments. Kidney function did not significantly differ from ETV-Brand (80.8, interquartile range [IQR]: 66.6–95.3 mL/min/1.73 m²) to ETV-Generic treatment period (80.3, IQR: 65.6–93.5 mL/min/1.73 m²).

Conclusion

In treatment-naïve CHB-patients, the efficacy and safety profiles of switching from ETV-Brand to ETV-Generic showed no difference. Concluding the ETV-Generic comes to exciting virologic responses and rare adverse events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02317-7.

Hepatitis B and pertussis antibodies in 4- to 5-year-old children previously vaccinated with different hexavalent vaccines

In randomized active-comparator controlled studies, DTaP5-HB-IPV-Hib showed comparable immunogenicity and safety to other licensed vaccines. This study assessed persistence of anti-hepatitis B surface antigen (HBs) and anti-pertussis antibodies, when children were 4 to 5 years of age, 3 to 4 years after initial infant/toddler hexavalent vaccination. This was an extension of 2 European studies in which infants/toddlers received either DTaP5-HB-IPV-Hib or DTaP3-HB-IPV/Hib on a 2 + 1 or 3 + 1 schedule. Primary endpoints included percentages with anti-HBs ≥10 mIU/mL, and anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA), anti-pertactin (PRN), and anti-fimbriae types 2 & 3 (FIM) greater than or equal to the lower limit of quantitation (LLOQ). One month after 2 + 1 or 3 + 1 dosing, nearly all toddlers had anti-HBs ≥10 mIU/mL, and responded to the received pertussis antigens. Approximately 3 to 4 years later, 65.8%-70.2% in the DTaP5-HB-IPV-Hib and 82.0%-83.7% in the DTaP3-HB-IPV/Hib groups, respectively, had anti-HBs ≥10 mIU/mL. Percentages of children with pertussis antibodies above LLOQ after 2 + 1 dosing were 58.4% and 41.5% (anti-PT), 80.9% and 88.3% (anti-FHA), 66.1% and 72.6% (anti-PRN), and 94.4% and 3.3% (anti-FIM), in the DTaP5-HB-IPV-Hib and DTaP3-HB-IPV/Hib groups, respectively. This study demonstrated, as expected, waning of hepatitis B and pertussis antibodies during the 3 to 4 years after completion of a 3 + 1 or 2 + 1 hexavalent vaccination schedule. Nonetheless, anti-HBs levels ≥10 IU/mL and detectable antibodies against acellular pertussis antigens persisted in most study participants. The implications of these findings for the long-term prevention of hepatitis B and pertussis are further discussed.

Quantitative Hepatitis B Surface Antigen Predicts Hepatitis B Transmission in Infants Born to e Antigen-positive Mothers

GOALS

This study aimed to explore whether quantitative surface antigen [hepatitis B surface antigen (HBsAg)] can be used as a surrogate marker of hepatitis B virus (HBV) DNA to predict hepatitis B transmission before the first hepatitis vaccine dose in infants born to hepatitis B e antigen (HBeAg)-positive pregnant women.

BACKGROUND

Currently, HBV transmission persistently occurs worldwide, especially in infants born to e antigen (HBeAg)-positive highly viremic mothers. However, due to high cost, the extensive use of viral load testing to identify these high-risk mothers is limited.

MATERIALS AND METHODS

In total of 275 HBeAg-positive pregnant women paired with 280 infants were enrolled in this study. Quantitative HBsAg and HBV DNA levels were measured in the third trimester. Spearman rank correlation was used to assess the correlation between HBsAg levels and viral load, and multivariate logistic regression to identify factors related to HBV transmission in infants.

RESULTS

Among 280 infants included, 15 (5.4%) infants were infected with HBV. In this study, we observed that quantitative HBsAg was positively correlated with maternal viral load (r=0.70, P<0.001) and highly predicted HBV transmission in infants born to HBeAg-positive mothers with area under the curve of 0.76 (95% confidence interval, 0.71-0.81). The optimum threshold HBsAg levels above 4.6 log10 IU/mL to predict HBV transmission in infants had a sensitivity of 80.0%, specificity of 67.9%.

CONCLUSIONS

Quantitative HBsAg could be used as a surrogate marker of HBV DNA levels to predict hepatitis B transmission occurring before the injection of first-dose vaccine in infants born to e antigen-positive mothers.

Tumour virus vaccines: hepatitis B virus and human papillomavirus

Two of the most important human oncogenic viruses are hepatitis B virus (HBV) and human papillomavirus (HPV). HBV infection has been preventable by vaccination since 1982; vaccination of neonates and infants is highly effective, resulting already in decreased rates of new infections, chronic liver disease and hepato-cellular carcinoma. Nonetheless, HBV remains a global public health problem with high rates of vertical transmission from mother to child in some regions. Prophylactic HPV vaccines composed of virus-like particles (VLPs) of the L1 capsid protein have been licensed since 2006/2007. These target infection by the oncogenic HPVs 16 and 18 (the cause of 70% of cervical cancers); a new vaccine licensed in 2014/2015 additionally targets HPVs 31, 33, 45, 52, 58. HPV vaccines are now included in the national immunization programmes in many countries, with young adolescent peri-pubertal girls the usual cohort for immunization. Population effectiveness in women is now being demonstrated in countries with high vaccine coverage with significant reductions in high-grade cervical intra-epithelial neoplasia (a surrogate for cervical cancer), genital warts and vaccine HPV type genoprevalence. Herd effects in young heterosexual men and older women are evident. Cancers caused by HBV and HPV should, in theory, be amenable to immunotherapies and various therapeutic vaccines for HPV in particular are in development and/or in clinical trial.This article is part of the themed issue 'Human oncogenic viruses'.

[A plea for introduction of hepatitis B vaccination at birth in Côte d'Ivoire]

The Côte d'Ivoire National Immunization Technical Advisory Group 2015 work plan included elaboration of an opinion on inclusion of hepatitis B vaccination at birth in the Expanded Program on Immunization (EPI) in Côte d'Ivoire. A task force was set up to conduct this assessment according to a systematized method. The task force analysed scientific articles on the burden of hepatitis B in Côte d'Ivoire, the burden of mother-child transmission, the impact of hepatitis B vaccination at birth in countries which have adopted this strategy, the efficacy and safety of hepatitis B vaccine in newborns, the cost-effectiveness of hepatitis B vaccination at birth, and the best strategy to introduce hepatitis B vaccination at birth in the EPI. The National Immunization Technical Advisory Group of Côte d'Ivoire finally recommended introduction of a dose of hepatitis B vaccine at birth in the context of the Expanded Program on Immunization with maintenance of three doses of pentavalent vaccine (DPT-HepB-Hib) at 6, 10, and 14 weeks of age.

