Hepatitis A

Hepatitis A is a common viral infection worldwide that is transmitted via the fecal-oral route. The incidence of infection in the United States decreased by more than 90% after an effective vaccine was introduced, but the number of cases has been increasing because of large community outbreaks in unimmunized individuals. Classic symptoms include fever, malaise, dark urine, and jaundice and are more common in older children and adults. People are most infectious 14 days before and seven days after the development of jaundice. Diagnosis of acute infection requires the use of serologic testing for immunoglobulin M anti-hepatitis A antibodies. The disease is usually self-limited, supportive care is often sufficient for treatment, and chronic infection or chronic liver disease does not occur. Routine hepatitis A immunization is recommended in children 12 to 23 months of age. Immunization is also recommended for individuals at high risk of contracting the infection, such as persons who use illegal drugs, those who travel to areas endemic for hepatitis A, incarcerated populations, and persons at high risk of complications from hepatitis A, such as those with chronic liver disease or HIV infection. The vaccine is usually recommended for pre- and postexposure prophylaxis, but immune globulin can be used in patients who are too young to be vaccinated or if the vaccine is contraindicated.

Hepatitis A vaccine immunogenicity 25 years after vaccination in Alaska

The hepatitis A vaccine is recommended for all children greater than or equal to 1 year of age, however, the duration of vaccine protection is unknown and protection through adulthood is crucial to prevent symptomatic hepatitis later in life. We report on 25 years of follow-up of a cohort of Alaska Native individuals who were vaccinated in early childhood. We assessed the duration of vaccine protection by calculating the geometric mean concentration and proportion of participants with protective levels of IgG antibody to hepatitis A virus (anti-HAV) (≥20 mIU/mL) every 2 to 3 years. We estimated the amount of time until the anti-HAV dropped below protective levels using survival analyses. At 25 years, 43 of the original 144 participants were available, mean anti-HAV levels were 91.5 mIU/mL, and 35 (81.4%) had protective levels of anti-HAV. Using data from all persons and all time points, a survival analysis estimated 78.7% of participants had protective levels of anti-HAV at 25 years. The high level of protective antibodies in this cohort indicate that supplemental doses of hepatitis A vaccine are not needed 25 years after completion of the vaccine series.

The excretion rate and stability of HAAg in human fecal samples after live attenuated hepatitis A vaccination

The live attenuated hepatitis A virus vaccine (HA-L) is in routine use in the Chinese national immunization program (NIP). The major disadvantages of HA-L include that theoretically, it may be possible for mutation shifts and secondary infections of the live vaccine viral strain. The aim of this study was to explore variation in the viral strain after vaccination with the HA-L. A total of 1297 fecal samples (including 470 for the 18 to 36-month-old age group, 527 for the 3 to 16-year-old group, and 300 for the 16 years and older group) were collected in the study, and the rate of hepatitis A virus (HAV) positivity in fecal samples was 11.36% (31/273), 11.44% (31/271), 9.70% (26/268), 8.47% (21/248), and 9.70% (23/237) on days 0, 7, 14, 21 and 28, respectively. A total of 77 HAV positive samples were randomly selected for VP1/2A (360 bp, 2218-2577) gene analysis. Phylogenetic trees were then constructed by the neighbor-joining method. Phylogenetic analyses showed that all the isolated HAV strains belonged to sub-genotype IB, which was the same as the vaccine strain. Compared with the vaccine strain, HM-175/7MK-5 (M16632.1), there were only two base mutations discovered, at 2291 and 2568. However, the amino acid mutation analysis showed that those base mutations were synonymous mutations. The isolated HAV strains were genetically stable. This study provides a reference for the safety concern regarding the routine and wide-range use in people older than 18 months.

Hepatitis A and B Vaccination in the United States

Use of hepatitis A vaccine is a main component of travel vaccination practices. In the United States, fluctuations in the number of annual hepatitis A infections have occurred recently due to large outbreaks related to imported foods and urban transmission among homeless individuals, warranting consideration for wider local use of hepatitis A vaccine. Hepatitis B vaccine is indicated for all adults, and especially healthcare workers. Since 1992, it has been administered at birth. A new novel hepatitis B vaccine given in two doses one month apart is available and has increased efficacy in adults. This article reviews the complete administration of these hepatitis vaccines.

Comparison of the immunogenicity and safety of 3 inactivated hepatitis A vaccines in Korean children aged 12 to 18 months: An open-label, randomized, prospective, multicenter study

Several approved inactivated hepatitis A (HA) vaccines are available in Korea. These have been shown to be immunogenic and safe in European children; however, their immunogenicity and safety have not been investigated among Korean children. We aimed to compare the immunogenicity and safety of the most commonly used HA vaccines in ethnic Korean children aged 12 to 18 months.In this open-label, randomized, prospective, multicenter study, 108 children were enrolled and randomized to receive a pediatric form of Avaxim, Epaxal, or Havrix. The 2nd dose was administered after an interval of 6 months. Anti-HA virus (HAV) immunoglobulin (Ig) G was measured to assess geometric mean concentrations (GMCs) and seropositvity rates (≥20 mIU/mL anti-HAV IgG). To assess safety, local solicited adverse events (AEs), systemic solicited AEs, unsolicited AEs, and serious AEs (SAEs) were graded.Among the 108 participants enrolled, 37, 34, and 37 received Avaxim, Epaxal, and Havrix, respectively. After administration of 2 doses, the seropositivity rates in the Avaxim, Epaxal, and Havrix groups were all 100% (95% confidence intervals [CIs]: 99.0-100, 98.9-100, and 99.0-100, respectively; P < .001). The anti-HAV GMCs in the Avaxim, Epaxal, and Havrix groups were 5868.4 (95% CI: 4237.2-8126.6), 1962.1 (95% CI: 1298.0-2965.9), and 2232.9 mIU/mL (95% CI: 1428.4-3490.4), respectively, after administration of 2 doses (P < .001). There were no significant differences in the proportions of participants reporting local solicited AEs, systemic solicited AEs, unsolicited AEs, and SAEs among the 3 vaccine groups after the 1st and 2nd doses. All local solicited and unsolicited AEs were grade 1 or 2. Grade 3 systemic solicited AE occurred in 5.4% and 2.9% of the participants in the Havrix group after the 1st and 2nd doses, respectively. SAEs after the 1st and 2nd doses were reported in 2 participants and 1 participant, respectively, but none was assessed as being related to vaccination.The results indicate that these vaccines were safe and immunogenic in ethnic Korean children. The results have contributed to the establishing of an HA vaccination policy in Korea and will be informative to countries that plan to initiate vaccination programs against HAV.

Establishment of detection antibodies BRRs batch 5 for in vitro potency assay of hepatitis A vaccines by ELISA

The European Pharmacopoeia (Ph. Eur.) standard ELISA method for determination of antigen content of hepatitis A vaccines (HAV) requires specific coating and detection Biological Reference Reagents (BRRs). The 4th batch of detection antibodies BRRs was established in 2017 for use in conjunction with the Ph. Eur. General Chapter 2.7.14 Assay of hepatitis A vaccine. Stocks of these BRRs were running low and therefore the European Directorate for the Quality of Medicines and HealthCare (EDQM) organised a collaborative study to qualify replacement batches. The candidate BRR antibodies batch 5 were prepared under appropriate conditions from starting materials similar to previous batches to ensure continuity. Prior to the study, a low level of detection was obtained with new batches of the HRPO-GAM provided by the established supplier, supposedly due to a manufacturing issue in the conjugation step. Several other batches procured from the same supplier were tested without any success. Consequently HRPO-GAM batches from 3 other suppliers were tested and one batch was chosen to be included as a BRR based on its suitable characteristics. During the collaborative study, the new batches of antibodies were compared to previous batches of BRRs. Results confirmed that they were suitable to be used for the intended purpose, and could be used at the same final concentrations as the previous batch, i.e. 1:500 for the primary antibody and 1:400 for the conjugated secondary antibody. A higher background OD than in previous batches was observed, so it is recommended to subtract the background from the OD values obtained in the test in order to plot the sigmoid curve and calculate the titre of test samples. Moreover it is recommended that the first dilutions used for the IS and BRP2 should be 1:2 and 1:20, respectively, in order to achieve the same ODmax as for the previous BRRs batches. The BRRs were adopted by correspondence in October 2018 by the Ph. Eur. Commission and are presented as a set containing Hepatitis A virus primary detection antibody BRR batch 5 and Conjugated secondary detection antibody BRR batch 5. They are available from the EDQM as Hepatitis A vaccine ELISA detection antibodies set BRR batch 5.

