Optimising diagnosis of viraemic hepatitis C infection: the development of a target product profile
BMC INFECTIOUS DISEASES
Authors: Reipold, Elena Ivanova; Easterbrook, Philippa; Trianni, Alessandra; Panneer, Nivedha; Krakower, Douglas; Ongarello, Stefano; Roberts, Teri; Miller, Veronica; Denkinger, Claudia
Abstract
Background: The current low access to virological testing to confirm chronic viraemic HCV infection in low- and middle-income countries (LMIC) is limiting the rollout of hepatitis C (HCV) care. Existing tests are complex, costly and require sophisticated laboratory infrastructure. Diagnostic manufacturers need guidance on the optimal characteristics a virological test needs to have to ensure the greatest impact on HCV diagnosis and treatment in LMIC. Our objective was to develop a target product profile (TPP) for diagnosis of HCV viraemia using a global stakeholder consensus-based approach. Methods: Based on the standardised process established to develop consensus-based TPPs, we followed five key steps. (i) Identifying key potential global stakeholders for consultation and input into the TPP development process. (ii) Informal priority-setting exercise with key experts to identify the needs that should be the highest priority for the TPP development; (iii) Defining the key TPP domains (scope, performance and operational characteristics and price). (iv) Delphi-like process with larger group of key stakeholder to facilitate feedback on the key TPP criteria and consensus building based on pre-defined consensus criteria. (v) A final consensus-gathering meeting for discussions around disputed criteria. A complementary values and preferences survey helped to assess trade-offs between different key characteristics. Results: The following key attributes for the TPP for a test to confirm HCV viraemic infection were identified: The scope defined is for both HCV detection as well as confirmation of cure. The timeline of development for tests envisioned in the TPP is 5 years. The test should be developed for use by health-care workers or laboratory technicians with limited training in countries with a medium to high prevalence of HCV (1.5-3.5% and > 3.5%) and in high-risk populations in low prevalence settings (< 1.5%). A clinical sensitivity at a minimum of 90% is considered sufficient (analytical sensitivity of the equivalent of 3000 IU/ml), particularly if the test increases access to testing through an affordable price, increase ease-of-use and feasibility on capillary blood. Polyvalency would be optimal (i.e. ability to test for HIV and others). The only characteristic that full agreement could not be achieved on was the price for a virological test. Discussants felt that to reach the optimal target price substantial trade-offs had to be made (e.g. in regards to sensitivity and integration). Conclusion: The TPP and V&P survey results define the need for an easy-to-use, low cost test to increase access to diagnosis and linkage to care in LMIC.
Enhanced cell immune responses to hepatitis c virus core by novel heterologous DNA prime/lambda nanoparticles boost in mice
VIRUS GENES
Authors: Saeedi, Atefeh; Ghaemi, Amir; Tabarraei, Alijan; Moradi, Abdolvahab; Gorji, Ali; Semnani, Shahryar; Soleimanjahi, Hoorieh; Adli, Ahmad Hosseinzadeh; Hosseini, Seyed Yones; Vakili, Mohammad Ali
Abstract
Hepatitis C virus (HCV) is a worldwide problem which does not have an effective vaccine and more than 170 million people worldwide are chronically infected by HCV. T cell responses are associated with spontaneous clearance of HCV infection. We report here the development of recombinant Lambda bacteriophage nanoparticles encoding HCV Core antigen. The aim of this study was to investigate the antigen-specific immune responses triggered in mice by different prime-boost combinations of DNA and Lambda phage nanoparticles encoding the HCV Core. The homologous prime/boost with recombinant Lambda nanoparticles induced higher levels of cellular and humoral immune response than the DNA vaccines. However, a heterologous prime/boost of HCV Core protein, using DNA vaccine priming followed by Lambda boost, induced highest level of lymphocyte proliferation, CD8 lymphocytes with cytotoxic function, and shifting the immune response toward a T helper (Th1) pattern and in overall improved immunity. Our study provides a new, safe, and effective vaccine for the prime-boost regimen which augments robust immunity and highlights novel promising strategies in HCV vaccine development.