Changes in the Prevalence of HBsAg and HBeAg: a Study of 8696 Parturients in a Well Vaccinated Area

To elucidate the impact of a hepatitis B (HB) vaccination program on the prevalence of HB surface antigen (HBsAg) and HB envelope antigen (HBeAg) as well as the success rate of HBeAg clearance among parturients, we collected data on parturients who gave birth between 2000 and 2010, and recorded the HB status postpartum of those with positive HBeAg before birth. A total of 8696 parturients were enrolled, of whom 113 with prenatal positive HBeAg were invited back. The prevalence of HBsAg decreased over the study period, particularly in the vaccinated cohort, while there was no change in the prevalence of HBeAg. Foreign parturients had a higher HBeAg-positive rate and delayed HBeAg clearance, and those with a higher body mass index (>24 kg/m²) had earlier HBeAg clearance (51.9% vs. 23.9%, p = 0.005). Only 30% of the subjects who were positive for HBeAg before birth became negative 5 years after delivery. In conclusion, the downward trend in HB infection with more significance among vaccinated parturients reflects effective prevention and the impact of universal HB immunization. Nonetheless, aggressive follow-up is necessary for parturients who are persistently positive for HBeAg postpartum, as well as developing different public health policies for foreign parturients from endemic areas.

Clinical manifestations, course, and outcome of patients with neutralizing anti-interferon-γ autoantibodies and disseminated nontuberculous mycobacterial infections

Neutralizing anti-interferon-γ autoantibody (nAIGA)-associated immunodeficiency is an emerging medical issue worldwide. In the present study, we describe and discuss the clinical features and outcomes of patients with nAIGAs and disseminated infections by nontuberculous mycobacteria (dNTM).We thoroughly reviewed the medical records of all patients. Microorganisms and nAIGAs were identified using previously described methods with modifications. All data were calculated and analyzed using SPSS software.Among 46 adult patients with dNTM infections, we identified 45 cases (97.8%) with nAIGAs. The average patient age was 58.6 years, and there was no sex predominance. Cervical lymphadenitis (81.8%) was the most common clinical manifestation. Endocrine disorder was the leading comorbidity (7 cases). Malignancies were found in 4 patients, and all of the malignancies originated from the T-cell/macrophage lineage. More than half of the identifiable isolates were slow-growing NTMs. Twenty-eight (62.2%) and 18 (40.0%) patients had a history of zoster and salmonellosis, respectively. A high proportion of patients with recurrent episodes of NTM infection or a history of zoster and dNTM infection had initial nAIGA titers ≥10 dilution (P < 0.05). Twenty-seven patients (60.0%) required long-term antimycobacterial therapy and had at least 1 episode of recurrent NTM disease. No mortality was related to dNTM infection.In Taiwan, nAIGAs are a recently recognized mechanism of dNTM infection. Long term of antibiotic treatment and adherence to medical advice are necessary to improve the clinical outcome of patients with nAIGAs.

Prevention of hepatitis B virus infection: from the past to the future

About 3-5 % of the world's population is chronically infected by hepatitis B virus (HBV) and is at risk of developing liver cirrhosis or hepatocellular carcinoma. The risk of dying prematurely because of chronic HBV infection is higher in younger people. The current strategies to prevent HBV infection involve immunization (active and/or passive) and antiviral chemoprophylaxis. The vaccines available for active immunization, containing hepatitis B surface antigen, are safe and confer long-term immunity in most healthy subjects. Since the vaccination is unsatisfactory in some patients, e.g., those with chronic kidney disease, human immunodeficiency virus infection, type I diabetes mellitus, and celiac disease, new strategies of vaccination are required. The neonatal, infant, and adolescent routine program vaccination in about 180 countries has greatly decreased the disease burden. Passive immunization with specific HBV immunoglobulins is recommended after single acute exposure, in infants born to infected mothers, and in HBV-infected patients undergoing liver transplantation combined with nucleoside/nucleotide analogues (chemoprophylaxis). Chemoprophylaxis is also indicated in HBV carrier candidates for immunosuppressive treatment and in patients with occult B infection undergoing immunosuppressive therapy or hematopoietic stem cell transplantation. Since HBV is not eradicable by an immune response or by antiviral drugs developed so far, the only preventive strategy remains global neonatal vaccination in all countries, firstly in HBV-endemic countries.

Too much of a good thing? When to stop catch-up vaccination

During the 20th century, deaths from a range of serious infectious diseases decreased dramatically due to the development of safe and effective vaccines. However, infant immunization coverage has increased only marginally since the 1960s, and many people remain susceptible to vaccine-preventable diseases. "Catch-up vaccination" for age groups beyond infancy can be an attractive and effective means of immunizing people who were missed earlier. However, as newborn vaccination rates increase, catch-up vaccination becomes less attractive: the number of susceptible people decreases, so the cost to find and vaccinate each unvaccinated person may increase; in addition, the number of infected individuals decreases, so each unvaccinated person faces a lower risk of infection. This article presents a general framework for determining the optimal time to discontinue a catch-up vaccination program. We use a cost-effectiveness framework: we consider the cost per quality-adjusted life year gained of catch-up vaccination efforts as a function of newborn immunization rates over time and consequent disease prevalence and incidence. We illustrate our results with the example of hepatitis B catch-up vaccination in China. We contrast results from a dynamic modeling approach with an approach that ignores the impact of vaccination on future disease incidence. The latter approach is likely to be simpler for decision makers to understand and implement because of lower data requirements.

The potential of 1018 ISS adjuvant in hepatitis B vaccines: HEPLISAV™ review

Hepatitis B (HBV) virus infects the liver, and upon chronic infection, can cause liver cirrhosis and hepatocellular carcinoma. Despite universal vaccination programs against the virus, HBV still affects over 2 billion people worldwide, with over 240 million developing a chronic infection. While current alum-adjuvanted vaccines have shown efficacy in promoting seroprotection in healthy adults, 5-10% of immune-competent populations fail to achieve long-lasting seroprotection from these formulations. Furthermore, a large proportion of immunocompromised patients fail to achieve seroprotective antibody titers after receiving these vaccines. A novel vaccine candidate, HEPLISAV™, uses immunostimulatory sequences (ISS), in its formulation that helps induce a robust humoral and cell mediated immunity against HBV. In Phase III clinical trials, HEPLISAV™ has been shown to elicit seroprotective antibody titers with fewer immunizations. Similar safety profiles are demonstrated when compared with current HBV vaccines. For these reasons, HEPLISAV™ is an attractive vaccine to combat this global disease.

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.