Establishment of an erythropoietin CRS with stable measurable dimer content for SEC system suitability qualification

The European Pharmacopoeia (Ph. Eur.) monograph 1316 'Erythropoietin concentrated solution' prescribes that the dimer content of therapeutic erythropoietin (EPO) preparations must not exceed 2% as determined by Size-Exclusion Chromatography (SEC). This report describes the evaluation of a candidate Chemical Reference Substance (cCRS) to serve as system suitability reference material for the qualification of SEC systems used to assess dimer and oligomer content in EPO solutions. The study organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) was performed with the participation of six European laboratories which tested the candidate material and the EPO for physicochemical tests CRS batch 1. The candidate material was shown to be a suitable reference material for the determination of the resolving capability of the SEC system for separation of dimer and higher oligomers from monomeric EPO. The cCRS was adopted by the Ph. Eur. Commission as Erythropoietin for SEC system suitability CRS batch 1 following consideration of the report. The importance of the resolving capability of the SEC system, as defined by the peak ratios or the peak-to-valley resolution, together with the asymmetry of the peaks eluted, and the linear response of the UV detector were all seen as critical parameters. Therefore, the monograph Erythropoietin concentrated solution (1316) was revised concomitantly to take account of the CRS and to set acceptance criteria for these critical parameters..

Hepatitis A vaccination coverage among adolescents (13-17 years) in the United States, 2008-2016

BACKGROUND

The hepatitis A (HepA) vaccine was recommended by the Advisory Committee on Immunization Practices (ACIP) incrementally from 1996 to 1999. In 2006, HepA vaccine was recommended (1) universally for children aged 12-23 months, (2) for persons who are at increased risk for infection, or (3) for any person wishing to obtain immunity. Catch-up vaccination can be considered.

OBJECTIVE

To assess HepA vaccine coverage among adolescents and factors independently associated with vaccination administration in the US.

METHODS

The 2008-2016 National Immunization Survey-Teen was utilized to determine 1 and ≥2 dose HepA vaccination coverage among adolescents aged 13-17 years. Factors associated with HepA vaccine series initiation (1 dose) were determined by bivariate and multivariable analyses. Data were stratified by state groups based on ACIP recommendation: universal child vaccination recommended since 1999 (group 1); child vaccination considered since 1999 (group 2); universal child vaccination recommendation since 2006 (group 3).

RESULTS

In 2016, national vaccination coverage for 1 and ≥2 doses of HepA vaccine among adolescents was 73.9% and 64.4%, respectively. Nationally, a 40 percentage point increase in vaccination coverage occurred among adolescents born in 1995 compared to adolescents born in 2003. Nationally, the independent factors associated with increased vaccine initiation was race/ethnicity (Hispanic, American Indian/Alaskan Native, Asian), military payment source and provider recommendation for HepA vaccination (2008-2013). Living in a suburban or rural region, living in poverty (level <1.33-5.03), and absence of state daycare or school HepA requirement were common factors associated with decreased likelihood of vaccine initiation.

CONCLUSIONS

Efforts to increase HepA vaccine coverage in adolescents in all regions of the country would strengthen population protection from hepatitis A virus (HAV).

A case of acute hepatitis A infection in an HIV-positive patient despite complete hepatitis A vaccination

BACKGROUND

Vaccination against hepatitis A virus infection is recommended for men who have sex with men and other risk groups. The protection offered by the combined hepatitis A and B vaccine is comparable to that offered by the monovalent hepatitis A vaccine.

CASE

A 38-year-old HIV-positive patient presented with right upper abdominal pain, fever and jaundice. Serological work-up and detection of hepatitis A RNA in stool sample revealed an acute hepatitis A infection despite a previous complete vaccination with the combined hepatitis A and B vaccine.

CONCLUSION

Although the combined hepatitis A and B vaccine is associated with very good seroconversion rates, the effectiveness in HIV-positive patients is not ensured, even in cases with CD4 cell counts of > 500/μl. Therefore, regular post-vaccine testing should be encouraged to assess seroconversion in immunocompromised subjects.

Establishment of detection antibodies BRRs batch 4 for in vitro potency assay of hepatitis A vaccines by ELISA

The European Pharmacopoeia (Ph. Eur.) standard ELISA method for determination of antigen content of hepatitis A vaccines (HAV) requires specific coating and detection Biological Reference Reagents (BRRs). The 3^rd batch of detection antibodies BRRs was established in 2015 for use in conjunction with the Ph. Eur. general chapter 2.7.14 'Assay of hepatitis A vaccine'. Stocks of these BRRs were running low and therefore the European Directorate for the Quality of Medicines & HealthCare (EDQM) organised a collaborative study to qualify replacement batches. The candidate BRR antibodies batch 4 were prepared under appropriate conditions from starting materials similar to previous batches to ensure continuity. During the collaborative study, the new batches of antibodies were compared to previous batches of BRRs. Results confirmed that they were suitable to be used for the intended purpose, and could be used at the same final concentrations as the previous batch, i.e. 1:500 for the primary antibody and 1:400 for the conjugated secondary antibody. They were adopted in June 2017 by the Ph. Eur. Commission as Hepatitis A virus primary detection antibody BRR batch 4 and Conjugated secondary detection antibody BRR batch 4, respectively. They are available from the EDQM as Hepatitis A vaccine ELISA detection antibodies set BRR batch 4.

Immunogenicity and safety of the inactivated hepatitis A vaccine in children with juvenile idiopathic arthritis on methotrexate treatment: a matched case-control study

OBJECTIVES

To describe the immunogenicity and side effects of immunisation against hepatitis A virus (HAV) in JIA patients on methotrexate treatment, who have not been previously exposed to HAV.

METHODS

Case-control study performed in JIA patients and healthy controls matched on age and gender. The subjects received two doses of inactivated anti-HAV vaccine (720 mIU/ml) intramuscularly at 0 and 6 months. Seroconversion, seroprotection rates and anti-HAV-IgG titres were measured at 1, 7 and 18 months. Children were monitored for adverse events.

RESULTS

83 JIA patients and 76 controls were enrolled in the study. At one month, seroprotection rates were lower in children with, as compared to those without JIA (48.2% vs. 65%; p=0.05). At 7 and 18 months, rates of seroprotection rose significantly and were similar in both groups. The titre of anti-HAV-IgG was lower in children with JIA than healthy children at all time points (p<0.001). Vaccines were well tolerated.

CONCLUSIONS

Two doses of inactivated HAV vaccine were well tolerated and immunogenic in most immunosuppressed children with JIA; however, a single dose of HAV vaccine was insufficient to induce seroprotection in half of the patients. Further studies are required to analyse the long-term immunity against HAV in this population and optimal HAV immunisation regimen.

