Post-Vaccination and Post-Infection Immunity to the Hepatitis B Virus and Circulation of Immune-Escape Variants in the Russian Federation 20 Years after the Start of Mass Vaccination

A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018-2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republic of Dagestan (2.4%, p < 0.0001). Among the generation vaccinated at birth, the average HBsAg detection rate was below 0.3%, ranging from 0% to 0.7% depending on the region. The anti-HBc detection rate in subjects under 20 years was 7.4%, indicating ongoing HBV circulation. The overall proportion of participants under 20 years with vaccine-induced HBV immunity (anti-HBs positive, anti-HBc negative) was 41.7% but below 10% in the Tuva Republic and below 25% in the Sverdlovsk and Kaliningrad regions. The overall prevalence of immune-escape HBsAg variants was 25.2% in sequences obtained from 2018-2022, similar to the prevalence of 25.8% in sequences collected prior to 2010 (p > 0.05). The population dynamics of immune-escape variants predicted by Bayesian analysis have remained stable over the last 20 years, indicating the absence of vaccine-driven positive selection. In contrast, the wild-type HBV population size experienced a rapid decrease starting in the mid-1990s, following the introduction of mass immunization, but it subsequently began to recover, reaching pre-vaccination levels by 2020. Taken together, these data indicate that it is gaps in vaccination, and not virus evolution, that may be responsible for the continued virus circulation despite 20 years of mass vaccination.

Epidemiology of hepatitis B and the role of vaccination

Hepatitis B virus (HBV) is a major cause of morbidity and mortality with a disproportionate impact on Asia and Africa. Current guidelines recommend screening at-risk populations for chronic HBV infection so that diagnosed individuals can be linked to appropriate hepatitis care. The vast majority of infected individuals are undiagnosed and untreated, and are at risk of developing cirrhosis, liver failure, and hepatocellular carcinoma. In individuals who are not yet infected, the HBV vaccine is safe and highly effective at preventing disease transmission. Countries with successful vaccination programs have been able to dramatically reduce their HBV prevalence. A concerted effort to screen, treat, and vaccinate at-risk individuals has the potential to eliminate HBV as a public health threat by 2030.

Adherence to follow-up and treatment recommendations in Greek and immigrant patients with chronic hepatitis B in Greece

BACKGROUND/AIM

Immigrants have multiple barriers to access to health care systems. We evaluated the adherence to follow-up and treatment recommendations of chronic hepatitis B virus (HBV) Greek and immigrant patients.

METHODS

In total, 1001 consecutive adult patients with chronic HBV infection who visited our clinics for the first time between 2002 and 2011 were included. All patients born outside Greece were considered immigrants. Diagnosis was considered to be complete if patients could be classified into HBeAg-positive chronic hepatitis B (CHB), inactive carriers, HBeAg-negative CHB, or decompensated cirrhosis.

RESULTS

Of the patients, 56% were Greeks and 44% were immigrants. Greeks visited our clinics at a significantly older mean age (50 vs. 35 years, P<0.001) and more frequently with advanced liver disease (11.4 vs. 6.4%, P=0.007). During the first year, Greeks more frequently had several tests and eventually a complete diagnosis (68 vs. 55%, P<0.001). Greeks were more frequently in the phase of HBeAg-negative CHB and less frequently in the phase of inactive carrier or HBeAg-positive CHB, but age was the main determinant for these differences in multivariate analysis. Treatment was initiated more frequently by Greeks than immigrants with treatment indications (86 vs. 65%, P<0.001). Only 30-33% of treated and 4-10% of untreated patients remained under follow-up at year 5, without significant differences between Greeks and immigrants.

CONCLUSION

Adherence to follow-up recommendations is rather poor for all chronic HBV patients. Immigrants are lost more frequently during the first year, but only small proportions of treated and particularly untreated Greek or immigrant patients remain under long-term follow-up.

Differences in survival and cause-specific mortality in a culturally diverse Greek population, 1999-2008

BACKGROUND

Modern urban populations exhibit considerable internal heterogeneity. Several social groups, such as ethnic minorities or immigrants, constitute individual clusters with different demographic and epidemiological characteristics.