Role of maternal viremia and placental infection in hepatitis B virus intrauterine transmission

The mechanism of intrauterine hepatitis B virus infection has not been established. In this study, venous blood, cord blood, and placental tissues from 171 chronic hepatitis B virus infected pregnant women were tested for hepatitis B surface antigen, hepatitis B core antigen, and hepatitis B virus DNA. We found that residence, mode of delivery, age, and number of gestational weeks of pregnant women were not correlated with intrauterine hepatitis B virus infection, while neonates of mothers who were hepatitis B s antigen positive and hepatitis B e antigen positive (P < 0.01) or who had high hepatitis B virus DNA levels (≥10(6) copies/ml) were more likely to get an intrauterine infection (P < 0.01). The hepatitis B virus infection rate in placental cell layers gradiently decreased from the mother's side to the fetus's side of the placenta, but the odds ratio value of correlation between placental hepatitis B virus infection and intrauterine infection gradiently increased. The way of intrauterine hepatitis B virus infection may be through a layer-layer transmission pathway, although the possibility of placental leakage cannot be excluded.

The efficacy and safety of antiviral therapy with lamivudine to stop the vertical transmission of hepatitis B virus

The purpose of this study was to investigate the efficacy and safety of lamivudine (LAM) in stopping the vertical transmission of hepatitis B virus (HBV). Pregnant women with normal alanine transaminase (ALT) (n = 100) and with abnormal ALT (n = 100) who were positive for hepatitis B e antigen (HBeAg), and with HBV DNA (deoxyribonucleic acid) levels ≥1.0 × 107 copies/ml were enrolled in this study. One hundred volunteers (50 with normal ALT, 50 with abnormal ALT) received 100 mg of LAM daily from the 24th to 32nd week of gestation and the untreated 100 volunteers served as controls. All infants received passive-active immunoprophylaxis. Compared to the control group, the study group got a marked reduction in serum levels (P < 0.001) and high negativity (P < 0.001) of HBV DNA before delivery. They also got normalization in ALT levels as much as controls received general medication (P > 0.05). The prenatal transmission rate in the study group was significantly lower than that of the control group (P < 0.05). There were no differences in incidences of congenital malformation between the two groups (P > 0.05). LAM treatment can effectively and safely stop vertical transmission of HBV and normalize the ALT levels of pregnant women.

Hepatitis B virus infection and pregnancy

Pregnancy only mildly affects that natural progression of acute and chronic infection by the hepatitis B virus (HBV) but it does bring to light three important questions. Mother to child (vertical) transmission risk is best prevented by mandatory HBs antigen testing in all pregnant women in their second trimester and by systemic serovaccination of newborns of infected mothers. In mothers with high viral load, vertical infection in utero could be prevented by lamivudine, telbivudine or tenofovir treatment. Invasive obstetric or gynecological procedures (such as amniocentesis, forceps, etc.) do not seem to increase the risk of vertical infection. Breastfeeding is not contraindicated in maternal HBV infection after serovaccination of the newborn. This holds true for mothers on active treatment with tenofovir which is not absorbed into breast milk. When it comes to managing active antiviral treatment, in absence of virosuppression with lamivudine, tenofovir remains a logical step-up treatment; in absence of virosuppression with adefovir, tenofovir also remains a logical step-up choice as do tenofovir/emtricitabine combinations or lamivudine in absence of preexisting resistance which may have been induced during combination treatment of adefovir and lamivudine. In cases of effective virosuppression with treatment by analogues, lamivudine should be continued and entecavir should eventually be replaced by lamivudine, telbivudine or tenofovir; adefovir should be replaced by tenofovir or lamivudine in absence of resistance (which would require tenofovir therapy) or adefovir which would restrict lamivudine therapy.

Immunogenicity and safety of a Haemophilus influenzae B (Hib)-hepatitis B vaccine with a modified process hepatitis B component administered with concomitant pneumococcal conjugate vaccine to infants

BACKGROUND

A hepatitis B vaccine was manufactured with a modified process (mpHBV) that incorporated double the usual amount of phosphate. Following a study in young adults, the mpHBV was evaluated in infants in a combination hepatitis B and Haemophilus influenzae B vaccine (mpHBV-Hib).

METHODS

The mpHBV-Hib was compared with the licensed bivalent HBV-Hib vaccine Comvax™ for immunogenicity and safety. Both vaccines contained 5 μg/0.5 mL of hepatitis B surface antigen (HBsAg) and 7.5 μg/0.5 mL of PRP-OMPC (polyribosylribitol phosphate outer membrane protein complex). A total of 543 infants were randomized 1:1 to receive either vaccine at 2, 4 and 12 months of age. A pneumococcal conjugate vaccine (PCV) was given concomitantly. Immunogenicity was assessed at 1-month post-dose 3.

RESULTS

Seroprotection rates [% subjects with anti-hepatitis B surface antigen antibody titers (anti-HBs) ≥10 mIU/mL)] were 100% and 99% for mpHBV-Hib and the licensed control (Comvax™), respectively. Anti-HBs geometric mean titers (GMTs) were 4204 (95% CI, 3411-5182) and 1683 (95% CI, 1350-2099) mIU/mL, respectively. Anti-PRP seroprotection rates (SPR) at ≥0.15 μg/mL and at ≥1.0 μg/mL were 97% and 94%, respectively, for mpHBV-Hib and 96% and 92%, respectively, for the control. Anti-PRP GMTs were 7.1 μg/mL for mpHBV-Hib and 8.0 μg/mL for the control. Reactogenicity of the two vaccines was similar.

CONCLUSIONS

The mpHBV in combination with Hib and with co-administered PCV was highly immunogenic. The safety profile of mpHBV-Hib was comparable to the licensed control. Both the control and mpHBV-Hib met acceptability criteria for seroprotection rates to hepatitis B, with higher anti-HBs GMTs noted for mpHBV-Hib.

A nested case-control study of maternal-neonatal transmission of hepatitis B virus in a Chinese population

AIM: To examine the determinants of maternal-neonatal transmission of hepatitis B virus (HBV).

METHODS: A nested case-control study was conducted in Changsha, Hunan, People’s Republic of China from January 1, 2005 to September 31, 2006. To avoid potential maternal blood contamination, we collected vein blood of newborns immediately after birth and before initial hepatitis B vaccination to determine the HBV infection status of the newborn. For each HBsAg-positive infant, one HBsAg-negative infant born to an HBsAg-positive mother was matched by hospital at birth (same), gender (same), and date of birth (within 1 mo). A face-to-face interview was conducted to collect clinical and epidemiological data. Conditional logistic regression analysis was used to estimate the independent effects of various determinants on maternal-neonatal transmission of HBV.