Comparison of immune persistence among inactivated and live attenuated hepatitis a vaccines 2 years after a single dose

OBJECTIVE

Compare immune persistence from one dose of each of 3 different hepatitis A vaccines when given to school-age children: a domestic, live attenuated hepatitis A vaccine (H2 vaccine); a domestic inactivated hepatitis A vaccine (Healive®); and an imported, inactivated hepatitis A vaccine (Havrix®),.

METHODS

School-age children were randomized into 1 of 4 groups to receive a single dose of a vaccine: H2 vaccine, Healive®, Havrix®, or hepatitis B vaccine [control]. Serum samples were collected 12 and 24 months after vaccination for measurement of anti-HAV IgG using microparticle enzyme immunoassay. Seropositivity was defined as ≥ 20 mUI/ml. We compared groups on seropositivity and geometric mean concentration (GMC).

RESULTS

Seropositive rates for the H2, Healive®, Havrix®, and control groups were 64%, 94.4%, 73%, and 1.0%, respectively, 12-months post-vaccination; and 63%, 95.6%, 72%, and 1.0%, respectively 24-months post-vaccination. Seropositivity was greater for Healive® than for H2 and Havrix® at 12 months (p-values < 0.001) and 24 months (p-values < 0.0001). Average GMCs for the H2, Healive®, Havrix®, and control groups, in mIU/ml, were 29.7, 81.0, 36.4, and 2.9, respectively at 12 months, and 30.9, 112.2, 44.3, and 2.9, respectively, at 24 months. GMCs were greater for Healive® than for H2 and Havrix® at 12 months (p-values < 0.0001 and < 0.001, respectively) and 24 months (p-values < 0.001). No statistically significant differences in seropositivity or GMC were found within groups between 12 and 24 months.

CONCLUSION

Immunity persisted 24 months after a single dose of inactivated hepatitis A vaccine and live attenuated hepatitis A vaccine.

Changing Epidemiological Characteristics of Hepatitis A in Zhejiang Province, China: Increased Susceptibility in Adults

Background

Hepatitis A is a common acute hepatitis caused by hepatitis A virus (HAV). Annually, it affects 1.4 million people worldwide. Between 1991 and 1994, HAV infections were highly endemic in Zhejiang Province (China), with 78,720 reported HAV infections per year. Hepatitis A vaccine came on the market in 1995 and was implemented for voluntary immunization. Since 2008, hepatitis A vaccine has been integrated into the national childhood routine immunization program.

Objective

To understand the current epidemiological profile of hepatitis A in Zhejiang Province since hepatitis A vaccine has been available for nearly two decades.

Methods

This study used the 2005–2014 National Notifiable Diseases Reporting System data to evaluate the incidence rate of notified hepatitis A cases in Zhejiang Province.

Results

The overall trend of incidence rate of notified hepatitis A cases significantly decreased from 2005 to 2014 (P< 0.001). During the study period, the reported incidence rate in individuals aged ≤19 years declined to the historically lowest record in 2014. Compared with individuals aged ≤19 years, those aged ≥20 years showed the highest incidence rate (P< 0.001). Majority of HAV infected cases were Laborers, accounting for approximately 70% of reported cases.

Conclusions

Childhood immunization strategy with hepatitis A vaccine seemed to be effective in decreasing notified hepatitis A incidence rate in individuals aged ≤19 years. Those aged ≥20 years were observed to be the most susceptible population. The vast majority of hepatitis A cases were notified among Laborers. Therefore, we strongly suggest that future preventive and control measures should focus more on adults, particularly Laborers, in addition to the current childhood hepatitis A vaccination programme.

Reappraisal of the Immunogenicity and Safety of Three Hepatitis A Vaccines in Adolescents

Although the overall incidence of hepatitis A in Korea has been decreasing, adolescents remain highly vulnerable to its outbreaks. This study was conducted to compare the immunogenicity and safety of three hepatitis A vaccines in Korean adolescents. Healthy anti-hepatitis A virus seronegative subjects aged 13 to 19 yr were randomized in three equal groups to receive two doses of Avaxim™, Epaxal®, or Havrix®, 6 to 12 months apart. Seroconversion rates one month after the first dose were 98%, 95%, and 93% for Avaxim™, Epaxal®, and Havrix®, respectively. Seroconversion rates reached 100% for all vaccine groups one month after the second dose. Anti-HAV geometric mean concentrations (GMCs) were 7,207.7 mIU/mL (95% CI, 6023.1-8684.7), 1,750.5 mIU/mL (95% CI, 1362.9-2248.3), and 1,953.5 mIU/mL (95% CI, 1459.4-2614.7) after two doses of Avaxim™, Epaxal®, and Havrix® respectively. Avaxim™ was significantly more immunogenic than Epaxal® and Havrix®, whereas there were no significant differences in antibody responses between Epaxal® and Havrix®. Local and systemic solicited adverse events (AEs) were mostly of mild-to-moderate intensity and resolved within 5 days. No serious AEs were reported. In conclusion, all three vaccines are highly immunogenic and well-tolerated in Korean adolescents. (Clinical Trial Registry NCT00483470).

[The incidence of viral hepatitis A in the Hradec Králové Region in the Czech Republic in the last decade]

OBJECTIVE

Viral hepatitis A continues to occur in the Czech Republic due to the high susceptibility of the population and existing opportunities for the transmission of the disease. The aim was to describe and analyse the incidence of viral hepatitis A in the Hradec Králové Region in the Czech Republic in 2005-2014, including the study of two outbreaks that required a different approach of field epidemiologists.

MATERIAL AND METHODS

In 2015, a retrospective analysis was carried out of the data on the incidence of viral hepatitis A in Hradec Králové Region in 2005-2014. The EPIDAT system where cases of infectious diseases and data from epidemiological investigations are reported was used as a data source for the purposes of the present analysis. In addition, two final reports on epidemic outbreaks of viral hepatitis A from 2014 were assessed.

RESULTS

The incidence of viral hepatitis A at the regional level follows, to a certain extent, the pattern of the incidence of this disease at the national level. The highest number of cases was reported in 2010 due to a country-wide epidemic. The most affected age groups were children, adolescents, and young adults. The incidence of viral hepatitis A in individual years has a significant effect on the emergence of local outbreaks.

CONCLUSION

The incidence of viral hepatitis A in the Czech Republic has a fluctuating trend, at both the national and regional levels. The highest incidence of viral hepatitis A was observed in the younger and middle-age categories. The high susceptibility of these population groups suggests the importance of vaccination against viral hepatitis A that confers specific personal protection.Key words: viral hepatitis A - incidence - outbreak - Czech Republic.

