Modeling indicates efficient vaccine-based interventions for the elimination of hepatitis C virus among persons who inject drugs in metropolitan Chicago

Epidemiological study of hepatitis B and hepatitis C infection in Kohgiluyeh and Boyer-Ahmad province (Iran) from 2008 to 2021: A cross-sectional study

Background and Aims

Viral hepatitis is one of the top five reasons people die from infections all around the world. The present study aimed to assess the epidemiological features of hepatitis B and hepatitis C infections in Kohgiluyeh and Boyer-Ahmad province.

Methods

The data were obtained via the census method from the registered hepatitis B and hepatitis C data in the reportable disease care system of Yasuj University of Medical Sciences. The collected data are the result of serological tests. The χ 2 test was used to evaluate the important risk factors for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. The joinpoint regression was performed to investigate the trend of HBV and HCV in recent years.

Results

Here, 1270 cases of hepatitis B and C were identified and reported in Kohgiluyeh and Boyer-Ahmad province from 2008 to 2021. The median age of patients was 38 (interquartile range: 31-51), varying significantly according to the type of hepatitis. The most common hepatitis in males was hepatitis C and in females, hepatitis B. Regarding the place of residence, HBV and HCV were both more prevalent in urban areas. The age group of 25-34 years has the highest prevalence of HBV and HCV. According to the joinpoint regression analysis, there is a decrease in the 14-year trend of incidence rate due to total hepatitis B and C: the annual percent change was -5.2% (95% confidence interval [CI]: -8.4 to -1.9, p = 0.005) for hepatitis B and -0.2% (95% CI: -10.7 to 11.6, p = 0.976) for hepatitis C.

Conclusion

This study shows the incidence rate of hepatitis B has been decreasing during the years of study but this trend has been stable for hepatitis C. Also, the highest number of cases of hepatitis B and C were reported in the age groups of 25-34 years. Hence, preventive interventions are vital in reducing the burden of these diseases.

Current Hepatitis C Vaccine Candidates Based on the Induction of Neutralizing Antibodies

The introduction of direct-acting antivirals (DAAs) has revolutionized hepatitis C treatment. Short courses of treatment with these drugs are highly beneficial to patients, eliminating hepatitis C virus (HCV) without adverse effects. However, this outstanding success is tempered by the continuing difficulty of eradicating the virus worldwide. Thus, access to an effective vaccine against HCV is strongly needed to reduce the burden of the disease and contribute to the elimination of viral hepatitis. The recent failure of a T-cell vaccine based on the use of viral vectors expressing the HCV non-structural protein sequences to prevent chronic hepatitis C in drug users has pointed out that the induction of neutralizing antibodies (NAbs) will be essential in future vaccine candidates. To induce NAbs, vaccines must contain the main target of this type of antibody, the HCV envelope glycoproteins (E1 and E2). In this review, we summarize the structural regions in E1 and E2 proteins that are targeted by NAbs and how these proteins are presented in the vaccine candidates currently under development.

Modeling hepatitis C micro-elimination among people who inject drugs with direct-acting antivirals in metropolitan Chicago

Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease and mortality worldwide. Direct-acting antiviral (DAA) therapy leads to high cure rates. However, persons who inject drugs (PWID) are at risk for reinfection after cure and may require multiple DAA treatments to reach the World Health Organization's (WHO) goal of HCV elimination by 2030. Using an agent-based model (ABM) that accounts for the complex interplay of demographic factors, risk behaviors, social networks, and geographic location for HCV transmission among PWID, we examined the combination(s) of DAA enrollment (2.5%, 5%, 7.5%, 10%), adherence (60%, 70%, 80%, 90%) and frequency of DAA treatment courses needed to achieve the WHO's goal of reducing incident chronic infections by 90% by 2030 among a large population of PWID from Chicago, IL and surrounding suburbs. We also estimated the economic DAA costs associated with each scenario. Our results indicate that a DAA treatment rate of >7.5% per year with 90% adherence results in 75% of enrolled PWID requiring only a single DAA course; however 19% would require 2 courses, 5%, 3 courses and <2%, 4 courses, with an overall DAA cost of $325 million to achieve the WHO goal in metropolitan Chicago. We estimate a 28% increase in the overall DAA cost under low adherence (70%) compared to high adherence (90%). Our modeling results have important public health implications for HCV elimination among U.S. PWID. Using a range of feasible treatment enrollment and adherence rates, we report robust findings supporting the need to address re-exposure and reinfection among PWID to reduce HCV incidence.

Vaccines for immunoprevention of cancer

The immunoprevention of cancer and cancer recurrence is an important area of concern for the scientific community and society as a whole. Researchers have been working for decades to develop vaccines with the potential to alleviate these health care and economic burdens. So far, vaccines have made more progress in preventing cancer than in eliminating already established cancer. In particular, vaccines targeting oncogenic viruses, such as the human papillomavirus and the hepatitis B virus, are exceptional examples of successful prevention of virus-associated cancers, such as cervical cancer and hepatocellular carcinoma. Cancer-preventive vaccines targeting nonviral antigens, such as tumor-associated antigens and neoantigens, are also being extensively tested. Here, we review the currently approved preventive cancer vaccines; discuss the challenges in this field by covering ongoing preclinical and clinical human trials in various cancers; and address various issues related to maximizing cancer vaccine benefit.