RESULTS: A total of 141 HBsAg-positive infants and 141 individually matched HBsAg-negative infants were included in the final analysis. Maternal first-degree family history of HBV infection, intrahepatic cholestasis, and premature rupture of membranes were risk factors for perinatal transmission of HBV, whereas systematic treatment and HBV immunoglobulin injections for mothers with HBV infection were protective factors for maternal-neonatal transmission of HBV, after adjustment for potential confounding factors.

CONCLUSION: For HBsAg-positive mothers, systematic treatment, HBV immunoglobulin administration, and controlling intrahepatic cholestasis and pregnancy complications may reduce the incidence of perinatal transmission of HBV.

Efficacy of the nationwide hepatitis B infant vaccination program in Taiwan

BACKGROUND

Taiwan launched a nationwide infant vaccination program for hepatitis B (HB) in 1984.

OBJECTIVES

This study evaluated the seroprevalence of hepatitis B virus (HBV) and the incidence of high alanine aminotransferase (ALT) level among young adults prior to, during, and since the introduction of the nationwide HBV vaccination program.

STUDY DESIGN

Researchers recruited 101,584 freshmen (male:female=1.114:1; mean age, 18.5±0.5 years) from 21 universities between 1995 and 2009 (birth cohorts 1977-1991) in Taiwan, testing for serum hepatitis B surface antigens (HBsAg), hepatitis e antigens (HBeAg), antibodies against HBsAg (anti-HBs), and liver function tests, including ALT and aspartate aminotransferase (AST).

RESULTS

The results showed that the prevalence of HBsAg decreased significantly from 14.3% in 1995 to 1.1% in 2009 and the seroprevalence of HBeAg decreased significantly from 5.9% in 1995 to 0.3% in 2009. Seroconversion to anti-HBs maintained a steady rate above 50% between 1995 and 2007, but declined considerably to 36.6% and 36.4% in 2008 and 2009, respectively. Subject with HBeAg seropositivity was in 43.94% of HBV carriers. Double seronegativity for HBsAg and anti-HBs was observed in 2007 (47.8%), 2008 (62.3%), and 2009 (62.5%). High ALT level was observed in 5.74% of the subjects, particular among HBV-carriers (16.5% of HBV carrier vs. 5.0% of non-HBV carrier; ORs, 3.733; 95% CIs, 3.463-4.023, p<0.0001). Subjects with high ALT level were significantly positively associated with HBeAg (10.5% of HBeAg seropositive vs. 1.9% of HBeAg seronegative; ORs, 6.195; 95%CI, 5.629-6.818; p<0.0001). Male subjects were more easily infected by HBV than female subjects were (HBsAg, ORs, 1.355, 95% CI, 1.283-1.431; HBeAg, ORs, 1.324, 95% CI, 1.218-1.439, p<0.0001), and significantly more male subjects had high ALT levels than female subjects did (ORs, 4.087; 95% CI, 3.819-4.375, p<0.0001).

CONCLUSIONS

The mass vaccination program successfully reduced the HBV carrier rate and prevalence of chronic hepatitis B in Taiwan. However, the low percentage of anti-HBV in 2008 and 2009 remains unresolved.

Correlation between maternal hepatitis B surface antigen carrier status with social, medical and family factors in an endemic area: have we overlooked something?

PURPOSE

Hepatitis B virus (HBV) infection is endemic in many countries, but the risk factors for HBV carriage in the obstetric population are unclear.

METHODS

A survey on 1,580 women attending the antenatal clinic in an endemic region was conducted in order to examine the prevalence of and factors associated with maternal HBV carriage, including socio-demographic, medical, and previous obstetrical and family history, by means of a questionnaire.

RESULTS

The prevalence of maternal HBV carriage was 9.1%, and 4.8% of women with a history of hepatitis B vaccination were found to be HBV carriers. Factors associated with maternal HBV carriage were residency status (adjusted odds ratio [aOR] 3.65 for immigrants; aOR 7.62 for non-residents), positive family history (aOR 3.72 for infected mother; aOR 5.36 for other family members), no previous vaccination (aOR 4.39) and having previous HBsAg testing (aOR 2.26).

CONCLUSIONS

The findings suggest that there was probably an overlooked role of horizontal transmission within the family setting in addition to perinatal transmission in determining the likelihood of HBV infection in our obstetric population. Reconfirmation of hepatitis B status might be necessary among individuals with a history of vaccination to ensure the effectiveness of their immunoprotection.

Waning immunity and booster responses in nursing and medical technology students who had received plasma-derived or recombinant hepatitis B vaccine during infancy

BACKGROUND

The national hepatitis B virus (HBV) vaccination program was launched in Taiwan in 1984. After November 1992, a recombinant HBV vaccine replaced the plasma-derived HBV vaccine.

METHODS

A total of 1,812 nursing and medical technology freshman students was tested to evaluate their waning immunity toward hepatitis B. In the 2007 (2008) academic year, 438 (382) students testing nonprotective antibodies received 3 (1) booster doses of HBV vaccine according to suggestions from Taiwan's Center for Disease Control (CDC).

RESULTS

The seroprevalences of hepatitis B surface antigen (+) were 0.8% and 0.7% in the plasma-derived and recombinant group, respectively; for antibody to hepatitis B surface antigen (anti-HBs) (+), they were 43.2% and 33.3% (P < .001), respectively. In the 2007 freshman group, 99.1% of the students previously vaccinated with plasma-derived HBV vaccine exhibited anti-HBs seroconversion. In the 2008 freshman group, the booster dose induced anti-HBs seroconversions of 92.1% and 95.9% in the students who had received the plasma-derived and recombinant HBV vaccine, respectively (P = .370).

CONCLUSION

Most students exhibited signs of immune memory after receiving the booster, regardless of having received plasma-derived or recombinant HBV. Only a small number of vaccinees lost their immune memory after 16 years, suggesting that some students might benefit from boosting before proceeding to clinical practice.