METHODS

Death records were collected from the Municipality Registry between 1999 and 2008. Kaplan-Meier survival analysis was conducted for (i) natively born Greeks, (ii) former USSR-repatriated Greeks and (iii) Roma. Further evaluation was conducted by log-rank (Mantel-Cox) test. Relative mortality rates were assessed by means of cross-tabulation (Pearson's χ(2)).

RESULTS

Statistically significant differences in median survival were observed among the three social groups (P < 0.001). The relative mortality from infectious diseases was higher in the Roma population compared with natively born Greeks, odds ratio (OR) = 8.31 [confidence interval (CI) 95% 3.19-21.61]. More than 70% of these deaths were attributed to respiratory tract infections and were associated with children under the age of 5. Excess mortality due to external causes, injuries and substance abuse was observed in repatriated males compared with their natively born counterparts, OR = 2.27 (CI 95% 1.35-3.81).

CONCLUSIONS

Specific public health interventions are required, to improve the survival of different cultural groups. For example, improvement of immunization status and increase in overall hygiene awareness can ameliorate high infant/childhood mortality in Roma population, while social integration can help reduce acculturation-related mortality among repatriated Greeks.

Hepatitis B virus infection in children

For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate.

The state of hepatitis B and C in the Mediterranean and Balkan countries: report from a summit conference

The burden of disease due to chronic viral hepatitis constitutes a global threat. In many Balkan and Mediterranean countries, the disease burden due to viral hepatitis remains largely unrecognized, including in high-risk groups and migrants, because of a lack of reliable epidemiological data, suggesting the need for better and targeted surveillance for public health gains. In many countries, the burden of chronic liver disease due to hepatitis B and C is increasing due to ageing of unvaccinated populations and migration, and a probable increase in drug injecting. Targeted vaccination strategies for hepatitis B virus (HBV) among risk groups and harm reduction interventions at adequate scale and coverage for injecting drug users are needed. Transmission of HBV and hepatitis C virus (HCV) in healthcare settings and a higher prevalence of HBV and HCV among recipients of blood and blood products in the Balkan and North African countries highlight the need to implement and monitor universal precautions in these settings and use voluntary, nonremunerated, repeat donors. Progress in drug discovery has improved outcomes of treatment for both HBV and HCV, although access is limited by the high costs of these drugs and resources available for health care. Egypt, with the highest burden of hepatitis C in the world, provides treatment through its National Control Strategy. Addressing the burden of viral hepatitis in the Balkan and Mediterranean regions will require national commitments in the form of strategic plans, financial and human resources, normative guidance and technical support from regional agencies and research.

The burden of liver disease in Europe: a review of available epidemiological data

To survey the burden of liver disease in Europe and its causes 260 epidemiological studies published in the last five years were reviewed. The incidence and prevalence of cirrhosis and primary liver cancer are key to understand the burden of liver disease. They represent the end-stage of liver pathology and thus are indicative of the associated mortality. About 0.1% of Hungarian males will die of cirrhosis every year compared with 0.001% of Greek females. WHO estimate that liver cancer is responsible for around 47,000 deaths per year in the EU. Harmful alcohol consumption, viral hepatitis B and C and metabolic syndromes related to overweight and obesity are the leading causes of cirrhosis and primary liver cancer in Europe. Chronic hepatitis B affects 0.5-0.7% of the European population. In the last decade the prevalence of chronic hepatitis C was 0.13-3.26%. It is of great concern that about 90% of people in Europe infected by viral hepatitis are unaware of their status. Available data suggest the prevalence rate of NAFLD is 2-44% in the general European population (including obese children) and 42.6-69.5% in people with type 2 diabetes. Each of these four major causes of liver disease is amenable to prevention and treatment, reducing the burden of liver disease in Europe and saving lives. Further surveys are urgently needed to implement cost-effective prevention programmes and novel treatments to tackle this problem.

Epidemiology, clinical data, and treatment of viral hepatitis in a large cohort of intravenous drug users

OBJECTIVES

The aim of this study was to evaluate retrospectively the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, epidemiological parameters, and the clinical data from the antiviral treatment of hepatitis C in a large cohort of intravenous drug users (IDUs) followed-up from 1994 until 2008.

PATIENTS AND METHODS

A total of 1179 former IDUs followed up either in the liver unit or in the context of a substitution program organization were included in this study. A retrospective chart review was prepared to retrieve data on the patients' demographic characteristics, the prevalence of viral hepatitis, and information on HCV treatment.

