Era of vaccination heralds a decline in incidence of hepatitis A in high-risk groups in China

Review of long term immunogenicity and tolerability of live hepatitis A vaccine

Hepatitis A represents one of the major public health problems worldwide including India. Vaccination is the most effective way to prevent hepatitis A infection. Two types of hepatitis A vaccines-live attenuated (H2 strain) and inactivated (killed) are available for use in clinical practice in India with former having advantage of a single-dose compared to two-dose killed vaccine. One of the important characteristic of an ideal vaccine includes its ability to provide life-long protection. In this article we reviewed the available long-term (≥10 years follow-up) published data on live attenuated hepatitis A (H2 strain) vaccine. The data from country of origin of the vaccine (China) and India establish the long-term immunogenicity, protection, and tolerability. Based on the results of several clinical trials showing long-term protection, single dose of live attenuated hepatitis vaccine can be widely used to protect high-risk population against hepatitis A virus infection and related complications.

Usability of the international HAVNet hepatitis A virus database for geographical annotation, backtracing and outbreak detection

HAVNet is an international laboratory network sharing sequences and corresponding metadata on hepatitis A virus in an online database. Aim: We give an overview of the epidemiological and genetic data and assess the usability of the present dataset for geographical annotation, backtracing and outbreak detection. Methods: A descriptive analysis was performed on the timeliness, completeness, epidemiological data and geographic coverage of the dataset. Length and genomic region of the sequences were reviewed as well as the numerical and geographical distribution of the genotypes. The geographical signal in the sequences was assessed based on a short common nt stretch using a 100% identity analysis. Results: The 9,211 reports were heterogeneous for completeness and timeliness, and for length and genomic region of the sequences. Some parts of the world were not represented by the sequences. Geographical differences in prevalence of HAV genotypes described previously could be confirmed with this dataset and for a third (1,075/3,124) of the included sequences, 100% identity of the short common sequence coincided with an identical country of origin. Conclusion: Analysis of a subset of short, shared sequences indicates that a geographical annotation on the level of individual countries is possible with the HAVNet data. If the current incompleteness and heterogeneity of the data can be improved on, HAVNet could become very useful as a worldwide reference set for geographical annotation and for backtracing and outbreak detection.

Changing incidence of reported viral hepatitis in China from 2004 to 2016: an observational study

OBJECTIVE

China's national hepatitis burden is high. This study aims to provide a detailed national-level description of the reported incidence of viral hepatitis in China during 2004-2016.

DESIGN

Observational study.

SETTING

Data were obtained from China's National Notifiable Disease Reporting System, and changing trends were estimated by joinpoint regression analysis.

PARTICIPANTS

In this system, 16 927 233 reported viral hepatitis cases occurring during 2004-2016 were identified.

PRIMARY OUTCOME MEASURE

Incidence rates per 100 000 person-years and changing trends were calculated.

RESULTS

There were 16 927 233 new cases of viral hepatitis reported in China from 2004 to 2016. Hepatitis B (HBV) (n=13 543 137, 80.00%) and hepatitis C (HCV) (n=1 844 882, 10.90%) accounted for >90% of the cases. The overall annual percent change (APC) in reported cases of viral hepatitis and HBV were 0.3%(95% CI -2.0 to 0.8, p=0.6) and -0.2% (95% CI -1.6 to 1.2, p=0.8), respectively, showing a stable trend. HBV rates were highest in the 20-29 year old age group and lowest in younger individuals, likely resulting from the universal HBV vaccination. The reported incidence of HCV and hepatitis E (HEV) showed increasing trends; the APCs were 14.5% (95% CI 13.1 to 15.9, p<0.05) and 4.7% (95% CI 2.8 to 6.7, p<0.05), respectively. The hepatitis A (HAV) reporting incidence decreased, and the APC was -13.1% (95% CI -15.1 to -11.0, p<0.05). There were marked differences in the reporting of hepatitis among provinces.

CONCLUSIONS

HBV continues to constitute the majority of viral hepatitis cases in China. Over the entire study period, the HBV reporting incidence was stable, the HCV and HEV incidence increased and the HAV incidence decreased. There were significant interprovincial disparities in the burden of viral hepatitis, with higher rates in economically less-developed areas. Vaccination is important for viral hepatitis prevention and control.

A review of immunogenicity and tolerability of live attenuated Hepatitis A vaccine in children

Changing epidemiology of Hepatitis A virus (HAV) has led to an increased susceptibility of adolescents and adults to the infection. Vaccination can remarkably reduce the incidence and associated morbidity of HAV infection. This review is focused on the safety and efficacy of H2 strain derived live attenuated Hepatitis A vaccine. We found the vaccine to be highly immunogenic with minimal or negligible safety issues. Moreover, a single dose of live attenuated vaccine persists a long term immune response and can be a preferred option for developing countries. In 2014, Indian Academy of Paediatrics (IAP) also updated their recommendations for H2 vaccine as a single dose as against the previous 2 dose schedule. A focused approach to include the vaccine in national immunization program should be explored.

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).

Systematic review and meta-analysis on the age-specific seroprevalence of hepatitis A in Iran

BACKGROUND

Hepatitis A virus (HAV) is a major cause of acute viral hepatitis worldwide. Annual medical and work loss costs of hepatitis A are significant even in low-endemic countries. It is recommended that each country should collect and review the information needed to estimate its national burden of hepatitis A to provide evidence for health policy makers to implement appropriate and cost-effective preventive strategy for HAV infection. The objective of this study was to estimate accurate prevalence of HAV infection in Iran for best preventive measures.

MATERIALS AND METHODS

MEDLINE, Institute of Scientific Information, Scopus, Iranmedex, Irandoc, Magiran and Scientific Information Database were searched. The seroprevalence of HAV were pooled by age, sex and residence using fixed and random effect models.

RESULTS

Sixteen papers representing 11857 subjects were included. The overall HAV seroprevalence was 51% (confidence interval [CI] 95%: 50-52%) in fixed and 66% (95% CI: 50-79%) in random effects models. The prevalence was 32% (CI 95%: 11-63%) in less than 20, 50% (CI 95%: 24-75%) in 20-30, and 67% (CI 95%: 17-95%) in more than 30 years of age. The difference was not significant in gender or residence subgroups.

CONCLUSION

HAV infection in Iran may be considered as low or very low. Therefore, targeted vaccination of high-risk groups and more improvement in environmental sanitation would be the best preventive measure.