Hepatitis B virus infection and risk of intrahepatic cholangiocarcinoma and non-Hodgkin lymphoma: a cohort study of parous women in Taiwan

Few studies have evaluated the risk of cancers other than hepatocellular carcinoma associated with hepatitis B virus (HBV) infection. This study aimed to estimate incidence rates of intrahepatic cholangiocarcinoma (ICC) and non-Hodgkin lymphoma (NHL) and its major subtypes in a nationwide cohort of parous women and to assess their associations with chronic HBV infection. We conducted a cohort study including 1,782,401 pregnant Taiwanese women whose HBV serostatus was obtained from the National Hepatitis B Vaccination Registry. Newly diagnosed ICCs and NHLs were ascertained through data linkage with the National Cancer Registry. Risks of ICC and NHL were assessed using Cox proportional hazards regression models. After a mean of 6.91 years of follow-up, there were 18 cases of ICC and 192 cases of NHL, including 99 cases of diffuse large B-cell lymphoma (DLBCL). Incidence rates of ICC were 0.09 and 0.43 per 100,000 person-years, respectively, among women who were hepatitis B surface antigen (HBsAg)-seronegative and HBsAg-seropositive, showing an age-adjusted hazard ratio (HR(adj) ) (95% confidence interval [CI]) of 4.80 (1.88-12.20). The incidence rates of NHL overall for HBsAg-seronegative and HBsAg-seropositive women were 1.23 and 3.18 per 100,000 person-years, respectively, with an HR(adj) (95% CI) of 2.63 (1.95-3.54). Among NHL subtypes, HBsAg-seropositive women had an increased risk of DLBCL compared with those who were HBsAg-seronegative (incidence rates: 1.81 and 0.60 per 100,000 person-years, respectively; HR(adj) [95% CI]: 3.09 [2.06-4.64]). The significantly increased risk was not observed for other specific subtypes of NHL.

CONCLUSIONS

Chronic HBV infection was associated with an increased risk of ICC and DLBCL in women. Our data suggested a possible etiological role of HBV in the development of ICC and specific subtypes of NHL.

Adult T-cell leukemia/lymphoma in Taiwan: an analysis of 17 patients and review of the literature

AIM

We reviewed our experience with adult T-cell leukemia (ATL), describing the clinical manifestations and outcome in order to facilitate case recognition in the future.

METHODS

We retrospectively reviewed the charts of 17 patients with ATL diagnosed from January 1996 to September 2009 at Mackay Memorial Hospital, Taipei, Taiwan.

RESULTS

The overall survival of the whole study group was 138 days. The medial survival of the 10 patients who received chemotherapy is 204 days. The other six patients who did not receive any chemotherapy had a median survival of 28 days. The co-infection rate with HTLV-1 and HBV or HCV is 47% and 35% respectively.

CONCLUSION

ATL in Taiwan is a rare malignant T-cell lymphoma with a very poor prognosis. Our series raised the interesting possibility of an association with chronic hepatitis B or C.

Survey of HBsAg-positive pregnant women and their infants regarding measures to prevent maternal-infantile transmission

BACKGROUND

Intrauterine infection is the main contributor to maternal-infantile transmission of HBV. This is a retrospective study of 158 HBsAg-positive pregnant women who delivered children from Jan 1st, 2004 to Dec.31th, 2006 in Wuhan City, China. We investigated the measures taken to prevent maternal-infantile transmission of hepatitis B virus and the infection status of children.

METHODS

HBsAg-positive pregnant women were selected by a random sampling method when they accepted prenatal care in district-level Maternal and Child Health Hospitals. On a voluntary basis, these women completed questionnaires by face-to-face or phone interviews. The collected data were used to evaluate the immunization programs that pregnant women had received for preventing hepatitis B maternal-infantile transmission.

RESULTS

Among the 158 women, 143(90.5%) received Hepatitis B immune globulin during pregnancy, and 86.0% of their children were given Hepatitis B immune globulin and Hepatitis B vaccine. The rate of cesarean section was 82.3%, and 28.5% of these were aimed at preventing HBV infection. The rate of bottle feeding was 51.9%, and 89.0% of bottle feeding cases were for the purpose of preventing HBV infection. There were 71 cases of participants who were HBeAg-positive. Compared with the HBsAg+ HBeAg- group (only HBsAg-positive), the HBsAg + HBeAg+ group (HBsAg-positive and HBeAg-positive) had significantly higher rates of the caesarean section and bottle feeding resulting from hepatitis B (P < 0.05). Five cases were HBsAg-positive by Umbilical Cord Blood detection. The intrauterine infection rate of newborns was 6.7%. The chronic HBV rate of children was 4.0%.

CONCLUSION

Most HBsAg positive pregnant women have a growing awareness of maternal-infantile transmission of Hepatitis B virus and are receiving some form of preventative treatment, like combined immunization. Caesarean and bottle feeding are very common, often primarily to prevent transmission. Relatively few intrauterine infections were identified in this sample, but many infants did not appear to seroconvert after vaccination.

Epidemiology of hepatitis B and C viruses: a global overview

This article reviews the prevalence, disease burden, genotype distribution, and transmission patterns of hepatitis B virus (HBV) and hepatitis C virus in the 6 World Health Organization regions. The global epidemiology of hepatitis B and C demonstrates a predominantly declining prevalence of the diseases. Improvement in the control of hepatitis B has been largely achieved with implementation of a more universal HBV vaccine program, although a large gap still remains in the effort toward global prevention of hepatitis B. The transmission of hepatitis C has been greatly impacted by mandatory screening of blood donors in most countries in the world, although intravenous drug use continues to be a major source of infection. Public education regarding the risks of exposure to infected paraphernalia as well as household items such as razors is necessary in the continuing effort to curb this disease.

Prevention of hepatocellular carcinoma in hepatitis B virus infection

Chronic hepatitis B is the main risk factor for hepatocellular carcinoma (HCC) in Asia. The most important preventive strategy's adoption of the universal hepatitis B vaccination program is now in its third decade. There is a clear reduction in both chronic hepatitis B virus (HBV) infection (hepatitis B surface antigen "carriage") but also in childhood HCC in Taiwan. An outstanding concern is variability in vaccine coverage between countries. For patients with chronic hepatitis B, serum HBV DNA levels have emerged as the key risk factor for development of HCC. The initial treatment for chronic hepatitis B was interferon. One randomized control trial, and several case-control or cohort studies have shown benefits for preventing HCC, particularly in cirrhotic patients who responded to therapy. With nucleos(t)ide analogs, the most important study has been the Asian Cirrhosis Lamivudine multicenter randomized controlled trial. This showed that lamivudine can reduce disease progression in HBV-related cirrhosis, including an approximately 50% decrease in HCC incidence. Such efficacy was achieved despite emergence of drug resistance in approximately 50% of cases. Case-control studies have suggested that hepatitis B cases without cirrhosis may also benefit. In conclusion, it is now possible to prevent HBV-related HCC. The most effective method is hepatitis B vaccination, which prevents chronic HBV infection and chronic liver disease resulting therefrom. Interferon therapy appears to confer benefit but the evidence is weaker. First-generation oral antiviral (lamivudine) reduces HCC risk, particularly in cirrhotics. Long-term outcome data with newer, more potent HBV antivirals that have a higher genetic barrier to drug resistance are eagerly awaited.

Chronic hepatitis B infection in an Australian antenatal population: seroprevalence and opportunities for better outcomes

BACKGROUND

In the antenatal population, screening for Hepatitis B virus (HBV) carrier status is routinely undertaken to guide preventative measures for the newborn. There is scarce information in the literature, however, regarding the subsequent management of Hepatitis B surface antigen (HBsAg) positive mothers.