RESULTS

The prevalence of HBsAg positive was 5%. A substantial number of patients were anti-HCV positive (847/1170, 73%), 189 were lost to follow-up, 526 (80%) were HCV RNA positive and 132 (20%) had a self-limited disease. The most prevalent genotype was 3 (59.7%). Twenty-five percent of the study population received antiviral treatment against HCV infection. Patients seen in the Liver Unit were more likely to receive antiviral treatment. The sustained virological response (SVR) was 80% with patients treated with pegylated interferon and ribavirin having a significantly higher SVR rate.

CONCLUSIONS

Our results show that (a) the majority of IDUs in Greece have chronic hepatitis C and the prevalent genotype is 3 (b) patients who complete therapy have SVR rates similar to those without drug-dependence, and (c) since IDUs constitute the core of the hepatitis C epidemic and the main route of HCV transmission, efforts to treat these patients should be made.

Infection with hepatitis B and C viruses and risk of lymphoid malignancies in the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND

Case-control studies suggested a moderate, but consistent, association of hepatitis C virus (HCV) infection with lymphoid tissue malignancies, especially non-Hodgkin lymphoma (NHL). More limited data suggested that hepatitis B virus (HBV) infection might also be associated with NHL. However, prospective studies on the topic are few.

METHODS

A nested case-control study was conducted in eight countries participating in the EPIC prospective study. Seven hundred thirty-nine incident cases of NHL, 238 multiple myeloma (MM), and 46 Hodgkin lymphoma (HL) were matched with 2,028 controls. Seropositivity to anti-HCV, anti-HBc, and HBsAg was evaluated and conditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for NHL, MM, or HL, and their combination.

RESULTS

Anti-HCV seropositivity among controls in different countries ranged from 0% to 5.3%; HBsAg from 0% to 2.7%; and anti-HBc from 1.9% to 45.9%. Similar nonsignificant associations were found with seropositivity to HBsAg for NHL (OR = 1.78; 95% CI: 0.78-4.04), MM (OR = 4.00; 95% CI: 1.00-16.0), and HL (OR = 2.00; 95% CI: 0.13-32.0). The association between HBsAg and the combination of NHL, MM, and HL (OR = 2.21; 95% CI: 1.12-4.33) was similar for cancer diagnosed less than 3 and 3 or more years after blood collection. No significant association was found between anti-HCV and NHL, MM, or HL risk, but the corresponding CIs were very broad.

CONCLUSIONS

Chronic HBV infection may increase the risk of lymphoid malignancies among healthy European volunteers.

IMPACT

Treatment directed at control of HBV infection should be evaluated in HBsAg-seropositive patients with lymphoid tissue malignancies.

Serological markers of Hepatitis B and C among juvenile immigrants from Albania settled in Greece

BACKGROUND

Greece is a place of settlement for a large number of immigrants, particularly from Albania, which constitute special community groups for public health policies.

OBJECTIVES

This study was designed to assess the seroprevalence of serological markers for Hepatitis B and C among juvenile immigrants from Albania settled in Greece.

METHODS

The study population included 504 subjects, 418 males and 86 females, aged 10-23 years old who have emigrated from Albania to Pogoniani-Greece and participated voluntarily in vaccination programmes against Hepatitis B. The serum samples were examined with enzyme immune assays for the immunological markers HBsAg, anti-HBc, anti-HBs and anti-HCV. HBsAg positive samples were further tested for IgM anti-HBc, HBeAg and anti-HBe.

RESULTS

Among the examined subjects, 40.5% were found positive for anti-HBc, indicating an HBV contamination. Specifically, 11.7% were carriers of HBsAg, whereas 28.8% were negative for HBsAg but positive for anti-HBc. Only 6.5% was positive exclusively for anti-HBs. The rest (53.0%) presented no positive serological markers. Among the HBsAg positive patients, 8.5% were found positive for HBeAg, while 5.1% was positive for IgM anti-HBc. Finally, only 0.6% of the sample presented antibodies against HCV.

CONCLUSION

The examined migratory population is described by a high prevalence of Hepatitis B. Therefore, specific public health measures are necessary. However, no data was found that indicate potential public health dangers regarding hepatitis C.