Seropositivity among Korean Young Adults Approximately 2 Years after a Single-Dose Vaccination against Hepatitis A Virus

We previously observed 80.7% seropositivity and a significant interaction between gender and hepatitis A virus (HAV) vaccine type (Havrix vs. Epaxal) on the seropositivity approximately 11 months after single-dose HAV vaccinations in Korean young adults. Our objective was to evaluate seropositivity approximately 2 years after a single-dose HAV vaccination and the influence of demographic characteristics on seropositivity, including the interaction between gender and vaccine type. Seronegative medical school students were randomly vaccinated with Havrix or Epaxal. Based on a total serum anti-HAV antibody titer cutoff of 20 IU/mL, 338 participants (76.0%) of the 445 vaccinees were seropositive 20–25 months after a single-dose HAV vaccination. The seropositive rates were similar after vaccination with Havrix (77.0%) and Epaxal (74.9%). Univariate analysis indicated that female (p = 0.052) and less obese (p < 0.001) participants had a higher seropositive rate, whereas other characteristics such as age, alcohol use, smoking history, vaccine type, and follow-up duration were not associated with seropositivity. Multivariate analysis indicated that women (p = 0.026) and participants with moderate alcohol use (p < 0.001) showed significantly higher seropositive rates than men and participants with no or low alcohol use, respectively. The seropositive rates after vaccination with Havrix and Epaxal were 70.9% and 67.5% in men and 87.7% and 91.3% in women, respectively (p for interaction = 0.304). Compared with the seropositive rate approximately 11 months after vaccination, the seropositive rate decreased substantially only in men in the Havrix group (11.0% points), and consequently, the interaction between gender and vaccine type disappeared while seropositivity remained high (87.7% and 91.3% in Havrix and Epaxal groups, respectively) among women approximately 2 years after vaccination. Further studies are needed to assess whether the seropositive rate would be maintained in all groups more than 2 years after a single-dose HAV vaccination.

Self-reported hepatitis A vaccination as a predictor of hepatitis A virus antibody protection in U.S. adults: National Health and Nutrition Examination Survey 2007-2012

OBJECTIVES

To estimate the predictive value of self-reported hepatitis A vaccine (HepA) receipt for the presence of hepatitis A virus (HAV) antibody (anti-HAV) from either past infection or vaccination, as an indicator of HAV protection.

METHODS

Using 2007-2012 National Health and Nutrition Examination Survey data, we assigned participants to 4 groups based on self-reported HepA receipt and anti-HAV results. We compared characteristics across groups and calculated three measures of agreement between self-report and serologic status (anti-HAV): percentage concordance, and positive (PPV) and negative (NPV) predictive values. Using logistic regression we investigated factors associated with agreement between self-reported vaccination status and serological results.

RESULTS

Demographic and other characteristics varied significantly across the 4 groups. Overall agreement between self-reported HepA receipt and serological results was 63.6% (95% confidence interval [CI] 61.9-65.2); PPV and NPV of self-reported vaccination status for serological result were 47.0% (95% CI 44.2-49.8) and 69.4% (95% CI 67.0-71.8), respectively. Mexican American and foreign-born adults had the highest PPVs (71.5% [95% CI 65.9-76.5], and 75.8% [95% CI 71.4-79.7]) and the lowest NPVs (21.8% [95% CI 18.5-25.4], and 20.0% [95% CI 17.2-23.1]), respectively. Young (ages 20-29 years), US-born, and non-Hispanic White adults had the lowest PPVs (37.9% [95% CI 34.5-41.5], 39.1% [95% CI, 36.0-42.3], and 39.8% [36.1-43.7]), and the highest NPVs (76.9% [95% CI 72.2-81.0, 78.5% [95% CI 76.5-80.4)], and 80.6% [95% CI 78.2-82.8), respectively. Multivariate logistic analyses found age, race/ethnicity, education, place of birth and income to be significantly associated with agreement between self-reported vaccination status and serological results.

CONCLUSIONS

When assessing hepatitis A protection, self-report of not having received HepA was most likely to identify persons at risk for hepatitis A infection (no anti-HAV) among young, US-born and non-Hispanic White adults, and self-report of HepA receipt was least likely to be reliable among adults with the same characteristics.

Vaccination policy in Korean armed forces: current status and future challenge

Infectious diseases have historically resulted in suspended or cancelled military operations. Vaccination for disease prevention is a critical component of the military's force readiness doctrine. Until recently, Korea had not recognized the importance of vaccinating military personnel. However, a 2011 meningococcal disease outbreak at an army recruit training center led to dramatic changes in the paradigm of traditional medical practice in the Korean armed forces. A new vaccination policy was formed by a 2012 Military Healthcare Service Act. Since then, Neisseria meningitidis, hepatitis A, and measles-mumps-rubella vaccines have been routinely administered to all new recruits early in basic training to ensure protection against these diseases. All active-duty soldiers also receive seasonal influenza vaccination annually. Despite quantitative improvements in vaccination policies, several instances of major infectious diseases and adverse vaccine reactions have threatened soldier health. In the future, vaccination policies in the Korean armed forces should be based on epidemiologic data and military medical research for vaccine use and safety management.

Long term follow-up study to evaluate immunogenicity and safety of a single dose of live attenuated hepatitis a vaccine in children

Worldwide, viral hepatitis continues to be a cause of considerable morbidity and mortality. Mass immunization with a single dose of live attenuated HAV has been shown to significantly reduce disease burden in the community. This was a phase IV, 5-year follow up study carried out at 4 centers (Kolkata, Delhi, Mumbai and Chennai) across India. The subjects with antibody titer <20 mIU/mL at baseline were evaluated for long term immunogenicity. Of the 503 subjects enrolled, 349 subjects were baseline seronegative with an anti-HAV antibody titer <20 mIU/mL. Overall, 343 subjects could be followed up at some point of time during this 5 y post vaccination period. In the last year (60 months) of follow-up, 108 subjects (97.3%) of 111 subjects (who came for follow-up at the end of 5 y) had a protective antibody titer (anti-HAV antibody titer >20 mIU/mL). The seroconversion rates considering seroprotection levels of anti-HAV antibody titer >20 mIU/mL, following vaccination starting from 6 weeks, 6 months, 12 months, 24 months, 36 months, 48 months and 60 months were 95.1%, 97.9%, 98.3%, 96.2%, 97.8%, 92.6% and 97.3%, respectively. The geometric mean concentration (GMC) over the years increased from 64.9 mIU/mL at 6 weeks to 38.1 mIU/mL and 135.2 mIU/mL at 6 months and 12 months, respectively and was maintained at 127.1 mIU/mL at 60 months. In conclusion, the result of this 5-year follow up study showed that the single dose of live attenuated vaccine is well tolerated and provides long-term immunogenicity in healthy Indian children.

Public acceptance and willingness to hepatitis a vaccination in children aged 7-18 years in Republic of Korea

Hepatitis A can cause serious illness among adolescents and adults with low vaccination coverage. Even though hepatitis A vaccine is one of the strong candidates for Korean national immunization program, adolescents aged older than 12 yr would not benefit. Our purpose was to assess the willingness and analyze the correlates of Korean mothers for hepatitis A (HepA) vaccination to develop strategies for HepA vaccination. A national telephone survey on 800 mothers with children aged 7-18 yr was conducted with random-digit dialing method. Sixty-two percent and 92% of the mothers reported that they were willing to HepA vaccination at current cost and at half of the current cost, respectively. However, at current cost, only 79% wished to vaccinate their child in an epidemic and 32% wished to vaccinate promptly. Having two or more children, not having future plans to send the child overseas, and low family income were significantly associated with not willing to HepA vaccination. Low perception of the susceptibility for hepatitis A and perception of the current cost as barrier increased the odds of unwillingness to vaccination at current cost and to prompt vaccination. The mothers' willingness to HepA vaccination for the children aged 7-18 yr in Korea was not very high at current cost and associated socioeconomic status and health-belief. Targeted intervention or strategies are needed to increase the HepA vaccination rate among children in Korea.

The duration of hepatitis B vaccine immunity in pediatric dialysis patients

BACKGROUND

Dialysis patients are at risk for hepatitis B infection, a serious but preventable disease. Long-term hepatitis B protection has not been defined in pediatric patients with chronic kidney disease stage 5 on dialysis (CKD 5D) who were vaccinated as infants or children.

METHODS

Annual hepatitis B antibody surveillance data were collected retrospectively on a cohort of pediatric CKD 5D patients (n = 202) at a single institution and analyzed by survival analysis to assess hepatitis B immunity duration.