AIMS AND METHODS

Thus, we undertook this retrospective study to (i) determine the prevalence of HBsAg positivity among mothers attending two teaching hospital birth centers; (ii) determine whether HBsAg mothers received HBV education and underwent further evaluation of HBV infectivity status; and (iii) determine whether these mothers had further follow up for HBV infection post delivery.

RESULTS

Between January 2003 and December 2006, 14, 857 mothers were screened for hepatitis B virus infection. Among these, 295 mothers were positive with HBsAg seroprevalence of 2%. A more detailed review of the available 206 medical records revealed that the majority (78%) had previous documentation of infection in earlier pregnancies. However none had received education regarding HBV infectivity. In addition, liver function tests were only performed in 78% of the mothers while Hepatitis B e antigen was tested in 65% of cases. Further, 93% of the mothers had no documentation of further follow up plans or referrals for their HBV infection.

CONCLUSION

It is clear that chronic HBV infection is prevalent in the antenatal population. However, there are no strategies to ensure that infected mothers subsequently undergo further education for HBV or evaluation of infectivity. Clearly strategies are required to ensure improved follow up of hepatitis B infected mothers.

Long-term protection of hepatitis B vaccine 18 years after vaccination

INTRODUCTION

This is the third evaluation study of the hepatitis B virus (HBV) vaccination program, initiated in 1989 in Saudi Arabia.

AIMS

This study sought to assess the efficacy and long-term protection of the hepatitis B vaccine among Saudi adolescents.

METHODS

School students between the ages of 16 and 18 years were randomly chosen from high endemic (Aseer), intermediate endemic (Madinah), and low endemic (Al-Qaseem) areas of the country. Hepatitis B surface antigen (HBsAg), hepatitis B core IgG antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) were measured using standard techniques.

RESULTS

A total of 1355 students (689 males and 666 females) were selected randomly from the three areas. No cases of positive HBsAg or anti-HBc were detected among the study population. Five hundred and ten students (38%) showed protective anti-HBs titers (>/= 10mIU/ml), while 528 (39%) students had undetectable anti-HBs titers (<1 mIU/ml).

CONCLUSIONS

This study shows the excellent efficacy of the HBV vaccination program in Saudi Arabia 18 years after its launch. Based on this study and others, a booster dose for the adult population appears to be unnecessary.

Review of hepatitis B surface antigen-1018 ISS adjuvant-containing vaccine safety and efficacy

Existing hepatitis B virus (HBV) vaccines produce seroprotective titers in > 90% of healthy adult recipients following 3 doses administered over 6 months. The durability of this response is variable. Vaccine efficacy is greatly diminished in immune compromised patients. Given the high worldwide prevalence and burden of disease produced by chronic HBV infection, vaccines capable of producing high rates of durable seroprotective HBV surface antibody titers are required. Immunostimulatory sequences (ISS) containing repeating sequences of cytosine phosphoguanosine (CpG) dinucleotide motifs have emerged as useful tools for modulating immune responses. Dynavax Technologies produced a synthetic oligodexynucleotide (ODN) containing these motifs, resulting in an unmethylated cytosine and phosphoguanosine ODN called 1018 ISS. Dynavax's hepatitis B virus vaccine HEPLISAV is comprised of 1018 ISS mixed with recombinant hepatitis B surface antigen. Clinical trials, to date, have shown that HEPLISAV produces rapid, high titer, sustained seroprotection in healthy adults and vaccine hyporesponsive populations. Although additional supporting data are required, this represents a promising strategy to facilitate worldwide HBV prevention efforts.

What influences government adoption of vaccines in developing countries? A policy process analysis

This paper proposes a framework for examining the process by which government consideration and adoption of new vaccines takes place, with specific reference to developing country settings. The cases of early Hepatitis B vaccine adoption in Taiwan and Thailand are used to explore the relevance of explanatory factors identified in the literature as well as the need to go beyond a variable-centric focus by highlighting the role of policy context and process in determining the pace and extent of adoption. The cases suggest the feasibility and importance of modeling 'causal diversity'-the complex set of necessary and sufficient conditions leading to particular decisional outcomes-in a broad range of country contexts. A better understanding of the lenses through which government decision-makers filter information, and of the arenas in which critical decisions are shaped and taken, may assist both analysts (in predicting institutionalization of new vaccines) and advocates (in crafting targeted strategies to accelerate their diffusion).

Seroprevalence of HBV in immigrant pregnant women and coverage of HBIG vaccine for neonates born to chronically infected immigrant mothers in Hsin-Chu County, Taiwan

This study was carried out to assess the prevalence of HBsAg positivity and coverage rate of antenatal HBV screening among immigrant women. In addition, the extent of administration of HBIG plus HB vaccine #1 to neonates born to chronically infected (HBeAg-positive/HBsAg-positive) mothers was assessed. All pregnant women residing in Hsin-Chu County, Taiwan and giving birth during 2004-2006 were recruited. Among all 16926 cases, the prevalence of HBsAg positivity according to their ethnicities was Mainland Chinese, 11.0% (68/616); Indonesian, 3.5% (15/426); Vietnamese, 7.4% (42/568); aboriginal Taiwanese, 20.6% (109/530); and non-aboriginal Taiwanese 11.5% (1536/13368). Among the HBsAg carriers, the prevalence of HBeAg positivity was Mainland Chinese, 52.9% (36/68); Indonesian, 53.3% (8/15); Vietnamese, 45.2% (19/42); aboriginal Taiwanese, 47.7% (52/109); and non-aboriginal Taiwanese, 26.8% (411/1534). With non-aboriginal Taiwanese as the reference category, results of multiple logistic regression revealed the healthy immigrant phenomenon in the HBsAg carriage state among pregnant women from Indonesia (OR 0.30; CI 95%: 0.18-0.50) and Vietnam (OR 0.68; CI 95%: 0.49-0.93). On the contrary, among chronically infected mothers, Mainland Chinese showed the highest risk for HBeAg positivity (OR 2.79; CI 95%: 1.7-4.58). More efforts should be made to improve HBV infection among aboriginal Taiwanese pregnant women who were more vulnerable to HBsAg positivity (OR 2.15; CI 95%: 1.72-2.68) and HBeAg positivity (OR 1.93; CI 95%: 1.28-2.90). Age was another independent predictor for HBsAg positivity (OR 1.02; CI 95%: 1.01-1.03) and for HBeAg positivity among chronically infected mothers (OR 0.93; CI 95%: 0.91-0.96). The coverage rates of antenatal HBV screening and HBIG plus HB vaccine #1 showed no difference among these multiple ethnic subgroups. In 2006, the overall coverage rate of antenatal HBV screening was 98.7% (5546/5639), with the individual rate being Mainland Chinese, 100% (267/267); Indonesian, 97.2% (106/109); Vietnamese, 99.5% (201/202); aboriginal Taiwanese, 97.0% (196/202); and non-aboriginal Taiwanese, 99.8% (4776/4785). The administration rate of HBIG plus HB vaccine #1 was 100% for all ethnic subgroups.

