The Seroconversion Rate of Hepatitis A Virus Vaccination among Patients with Hepatitis B Virus-Related Chronic Liver Disease in Korea

Vaccination in adult liver transplantation candidates and recipients

In patients with chronic liver disease and liver transplant recipients, cirrhosis-associated immune dysfunction syndrome and immunosuppressant drug regimens required to prevent graft rejection lead to a high risk of severe infections, associated with acute liver decompensation, graft loss and increased mortality. In addition to maintain their global health status, vaccination represents a major preventive measure against specific infectious risks of particular concern in this population, such as invasive pneumococcal diseases, influenza or viral hepatitis A and B. However, immunization in this setting raises several issues: i) recommended vaccination schedules rely on sparse immunogenicity data without clinical efficacy and effectiveness trials designed for this specific population; ii) dynamics of immunosuppression makes timing of immunization challenging; iii) live attenuated vaccines are contraindicated after transplantation; and iv) vaccines tolerance is poorly known in cirrhotic patients. This review outlines the rational for vaccination in adult liver transplant candidates and recipients and available data regarding immunization in this specific population.

A study of hepatitis A virus seropositivity among children aged between 1 and 5 years of age: Implications for universal immunization

Background

Hepatitis A virus (HAV) causes an enterically transmitted viral disease mainly affecting children and endemic in many developing countries, including India. There is an epidemiological shift with an increased incidence of symptomatic cases among children. This study was conducted to assess the seroprevalence of HAV among young children aged below 5 years and the need for universal immunization.

Method

This cross-sectional study was conducted at two tertiary care hospitals in Northern India, from Apr 2014 to Jul 2015, among healthy children aged between 1 and 5 years. The sample size was calculated based on the prevalence of HAV seropositivity of 40% among children aged <10 years [16-60%] and alpha error of 5%. Analysis of serum IgG against HAV was performed by enzyme-linked immunosorbent assay method, and results were analyzed.

Results

A total of 1084 children aged between 12 and 60 months were enrolled, with male-to-female ratio of 1.86:1. A total of 471 children (43.5%) were found to be positive for IgG against HAV. The seroprevalence of HAV was lower among younger children aged 12-23 months (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.52-0.87, p = 0.03), which was statistically significant. Seropositivity of HAV was lower among boys and families consuming safe drinking water and having improved sanitation facilities.

Conclusion

The study observed lower seropositivity against HAV among younger children, making them susceptible of contracting the disease. Possible underlying risk factors were younger age, unsafe drinking water, poor sanitation, and low education status of parents. Therefore, vaccination may be recommended as optional vaccine at one year of age, along with improved public health efforts for safe drinking water, hygiene practices, and food safety.

Hepatitis A seroprevalence in patients with chronic viral hepatitis in Konya, Turkey

AIM

Hepatitis A is among the diseases that can be prevented with vaccination in our time. Acute hepatitis A progresses more severely in individuals with a liver disease. Therefore, patients with a chronic liver disease (because of hepatitis B or hepatitis C) are advised vaccination with the hepatitis A vaccine. This study is aimed to determine the seroprevalence of hepatitis A virus (HAV) antibodies in patients infected with hepatitis C virus or hepatitis B virus in Konya province of Turkey.

METHODS

A total of 537 patients who had chronic viral hepatitis between January 2011 and December 2014 were included in the study. Serum samples were collected from each patient and tested for anti-HAV using the chemiluminescent microparticle immunoassay.

RESULTS

The overall seroprevalence of total anti-HAV IgG was 94.2%. The overall prevalence of anti-HAV IgG in patients with chronic hepatitis B virus and hepatitis C virus infection was 97.5 and 93.6%, respectively. Anti-HAV IgG positivity was 97.4% in cirrhotic patients and 93.9% in noncirrhotic individuals.

CONCLUSION

At the end of the study, being older than 40 years and living in a rural area were found to be independent risk factors for anti-HAV IgG seropositivity. In conclusion, we recommend that patients younger than 40 years and/or those living in cities and having a chronic liver disease should be vaccinated with the hepatitis A vaccine.

Association of CMV, HBV, or HCV co-infection with vaccine response in adults with well-controlled HIV infection

Even after CD4 count recovery on antiretroviral therapy, HIV infection is associated with decreased response to most vaccines compared to the general population. Chronic infections with viruses such as cytomegalovirus (CMV), hepatitis B virus (HBV), and hepatitis C virus (HCV), which are more prevalent in HIV-infected populations, have been linked to immune dysfunction and decreased vaccine response in the general population. However, whether co-infection with these other viruses contributes to the decreased vaccine response seen in adults with well-controlled HIV infection is unknown. We conducted a secondary analysis of data and serum from adults with well-controlled HIV infection from an inactivated polio vaccine trial (224 subjects) and a pneumococcal conjugate vaccine study (128 subjects). We evaluated the association of CMV, HBV, or HCV co-infection with post-vaccination antibody levels using both univariate and multivariate analyses, controlling for factors such as age, race, CD4 count, comorbidities, smoking status, and baseline antibody levels. Ninety-three percent, 7%, and 14% of subjects were co-infected with CMV, HBV, and HCV respectively. On both univariate and multivariate analysis, neither CMV nor HCV co-infection were significantly associated with post-vaccination antibody levels to either vaccine. HBV co-infection was significantly associated with post-vaccination antibody concentrations for pneumococcal serotype 7F on univariate analysis and 6A on multivariate analysis, but the association was with higher antibody concentrations. In conclusion, co-infection with CMV, HBV, or HCV does not appear to contribute to the decreased vaccine response seen in adults with well-controlled HIV infection.

Quasispecies structure, cornerstone of hepatitis B virus infection: Mass sequencing approach

Hepatitis B virus (HBV) is a DNA virus with complex replication, and high replication and mutation rates, leading to a heterogeneous viral population. The population is comprised of genomes that are closely related, but not identical; hence, HBV is considered a viral quasispecies. Quasispecies variability may be somewhat limited by the high degree of overlapping between the HBV coding regions, which is especially important in the P and S gene overlapping regions, but is less significant in the X and preCore/Core genes. Despite this restriction, several clinically and pathologically relevant variants have been characterized along the viral genome. Next-generation sequencing (NGS) approaches enable high-throughput analysis of thousands of clonally amplified regions and are powerful tools for characterizing genetic diversity in viral strains. In the present review, we update the information regarding HBV variability and present a summary of the various NGS approaches available for research in this virus. In addition, we provide an analysis of the clinical implications of HBV variants and their study by NGS.