RESULTS

Median duration of immunity by Kaplan-Meier analysis since primary vaccination was 106.3 [95 % confidence interval (CI) 93.9, 124.4] months. After the initiation of dialysis, the median duration of hepatitis B immunity was 37.1 (95 % CI 24.2, 72.3) months. Multivariate adjusted analysis showed that there was a significant difference in the duration of hepatitis immunity based on the timing of hepatitis B vaccination (p < 0.001). Patients immunized after starting dialysis had a hazard ratio of 6.13 (95 % CI 2.87, 13.08) for hepatitis B immunity loss compared to patients immunized as infants (p < 0.001).

CONCLUSIONS

After dialysis initiation, protective hepatitis B antibody levels wane rapidly, with a shortened duration of immunity. In our cohort of pediatric patients with CKD 5D, this decline was more pronounced in children who were immunized after starting dialysis than in those who received hepatitis B immunizations during childhood. Both groups of patients should be monitored with serial antibody titers.

Hepatitis A vaccine for immunosuppressed patients with rheumatoid arthritis: a prospective, open-label, multi-centre study

BACKGROUND

Hepatitis A vaccine is the most frequently used travel vaccine, yet data are scarce about its ability to induce protection in patients with concurrent immunosuppressive treatment. We assessed the immunogenicity of this vaccine in rheumatoid arthritis (RA) patients treated with tumour necrosis factor-inhibitors (TNFi) and/or methotrexate (MTX).

METHODS

Hepatitis A vaccine was administered to non-immune RA patients at 0 and 6 months. Hepatitis A virus (HAV) antibodies were assessed at 0, 1, 6, 7, 12, and 24 months with a quantitative Chemiluminescent Microparticle Immuno Assay (CMIA) for HAV-IgG. Samples from month 1, 6, and 7 were, in addition, analysed with a microparticle EIA (MEIA) for anti-HAV IgM + IgG.

RESULTS

The final study population consisted of 53 patients treated with TNFi (n = 15), TNFi + MTX (n = 21) or MTX (n = 17). One and six months after the first dose, 10% and 33% of the patients had attained seroprotection. One and six months after the second dose 83% and 72% were seroprotected. At month 24, 86% of the vaccinees showed protective levels.

CONCLUSIONS

Two doses of hepatitis A vaccine at a 6-month interval provided protection for most immunosuppressed RA patients. A single dose does not seem to afford sufficient protection to this group of patients.

Hepatitis A and considerations regarding the cost-effectiveness of vaccination programs

Hepatitis A vaccines have demonstrated a high degree of immunogenicity and an excellent safety profile. Immunization of certain populations and patient subgroups is recommended according to specific epidemiological and clinical factors, such as a greater likelihood of acquisition of infection or concerns regarding the risk of development of fulminant hepatitis and death. Therefore, the economic implications of routine and/or targeted vaccination programs in the general population and high-risk individuals have been examined. In this manuscript, the available data from the literature regarding the cost-effectiveness of hepatitis vaccination programs in healthy individuals and in those with chronic liver disease are reviewed.

Live attenuated hepatitis A vaccines developed in China

Two live, attenuated hepatitis A vaccines, H 2 and LA-1 virus strains, were developed through serial passages of the viruses in cell cultures at 32 °C and 35 °C respectively. Both vaccines were safe and immunogenic, providing protection against clinical hepatitis A in 95% of the vaccinees, with a single dose by subcutaneous injection. The vaccine recipients were not protected from asymptomatic, subclinical hepatitis A virus (HAV) infection, which induced a similar antibody response as for unvaccinated subjects. A second dose caused anamnestic response and can be used for boosting. Oral immunization of human with H 2 vaccine or of marmoset with LA-1 vaccine failed, and no evidence was found for person-to-person transmission of the H 2 strain or for marmoset-to-marmoset transmission of LA-1 strain, by close contact. H 2 strain was genetically stable when passaged in marmosets, humans or cell cultures at 37 °C; 3 consecutive passages of the virus in marmosets did not cause virulence mutation. The live vaccines offer the benefits of low cost, single dose injection, long- term protection, and increased duration of immunity through subclinical infection. Improved sanitation and administration of 150 million doses of the live vaccines to children had led to a 90% reduction in the annual national incidence rate of hepatitis A in China during the 16-year period, from 1991 to 2006. Hepatitis A immunization with both live and inactivated HA vaccines was implemented in the national routine childhood immunization program in 2008 and around 92% of the 16 million annual births received the affordable live, attenuated vaccines at 18 months of age. Near elimination of the disease was achieved in China for 14 years following introduction of the H 2 live vaccine into the Expanded Immunization Program (EPI) in 1992.

[Evaluation on the effect of immunization and safety of live attenuated and inactivated hepatitis A vaccine in China]

OBJECTIVE

To evaluate the safety of both domestic live attenuated and inactivated hepatitis A vaccines, and to provide reference for emergent vaccination after hepatitis A outbreaks.

METHODS

493 children aged 6 - 9 with negative antibody to HAV (produced by Abbott) were randomly divided into four groups as vaccinated with domestic live attenuated hepatitis A vaccine (Group A), domestic inactivated hepatitis A vaccine (Group B), imported inactivated hepatitis A vaccine (Group C) and hepatitis B vaccine (Group D) respectively. Adverse events following the immunization were observed 30 minutes, 24, 48 and 72 hours after the vaccination, under double-blind method.

RESULTS

The main AEFIs were: fever, local pain and scleroma but no other severe AEFIs were observed. The rates of AEFIs were 13.95% in Group A, 15.25% in group B, 16.80% in group C and 25.62% in group D, with no statistical differences between these groups (χ(2) = 6.953, P > 0.05). 2 weeks after the vaccination, the positive conversion rates of domestic live attenuated hepatitis A vaccine and domestic inactivated hepatitis A vaccine were 85.0% and 94.59% respectively. The rate of domestic inactivated hepatitis A vaccine reached 100% at 4 weeks after the vaccination. The antibody levels of HAV-IgG of Group A and B in 2, 4 and 12 weeks of vaccination and of Group C were higher than that of Group D. After 12 weeks of vaccination, the antibody level of group B became higher than it was Group C.

CONCLUSION

There were no differences on safety among domestic live attenuated hepatitis A vaccine, domestic inactivated hepatitis A vaccine or imported inactivated hepatitis A vaccine under routine or emergency vaccination. All the vaccines showed satisfactory effects.

Validation of a new ELISA method for in vitro potency testing of hepatitis A vaccines

The goal of the project was to standardise a new in vitro method in replacement of the existing standard method for the determination of hepatitis A virus antigen content in hepatitis A vaccines (HAV) marketed in Europe. This became necessary due to issues with the method used previously, requiring the use of commercial test kits. The selected candidate method, not based on commercial kits, had already been used for many years by an Official Medicines Control Laboratory (OMCL) for routine testing and batch release of HAV. After a pre-qualification phase (Phase 1) that showed the suitability of the commercially available critical ELISA reagents for the determination of antigen content in marketed HAV present on the European market, an international collaborative study (Phase 2) was carried out in order to fully validate the method. Eleven laboratories took part in the collaborative study. They performed assays with the candidate standard method and, in parallel, for comparison purposes, with their own in-house validated methods where these were available. The study demonstrated that the new assay provides a more reliable and reproducible method when compared to the existing standard method. A good correlation of the candidate standard method with the in vivo immunogenicity assay in mice was shown previously for both potent and sub-potent (stressed) vaccines. Thus, the new standard method validated during the collaborative study may be implemented readily by manufacturers and OMCLs for routine batch release but also for in-process control or consistency testing. The new method was approved in October 2012 by Group of Experts 15 of the European Pharmacopoeia (Ph. Eur.) as the standard method for in vitro potency testing of HAV. The relevant texts will be revised accordingly. Critical reagents such as coating reagent and detection antibodies have been adopted by the Ph. Eur. Commission and are available from the EDQM as Ph. Eur. Biological Reference Reagents (BRRs).