An evaluation of the efficacy of the national immunization programme for hepatitis B

We report an evaluation of the Israeli national immunization programme for hepatitis B in the Haifa subdistrict. We used a convenience sample of blood tests reported positive for HBsAg over a 6-year period from children who were born after routine immunization began in 1992. We identified 11 children with presumed chronic hepatitis B virus infection who were residents of the Haifa subdistrict, three of whom were born in Israel. All three were immunized at the appropriate age and are thus considered vaccination failures rather than failure to vaccinate. The remaining eight were born abroad, had emigrated to Israel as children and were not immunized at birth. We estimate the rate of chronic hepatitis B virus infection for children born since 1998 to be 0.24/10,000 births. For all children resident in the subdistrict under the age of 12 years, the period prevalence is estimated to be 1.26/10,000. The rate of chronic infection in children younger than 12 years was significantly less than that of older cohorts and less than that of historical controls before the start of immunization. Although the reported rates are probable underestimates of actual rates, the fact that they are based on testing carried out in clinical settings increases the likelihood of positive findings and thus reduces the degree of error. The fact that most young carriers are foreign born points to the importance of timely catch-up programmes. In countries with low and intermediate rates of chronic infection, serosurveys of immunized children need to be large and are therefore costly. Monitoring HBsAg positive tests from routine testing carried out in clinical settings is an inexpensive way to monitor chronic infection rates.

[Prevention of cervical cancer (II): prophylactic HPV vaccination, current knowledge, practical procedures and new issues]

Despite the considerable success of early screening for prevention of cervical cancer, Pap smears have not fulfilled the hopes that it would lead to a large-scale reduction of this cancer's incidence. Screening appears to be useful for a tiny portion of the world population, although a relatively large portion must put up with its limitations and disadvantages. Human papilloma viruses (HPV) 16 and 18 are responsible for two thirds of all cervical cancers worldwide. The condylomata (condyloma acuminatum), or genital warts, induced by HPV 6 and 11 are frequent among the young and difficult to manage. The extent and burden of HPV infection are considerable, as is the psychological and emotional impact of the diseases associated with it. Because cancer of the cervix is the final consequence of chronic HPV infection, it can be prevented by vaccination. A prophylactic vaccine to protect against the precancerous and cancerous lesions associated with HPV should save lives, reduce expensive diagnostic and therapeutic interventions, and have substantial individual and collective benefits. Clinical trials of anti-HPV vaccines for the prevention of cervical cancer and condyloma have shown remarkable results and an efficacy unequaled in the history of vaccination against infectious diseases. Vaccine efficacy has been shown only in young girls never exposed to the virus and only for the lesions associated with the specific viral types in the vaccine. Preliminary data indicate that the vaccination is effective in women who have previously eliminated naturally the virus. It has no therapeutic effects on existing lesions or in healthy virus carriers. Practical questions remain to be resolved. If the vaccination is left to individual initiative and vaccination coverage is insufficient, there will be no perceptible reduction in the frequency of cervical cancer. Vaccination policies will not be identical in poor countries, where the disease represents one of the leading causes of mortality among women, and in the rich countries, where screening programs have considerably reduced the frequency of this cancer. Current planning calls for the introduction of systematic vaccination of young girls aged 9-15 years, with progressive "catch-up" vaccination of the cohorts of young women aged 16-26 years. Nonetheless mathematical models and immunogenicity results indicate a possible benefit for individual vaccination of adults. This approach must still be assessed in the clinical trials underway. Because the vaccine does not protect against all types of HPV associated with cervical cancer, screening must be continued according to the conditions currently set. Vaccination and screening, which are complementary and synergistic, now constitute the new standards for prevention of this disease.

Trend in incidence of hepatitis B virus infection during a decade of universal childhood hepatitis B vaccination in Saudi Arabia

Since 1990, the national strategy to eliminate hepatitis B virus (HBV) infection in Saudi Arabia has included universal administration of HBV vaccine to all infants. From 1990 to 1995 this vaccine was also routinely administered to children at school entry. The prevalence of hepatitis B surface antigen (HBsAg) among children before this programme was reported to be 6.7%. The objective of this study was to describe the trend in incidence of HBV infection over a decade of surveillance following the introduction of this programme. From January 1990 to December 1999 a total of 30,784 cases of HBV infection (positive for HBsAg) were reported. The total number of HBV infections among children <15 years of age was 4180 cases, with a prevalence of 0.05%. The total number of HBV infections among adults was 26,604 cases, with a prevalence of 0.22%. The prevalence varied by region, ranging from 0.03% to 0.72% with a mean prevalence of 0.15%. There was a clear decline in incidence among children whereas the incidence in adults slightly rose, perhaps owing to population growth estimated to be 3.3% annually. This study showed that the universal childhood HBV vaccination programme had an enormous positive impact on HBsAg seroprevalence among children in Saudi Arabia.

Prévention du cancer du col utérin : enjeux et perspectives de la vaccination antipapillomavirus

Cervical cancer remains a critical public health problem that is second only to breast cancer in overall disease burden for women throughout the world. In spite of the success of cervical cancer screening, Pap cytology screening is yet to be effectively implemented or has failed to reduce cervical cancer rates to an appreciable extent. Screening appears to benefit only a small fraction of women although a much larger percentage endures the inconvenience of the Pap test in order to avoid cervical cancer. The establishment of Human Papillomavirus (HPV) infection as the necessary cause of cervical precancers and cancers provides a tremendous opportunity for cervical cancer prevention through vaccination. HPV 16 and 18 which cause 70% of cervical cancers worldwide. Thus a prophylactic vaccine to prevent HPV related precancerous lesions and cancers would save lives, reduce the need for costly medical procedures and provide both women and communities throughout the world with substantial benefits. Based on the induction of neutralizing antibodies by non infectious Virus Like Particles (VLP) of L1 capside protein, prophylactic HPV vaccines have consistently induced high titter of neutralizing antibodies with minimal side effects and induce more than 90% protection from persistent HPV 16-18 infection and HPV 16 and 18 associated high-grade Cervical Intraepithelial Neoplasia (CIN) in proof of concept efficacy trials. HPV 16-18 vaccination will prevent HPV16-18 incident infection, and subsequently decrease in 90% the frequency of abnormal Pap attributable to these types and in about 50% overall abnormal Pap. HPV vaccination will reduce the number of women who require colposcopy, biopsy and cervical treatment for precancerous cervical lesions. The level of protection from death due to cervical cancer could exceed 95%. Three large phases prophylactic HPV VLP trials are now in progress and will form the basis for licensing of candidate vaccines in 2006. HPV vaccination targeting young female adolescents, aged 11 to 16 years, with a catch-up of those aged 17-25 years, would be a strategy to be addressed. Cervical cancer screening strategies, that will be cost-effective for the proper surveillance of women protected by HPV vaccination, are under analysis.