Modeling based response guided therapy in subjects with recent hepatitis C infection

BACKGROUND & AIMS

Mathematical modeling of viral kinetics has been shown to identify patients with chronic hepatitis C virus (HCV) infection who could be cured with a shorter duration of direct-acting antiviral (DAA) treatment. However, modeling therapy duration has yet to be evaluated in recently infected individuals. The aim of this study was to retrospectively examine whether modeling can predict outcomes of six-week sofosbuvir (SOF) and weight-based ribavirin (R) therapy in individuals with recent HCV infection.

METHODS

Modeling was used to estimate viral host parameters and to predict time to cure for 12 adults with recent HCV infection (<12 months of infection) who received six weeks of treatment with SOF + R.

RESULTS

Modeling results yielded a 100% negative predictive value for SOF + R treatment response in nine participants and suggested that a median of 13 [interquartile range: 8-16] weeks of therapy would be required for these patients to achieve cure. Modeling predicted cure after 5 weeks of therapy in the only modeled participant who achieved a sustained virological response. However, cure was also predicted for two participants who relapsed following treatment.

CONCLUSIONS

The modeling results confirm that longer than 6 weeks of SOF + R is needed to reach cure in individuals with recent HCV infection. Prospective real-time modeling under current potent DAA regimens is needed to validate the potential of response-guided therapy in the management of recent HCV infection.

Genetically Modified Mouse Mesenchymal Stem Cells Expressing Non-Structural Proteins of Hepatitis C Virus Induce Effective Immune Response

Hepatitis C virus (HCV) is one of the major causes of chronic liver disease and leads to cirrhosis and hepatocarcinoma. Despite extensive research, there is still no vaccine against HCV. In order to induce an immune response in DBA/2J mice against HCV, we obtained modified mouse mesenchymal stem cells (mMSCs) simultaneously expressing five nonstructural HCV proteins (NS3-NS5B). The innate immune response to mMSCs was higher than to DNA immunization, with plasmid encoding the same proteins, and to naïve unmodified MSCs. mMSCs triggered strong phagocytic activity, enhanced lymphocyte proliferation, and production of type I and II interferons. The adaptive immune response to mMSCs was also more pronounced than in the case of DNA immunization, as exemplified by a fourfold stronger stimulation of lymphocyte proliferation in response to HCV, a 2.6-fold higher rate of biosynthesis, and a 30-fold higher rate of secretion of IFN-γ, as well as by a 40-fold stronger production of IgG2a antibodies to viral proteins. The immunostimulatory effect of mMSCs was associated with pronounced IL-6 secretion and reduction in the population of myeloid derived suppressor cells (MDSCs). Thus, this is the first example that suggests the feasibility of using mMSCs for the development of an effective anti-HCV vaccine.

A systematic review and meta-analysis of the prevalence of hepatitis C virus infection in people who inject drugs in Iran

BACKGROUND

Hepatitis C virus (HCV) infection is one of the major public health challenges generating a relevant burden. High-risk groups, including people who inject drugs (PWID), are at serious risk for developing HCV. In recent years, several investigations have been conducted in Iran to assess the prevalence e of HCV among PWID. The aim of the present study was to synthesize the literature performing a comprehensive search and meta-analysis.

METHODS

A comprehensive literature search was carried out from January 2000 to September 2019. Several international databases, namely Scopus, PubMed/MEDLINE, Embase, ISI/Web of Science, PsycINFO, CINAHL, the Cochrane Library and the Directory of Open Access Journals (DOAJ), as well as Iranian databases (Barakathns, SID and MagIran), were consulted. Eligible studies were identified according to the following PECOS (population, exposure, comparison/comparator, outcome and study type) criteria: i) population: Iranian population; ii) exposure: injection drug users; iii) comparison/comparator: type of substance injected and level of substance use, iv) outcome: HCV prevalence; and v) study type: cross-sectional study. After finding potentially related studies, authors extracted relevant data and information based on an ad hoc Excel spreadsheet. Extracted data included the surname of the first author, the study journal, the year of publication, the number of participants examined, the type of diagnostic test performed, the number of positive HCV patients, the number of participants stratified by gender, the reported prevalence, the duration of drug injection practice and the history of using a shared syringe.

RESULTS

Forty-two studies were included. 15,072 PWID were assessed for determining the prevalence of HCV. The overall prevalence of HCV among PWID in Iran was computed to be 47% (CI 95: 39-56). The prevalence ranged between 7 and 96%. Men and subjects using a common/shared syringe were 1.46 and 3.95 times more likely to be at risk, respectively.

CONCLUSION

The findings of the present study showed that the prevalence of HCV among PWIDs in Iran is high. The support and implementation of ad hoc health-related policies and programs that reduce this should be put into action.