Review of 10 years of marketing experience with Chinese domestic inactivated hepatitis A vaccine Healive®

In 2002, the first Chinese domestic preservative-free inactivated hepatitis A vaccine, Healive®, was introduced in China. It is highly immunogenic, and provides lasting protection in healthy individuals and generates protective levels of antibodies in other at-risk individuals. Over 10 years since its first licensure, postmarketing surveillance data have confirmed the outstanding safety profile of the vaccine. Comparative clinical trials indicated that Healive® induce equal or similar immunogenicity with other currently available inactivated hepatitis A vaccines and are interchangeable for the course of HAV immunization in Chinese children. The vaccine is effective in curbing outbreaks of hepatitis A due to rapid seroconversion and the long incubation period of the disease. Additional issues surrounding the use of the vaccine are also reviewed.

Hepatitis A immunisation in persons not previously exposed to hepatitis A

BACKGROUND

In many parts of the world, hepatitis A infection represents a significant cause of morbidity and socio-economic loss. Whilst hepatitis A vaccines have the potential to prevent disease, the degree of protection afforded against clinical outcomes and within different populations remains uncertain. There are two types of hepatitis A virus (HAV) vaccine, inactivated and live attenuated. It is important to determine the efficacy and safety for both vaccine types.

OBJECTIVES

To determine the clinical protective efficacy, sero-protective efficacy, and safety and harms of hepatitis A vaccination in persons not previously exposed to hepatitis A.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and China National Knowledge Infrastructure (CNKI) up to November 2011.

SELECTION CRITERIA

Randomised clinical trials comparing HAV vaccine with placebo, no intervention, or appropriate control vaccines in participants of all ages.

DATA COLLECTION AND ANALYSIS

Data extraction and risk of bias assessment were undertaken by two authors and verified by a third author. Where required, authors contacted investigators to obtain missing data. The primary outcome was the occurrence of clinically apparent hepatitis A (infectious hepatitis). The secondary outcomes were lack of sero-protective anti-HAV immunoglobulin G (IgG), and number and types of adverse events. Results were presented as relative risks (RR) with 95% confidence intervals (CI). Dichotomous outcomes were reported as risk ratio (RR) with 95% confidence interval (CI), using intention-to-treat analysis. We conducted assessment of risk of bias to evaluate the risk of systematic errors (bias) and trial sequential analyses to estimate the risk of random errors (the play of chance).

MAIN RESULTS

We included a total of 11 clinical studies, of which only three were considered to have low risk of bias; two were quasi-randomised studies in which we only addressed harms. Nine randomised trials with 732,380 participants addressed the primary outcome of clinically confirmed hepatitis A. Of these, four trials assessed the inactivated hepatitis A vaccine (41,690 participants) and five trials assessed the live attenuated hepatitis A vaccine (690,690 participants). In the three randomised trials with low risk of bias (all assessing inactivated vaccine), clinically apparent hepatitis A occurred in 9/20,684 (0.04%) versus 92/20,746 (0.44%) participants in the HAV vaccine and control groups respectively (RR 0.09, 95% CI 0.03 to 0.30). In all nine randomised trials, clinically apparent hepatitis A occurred in 31/375,726 (0.01%) versus 505/356,654 (0.18%) participants in the HAV vaccine and control groups respectively (RR 0.09, 95% CI 0.05 to 0.17). These results were supported by trial sequential analyses. Subgroup analyses confirmed the clinical effectiveness of both inactivated hepatitis A vaccines (RR 0.09, 95% CI 0.03 to 0.30) and live attenuated hepatitis A vaccines (RR 0.07, 95% CI 0.03 to 0.17) on clinically confirmed hepatitis A. Inactivated hepatitis A vaccines had a significant effect on reducing the lack of sero-protection (less than 20 mIU/L) (RR 0.01, 95% CI 0.00 to 0.03). No trial reported on a sero-protective threshold less than 10 mIU/L. The risk of both non-serious local and systemic adverse events was comparable to placebo for the inactivated HAV vaccines. There were insufficient data to draw conclusions on adverse events for the live attenuated HAV vaccine.

AUTHORS' CONCLUSIONS

Hepatitis A vaccines are effective for pre-exposure prophylaxis of hepatitis A in susceptible individuals. This review demonstrated significant protection for at least two years with the inactivated HAV vaccine and at least five years with the live attenuated HAV vaccine. There was evidence to support the safety of the inactivated hepatitis A vaccine. More high quality evidence is required to determine the safety of live attenuated vaccines.

[The characterization analysis of HAV recombinant antigen was expressed by vaccinia virus vector]

OBJECTIVE

To find a suitable cell line for hepatitis A antigen expressed by vaccinia virus vector and to find a way of inactivation and preservation of the HAV recombinant antigen. Methods Series of cell lines such as K4,143, HEL, Hep-2 and Vero were inoculated with vaccinia virus that can express HAV recombinant antigen. ELISA was used to determine the contents of expression antigen. The characterization of the HAV antigen expressed by vaccinia virus was then analyzed after it was treated with different methods.

RESULTS

The expression of HAV recombinant antigen in K4,143 and HEL cell lines was a little more than expression in Hep-2 and Vero cell lines. The antigenicity is obviously higher when HAV recombinant antigen was inactivated by beta-propiolactone other than it was inactivated by formalin. It was best to preserve the prepared HAV recombinant antigen under -40 degrees C condition.

CONCLUSIONS

The application of vaccinia virus vector in hepatitis A antigen preparation was very useful and promising.

Long-term durability of immune responses after hepatitis A vaccination among HIV-infected adults

BACKGROUND

Vaccination provides long-term immunity to hepatitis A virus (HAV) among the general population, but there are no such data regarding vaccine durability among human immunodeficiency virus (HIV)-infected adults.

METHODS

We retrospectively studied HIV-infected adults who had received 2 doses of HAV vaccine. We analyzed blood specimens taken at 1 year, 3 years, and, when available, 6-10 years postvaccination. HAV immunoglobulin G (IgG) values of ≥10 mIU/mL were considered seropositive.

RESULTS

We evaluated specimens from 130 HIV-infected adults with a median age of 35 years and a median CD4 cell count of 461 cells/mm(3) at or before time of vaccination. Of these, 49% had an HIV RNA load <1000 copies/mL. Initial vaccine responses were achieved in 89% of HIV-infected adults (95% confidence interval [CI], 83%-94%), compared with 100% (95% CI, 99%-100%) of historical HIV-uninfected adults. Among initial HIV-infected responders with available specimens, 90% (104 of 116; 95% CI, 83%-95%) remained seropositive at 3 years and 85% (63 of 74; 95% CI, 75%-92%) at 6-10 years. Geometric mean concentrations (GMCs) among HIV-infected adults were 154, 111, and 64 mIU/mL at 1, 3, and 6-10 years, respectively, compared with 1734, 687, and 684 mIU/mL among HIV-uninfected persons. Higher GMCs over time among HIV-infected adults were associated with lower log(10) HIV RNA levels (β = -.12, P = .04).

CONCLUSIONS

Most adults with well-controlled HIV infections had durable seropositive responses up to 6-10 years after HAV vaccination. Suppressed HIV RNA levels are associated with durable HAV responses.