Comparison of the safety and immunogenicity of hepatitis B virus surface antigen co-administered with an immunostimulatory phosphorothioate oligonucleotide and a licensed hepatitis B vaccine in healthy young adults

BACKGROUND

Many individuals do not respond to a three-dose series of hepatitis B vaccine (HBV) and most do not achieve a protective antibody response until after dose 2 or 3.

METHODS

Healthy, seronegative 18-28 year old adults were randomly assigned in equal numbers to receive two doses of the experimental vaccine (HBV-ISS without alum) (0, 8 weeks) and placebo (24 weeks) or Engerix-B (0, 8, 24 weeks). Adverse events were collected during the first week and at 4 weeks after each injection. Antibodies were measured 4 weeks after dose 1; before, 1 and 4 weeks after dose 2, and before, 1 and 4 weeks after dose 3 and at 1 year.

RESULTS

Ninety-nine participants were enrolled (65% female; mean age 22.6 years). 79% of HBV-ISS and 12% of Engerix-B recipients had a protective antibody response 4 weeks post dose 1 (geometric mean concentration [GMC] 23.0 and 1.87 mIU/mL, respectively). By 1 week post dose 2, 100% of HBV-ISS and 18% Engerix-B recipients had protective levels (GMC 1603 versus 2.40 mIU/mL). Rates of adverse events were low and similar in both groups; headache and fatigue were the most common systemic adverse events in up to 1/3 of both groups. Mild injection-site tenderness was more common after HBV-ISS than Engerix-B after both doses (74-77% compared to 34-58%; p<or=0.029).

CONCLUSIONS

Protective levels are achieved more quickly and after fewer doses of HBV-ISS than Engerix-B. HBV-ISS is well tolerated but associated with more mild injection-site tenderness than Engerix-B.

Clinical Characteristics and Prognosis of Pediatric Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a rare pediatric malignancy that is usually advanced at diagnosis, with a relatively poor prognosis. Extensive treatment, including complete tumor resection, is believed to be necessary for cure. This study was performed to analyze treatment results and to search for prognostic factors of pediatric HCC.

METHODS

Between March 1982 and February 2004 a total of 16 children had been diagnosed as having HCC in our institution, and a retrospective analysis was performed.

RESULTS

The median age at diagnosis was 10.5 years, and the male/female ratio was 11:5. As a predisposing condition, hepatitis B virus (HBV) infections were present in 11 (68.8%) and liver cirrhosis in 8 (50.0%). Including 1 patient with a liver transplant, 4 patients (25.0%) underwent a primary operation with complete tumor resection, and 11 (68.8%) received neoadjuvant chemotherapy because of their inoperable state at diagnosis. After neoadjuvant chemotherapy, complete tumor resection was performed in four (36.4%). Thus complete resection was undertaken in a total of eight patients (50.0%). The estimated 5-year survival rate of all patients was 27.3%. The 5-year survival rate for patients who underwent complete tumor resection was 62.5%, and for those who underwent palliative resection or no operation it was 0%. The statistically significant prognostic factors were tumor stage, presence of metastasis, and complete tumor resection.

CONCLUSIONS

This study confirmed that complete tumor resection is essential for cure in pediatric patients with HCC, and neoadjuvant chemotherapy improves the tumors' resectability.

Characterization of HPV genotype profile in squamous cervical lesions in Portugal, a southern European population at high risk of cervical cancer

A different prevalence of human papillomavirus (HPV) types has been reported in distinct populations. Although Portugal has a relatively high incidence of cervical cancer within the European Union, no studies have been reported in the Portuguese population. Recently, a clinical trial using a vaccine targeted against HPV-16 demonstrated a high efficacy in preventing HPV-16 cervical lesions. The aim of the present study was the characterization of HPV genotype profile in squamous intraepithelial lesions (SIL) and invasive cervical cancer (ICC) from 608 patients using polymerase chain reaction (PCR) methodology. We frequently detected HPV-6/11 and HPV-16 in low-grade SIL (HPV-6/11, 18.9%; HPV-16, 44.2%). In high-grade SIL, HPV-16 was demonstrated in 74.2% of those lesions and in 80.0% of the cases with ICC. HPV-18 was found in 3.1%, 0.8% and in 15.0% of low, high SIL and ICC, respectively. The overall prevalence of multiple infections with high-risk HPV was 7.2%. Other types of HPV were detected in 7.0% of all cases. Our results demonstrate a high prevalence of HPV-16 in SIL and ICC in Portuguese women. Therefore, a prophylactic HPV-16/18 vaccine may be effective in the prevention of cervical cancer in a significant number of women from this southern European population.

Long-term efficacy of hepatitis B vaccine, booster policy, and impact of hepatitis B virus mutants

The long-term efficacy of hepatitis B vaccine, long-term effectiveness of hepatitis B immunisation programmes, immune memory induced by hepatitis B vaccine, current booster policies, and impact of hepatitis B virus mutants on immunisation programmes were reviewed at the Viral Hepatitis Prevention Board (VHPB) meeting in Sevilla, Spain, March 2004. The main focus was on universal vaccination programmes with data being presented from Italy, Saudi Arabia, Singapore, Spain, Taiwan, Thailand, The Gambia, and USA (Alaska).

A virus-based vaccine may prevent cervical cancer

High-risk human papillomaviruses (HPVs) are now recognized as the etiologic agents of invasive cervical cancer, a major cancer in women. A single HPV type (type 16) is responsible for about 50% of the cancers. The major capsid protein of papillomaviruses, L1, when expressed by recombinant DNA technology, has the intrinsic ability to assemble into virus-like particles (VLPs). In a recent study, a vaccine based on HPV 16 VLPs was tested in a placebo-controlled proof-of-principle trial in young women in the United States. The vaccine was found to prevent 100% of incident persistent HPV 16 infections and HPV 16-associated cervical intraepithelial neoplasia. These results offer promise that cervical cancer will be preventable by an HPV-based vaccine. Studies planned or in progress are examining the efficacy of the vaccine in men, in HIV-infected individuals, and in other parts of the world. Attempts are being made to prepare vaccines that can be administered more easily to large populations.