Evaluation of immune response to hepatitis A vaccination and vaccine safety in juvenile idiopathic arthritis

BACKGROUND

Autoimmune mechanisms and drugs used in treatment increase the risk of liver disease in patients with juvenile idiopathic arthritis (JIA) and hepatitis A virus (HAV) vaccination is important, especially in intermediate-endemicity areas like Turkey. In our study, we aimed to evaluate the immune response to hepatitis A vaccine and vaccine safety in children with JIA.

METHODS

This study was carried out in our hospital's Pediatric Rheumatology outpatient clinic and Healthy Child clinic between the years 2003 and 2008. The study group consisted of 47 children with JIA (23 male and 24 female) diagnosed according to International League of Associations for Rheumatology diagnostic criteria. The control group consisted of 67 healthy children (31 female, 36 male) who did not have a history of hepatitis A infection or vaccination. Both groups were vaccinated with two doses of hepatitis A vaccine at 6-month intervals. Anti-HAV IgG >80 MIU was accepted as positive response.

RESULTS

There was no significant difference between the groups in terms of age and sex. None of the patients with JIA had fever, clinical worsening, or disease activation after vaccination. Anti-HAV IgG positivity rate was significantly higher in the control group (p < 0.05). Anti-HAV IgG was negative in only four cases, and they were all male patients with systemic JIA who had active disease under anti-tumor necrosis factor treatment.

CONCLUSION

Hepatitis A vaccine was safe in patients with JIA, and response to vaccine did not differ between healthy children and patients with JIA except for children with active systemic JIA receiving anti-tumor necrosis factor alpha drugs.

Successful memory response following a booster dose with a virosome-formulated hepatitis a vaccine delayed up to 11 years

Boosting adult travelers with the virosome-formulated, aluminum-free hepatitis A vaccine Epaxal up to 128 months after a single primary dose confers full protection against hepatitis A, even in travelers aged 50 years and above. Delaying the booster dose did not influence the immune memory response to Epaxal.

Predictors of hepatitis A vaccination among young children in the United States

We analysed data from the 2009 National Immunization Survey to determine potential predictors of hepatitis A vaccination coverage among children aged 19-35 months. Overall national coverage was 75% for ≥1 dose. Residence in a state with hepatitis A vaccination recommendations prior to 2006, or in a metropolitan statistical area within such state, or being a minority child were among the variables independently associated with higher vaccination coverage. While hepatitis A vaccination coverage has improved since nationwide routine childhood vaccination began in 2006, coverage remains lower than that for other recommended childhood vaccines.

[Long-term immunogenicity and effectiveness of live attenuated hepatitis A vaccine (H2-strain)-a study on the result of 15 years' follow up]

OBJECTIVE

To evaluate the long-term immunogenicity and effectiveness of live attenuated hepatitis A (HA) vaccine (H2 strain) after one dose injection, through a 15 years' follow up observation.

METHODS

A total of 220 children with negative anti-HAV antibody (aged 1-3 y) were involved and followed up in Jiaojiang district, Taizhou city, Zhejiang province. Indicators would include seroconversion and geometric mean titer (GMT) levels after inoculation the vaccine with single dose at 2 m, 12 m, 6 years, 10 years and 15 years. Epidemiological observation was carried out within the 15 years to evaluate the relationship between vaccine coverage, the incidence of HA and the overall effectiveness. In the studied population, serum was tested by ELISA (calibrated by WHO international reference) and ABBOTT Axsym HAVAB mEIA.

RESULTS

Seroconversion rates were found to be 98.6% and 81.3% after 2 months and 15 years of inoculation and slowly decreased. GMT level was 128 mIU/ml after 15 years, significantly higher than the required protective level of 20 mIU/ml, recommended by WHO experts. Effectiveness through the 15-year follow up program showed a significant correlation between vaccine coverage and incidence of HA in 1-15 years aged group (Kendall-Rank test, τ =-0.931, P<0.01). There was no HA case seen among the observed accumulated 236 413 person-year vaccines, compared to 4 HA cases discovered in the 27 206 person-year of the non-vaccinees. The overall protective rate reached 100%. Through a mass vaccination program on children, the whole population established an immune-defence to enable the incidence of HA decreased by 96.7%.

CONCLUSION

The long-term immunogenicity and effectiveness of live attenuated hepatitis A vaccine (H2 strain) after one dose injection could last as long as 15 years.

Vaccination with a human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in Korean girls aged 10-14 years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr.

[Analysis on epidemiological and serum effect after vaccination of hepatitis A vaccine (HepA)]

OBJECTIVE

To implement HepA vaccination and analyze epidemiological and serum effect.

METHODS

The children from 1 to 14 years old were vaccinated HepA since 1992 and the HepA has been integrated into EPI to the children aged 1 year in 1996. The enzyme linked immunnosortbent assay (ELISA) was used to detect Anti-Hepatitis A Virus IgG Antibody (Anti-HAV) to analyze serum effect.

RESULT

HepA coverage rate from 1 to 14 years old was 80% in 1998, and it was > 90% after the year of 2001. The coverage of 1 year old children was 95%. The incidence rate of Hepatitis A reduced continuously. The incidence of whole population reduced from 25.96/100.000 in 1992 to 6.38/100.000 in 1994. In 2007, the incidence of Heptitis A decreased 98.10% compared with the incidence of the year of 1992. Epidemiological feature of Hepatitis A was changed. The positive rate of Anti-HAV was increased after vaccination of Hepatitis A Vaccine.

CONCLUSION

The vaccination strategy for 1 to 14 years old had obviously epidemiological and serum effect.

Randomized trial to determine safety and immunogenicity of two strategies for hepatitis B vaccination in healthy urban adolescents in the United States

BACKGROUND

Multiple studies have shown excellent response rates after hepatitis B immunization in youth; however, one previous study conducted in urban youth demonstrated poor responses.

METHODS

Urban youth, ages 12 to 17 years, at participating Adolescent Medicine Trials Network for HIV/AIDS Interventions Clinical/Research sites were randomized to receive either 2 doses of Recombivax HB (10 microg hepatitis B surface antigen) or Twinrix (20 microg hepatitis B surface antigen and 720 EL.U hepatitis A antigen) at 0 and 24 weeks. Safety data were collected and antibody measures performed at 0, 28, and 76 weeks.

RESULTS

A total of 123 subjects were enrolled and 102 had week 28 serum samples available for antibody measure. A positive response (serum antibody > or =10 mIU/mL) to hepatitis B antigen was documented in 41 of 47 (87.2%; 95% confidence interval [CI] 74.3%-95.2%) Recombivax HB recipients and in 52 of 55 (94.6%; 95% CI, 84.9%-98.9%) Twinrix recipients (P = 0.295). In an adjusted analysis, those identified as Hispanic ethnicity (N = 86) were more likely to have a positive response (odds ratio 7.38, 95% CI, 1.56-34.95; P = 0.0018); whereas those who identified as not heterosexual (N = 9) were less likely to respond (odds ratio = 0.12, 95% CI, 0.02-0.74). The majority of youth in the Twinrix arm were hepatitis A antibody positive at baseline (26/51; 51%); however, 24 of 25 hepatitis A antibody negative youth responded to the hepatitis A component. Both vaccines were safe.

CONCLUSIONS

Response rate to 2 doses of Recombivax HB in urban youth is lower than previous studies suggest. The factors associated with diminished response are not known.

Changing prevalence of anti-hepatitis A virus in adolescents in a rural township in Taiwan

BACKGROUND

Hepatitis A virus (HAV) is transmitted through the oral-anal route. Areas of low prevalence of anti-HAV might have risks for a hepatitis A outbreak even under accidental infection as the source can spread easily. The prevalence of anti-HAV among children in Taipei is reported to be nearly 0%; however, the prevalence in rural areas remains undetermined. Our study aims to realize the prevalence change in a rural area.

METHODS

We took blood samples for anti-HAV detection from the entire junior high school population in Taihsi Township of Yunlin County in Taiwan. Two cross-sectional studies were conducted in 1999 and 2006, with students born in the years 1984-1985 and 1993-1994 respectively.

RESULTS

The prevalence of anti-HAV was 0.96% (2/209) among subjects born between 1984-1985, and 0.6% (1/168) in those born between 1993-1994. The HAV vaccine was not available for at the time of the earlier study, and it is suggested that this figure was caused by natural infection. The only anti- HAV-positive student in the later study had a history of HAV vaccination.

CONCLUSIONS

The prevalence of anti-HAV has decreased to a very low level in recent years and is almost 0% in the generation born after 1984 in rural areas. Therefore, the possibility of an HAV outbreak should be noted. Furthermore, it is also necessary to offer correct information and suggestions concerning hepatitis A for tourists traveling abroad and reentering Taiwan.

[Safety and immunogenicity of combined hepatitis A and hepatitis B vaccine according to 0 and 6 months schedule in healthy children]

OBJECTIVE

To evaluate the safety and immunogenicity of the Bilive(TM) combined hepatitis A and hepatitis B vaccine in healthy children.

METHODS

A total of 116 healthy children aged 1 - 10 years, who, without history of hepatitis A vaccine vaccination and anti-HAV negative, had completed the full immunization of hepatitis B vaccine were recruited in city of Changzhou in Jiangsu province. The Bilive(TM) combined hepatitis A and hepatitis B vaccine was administered according to a two-dose schedule (0, 6 months). The dosage was 250 U for hepatitis A antigen and 5 microg for hepatitis B surface antigen. The potential adverse effects were observed within 72 hours after vaccination. The serum samples were collected for the testing of anti-HAV and anti-HBs at month 1, 6 and 7 after initial dose.

RESULTS

The local and systemic adverse reactions after immunization were slight and temporary. The rates of local and systemic adverse reactions were 12.1% (14/116) and 6.0% (7/116). The sero-conversion rates of HAV were from 92.9% (92/99) to 100.0% (101/101) and the geometric mean titers (GMT) ranged from 47.0 mIU/ml to 2762.3 mIU/ml 1, 6, 7 months after initial dose. The sero-protection rate of HBV was 86.1% (87/101) before vaccination and came up to 100.0% (101/101) one month after initial dose, and the GMTs of HBV were from 894.3 mIU/ml to 3314.3 mIU/ml 1, 6, 7 months after initial dose.

CONCLUSION

The Bilive(TM) combined hepatitis A and hepatitis B vaccine has good safety and immunogenicity in healthy children who had preexisting immunity to hepatitis B virus.

[Assessment of effectiveness and immunogenicity of hepatitis A vaccination in servicemen of Internal Forces of Ministry of Internal Affairs of Russia]

AIM

Comarative assessment of immunological and epidemiological effectiveness of hepatitis A vaccination and duration of immunity after immunization in servicemen.

MATERIALS AND METHODS

During 1996-2003, immunogenicity and epidemiologic effectiveness of 3 vaccines against hepatitis A--Havrix 1440 (GlaxoSmithKline, Belgium), Hep-A-in-Vac (Chumakov Institute of Poliomyelitis and Viral Encephalitides, Russia), and Avaxim (Sanofi Pasteur, France)--were evaluated. More than 15,000 servicemen were immunized during that time. In all cases one-dose vaccination without booster was performed.

RESULTS

Several cases of acute hepatitis A were registered 12 months and 6-8 months after vaccination in military communities immunized with Havrix 1440 and Hep-A-in-Vac vaccines respectively. Usage of Avaxim vaccine as a single dose in field trials allowed to exclude new cases of acute hepatitis A during time of military service. It was shown that 5 years after single vaccination with Avaxim protective anti-HAV antibody level (20 IU/l) persisted in 90% of Internal Forces servicemen.

CONCLUSION

On the basis of performed complex of studies, system of antiepidemic measures was developed, which leads to decrease of hepatitis A incidence. Selective immunization is proposed.

Virologic and immunologic correlates with the magnitude of antibody responses to the hepatitis A vaccine in HIV-infected children on highly active antiretroviral treatment

BACKGROUND

HIV-infected individuals mount poor antibody responses to vaccines. We sought to identify the immunologic and virologic factors associated with a robust response to hepatitis A virus (HAV) vaccine in children on highly active antiretroviral treatment.

METHODS

One hundred fifty-two pediatric highly active antiretroviral treatment recipients immunized against HAV at weeks 0 and 24 had anti-HAV antibodies, CD4+, CD8+, and CD19+ cell percent assessed at weeks 0 and 32. Subgroups had HIV viremia, B- and T-cell subpopulations, and cell-mediated immunity (CMI) to HAV and other stimulants measured.

RESULTS

Anti-HAV antibodies after complete vaccination correlated positively with CD4+ percent and CD19+ percent and negatively with viremia and CD8+ percent at baseline, but not at 32 weeks. There were no significant correlations between anti-HAV antibodies and B- or T-cell-naïve, memory, or activated subpopulations or non-HAV CMI. Compared with children who remained HAV-CMI-negative, those who mounted HAV-CMI in response to vaccination had higher anti-HAV antibody titers and CD19+ CD21+ CD27+ memory B cell percent at 32 weeks, but no other differences.

CONCLUSIONS

In HIV-infected children on highly active antiretroviral treatment, control of viral replication and conserved or reconstituted CD19+ and CD4+ cell numbers and function determine a robust antibody response to anti-HAV primary immunization. Our data support a bidirectional B- and T-cell cooperation in the response to the HAV vaccine.

[The immunogenicity and impact factors of hepatitis A attenuated live vaccine and inactivated vaccine]

Hepatitis A is one of the global public health problems, and China has high prevalence. In order to decrease the incidence of hepatitis A, China has integrated Hepatitis A vaccine into Expanded Program on Immunization (EPI) in 2007. The paper will provide some ideas on the immunogenicity and impact factors of the different types of hepatitis A vaccines that are used in China.

[Comparison of antibody persistence between live attenuated and inactivated hepatitis A vaccines]

OBJECTIVE

To study the antibody persistence of live attenuated hepatitits A vaccine, and to compare the antibody between with inactivated vaccine.

METHODS

211 HAV susceptible children were divided randomly into three groups, Group A was injected three doses HepA-L at 0, 6 and 12 monthes; Group B was administrated two dose HepA-L at 0 and 6 months, and group C was immunized with inactivated vaccine at month 0 and 6. Serum samples were detected for Anti-HAV at 1, 6, 7, 12, 13, 24, 84 months after vaccination in each group.

RESULTS

The seroconversion rates reached 100% after 2nd dose in all groups. The highest GMC was 2938.1 mlU/ml, founded in group C, and it was 1315.6 mlU/ml and 1586 mlU/ml in group A and B respectively. After the 3rd dose at month 12 in group A, the antibody increased dramatic, which reached 1945.3 mlU/ml. 84 months after first dose in each group, the antibody can be detected from all subjects. Though the GMC in group A declined to 336.8 mlU/ml, it was significant higher than that in group B and C.

CONCLUSION

The good booster effect with HepA-L was well observed in a short-term. The immune response induced by 2 to 3 doses HepA-L could compete with inactivated hepatitis A vaccine. However, long-term effects of both vaccines need further study.