ABSTRACT
OBJECTIVE: Hepatitis B (HBV) is a viral illness that chronically infects 240 million people worldwide, leads to liver disease, and increases risk of hepatocellular carcinoma. The HBV vaccine has decreased HBV infection, and it and the human papilloma virus vaccine are the only vaccines that prevent cancer. Despite the effectiveness of the HBV vaccine, some populations do not develop protective responses. The risk groups for poor response include those with immunosuppression or dialysis-dependent, end-stage renal disease. Five percent of normal people do not have a response. These subjects are deemed HBV "nonresponders." Multiple strategies to improve the immunogenicity of the HBV vaccine are currently being pursued, including vaccine adjuvants, recombinant vaccines, and immune enhancement via up-regulation of dendritic cells. DATA SOURCES: PubMed was searched for peer-reviewed publications published from January 1980 to September 2017. STUDY SELECTIONS: Studies retrieved for inclusion summarized potential mechanisms behind HBV vaccine nonresponsiveness and potential solutions. RESULTS: The mechanisms behind HBV vaccine nonresponsiveness vary between each subject population. Many current and future strategies may provide protective immunity against HBV in each of these populations. CONCLUSION: This review provides a background on the immunology of HBV infection, the possible immunologic mechanisms to explain HBV vaccine nonresponsiveness, current research aimed at improving vaccine effectiveness, and possible future approaches for providing nonresponders protection from HBV.
Subject(s)
Hepatitis B Vaccines/immunology , Hepatitis B/epidemiology , Hepatitis B/prevention & control , Liver Neoplasms/prevention & control , CD4-Positive T-Lymphocytes/immunology , Celiac Disease/immunology , Diabetes Mellitus/immunology , HIV Infections/immunology , Hepatitis B/immunology , Hepatitis C/immunology , Humans , Kidney Failure, Chronic/immunology , Liver Neoplasms/virology , Lymphocyte Count , Vaccine PotencyABSTRACT
INTRODUCTION: The classification of asthma into phenotypes and endotoypes allows for the use of targeted therapies, including three biologics which target interleukin 5 (IL-5) signaling in eosinophilic asthma. Areas covered: As of December 2016, two monoclonal antibodies, mepolizumab and reslizumab, are approved by U.S. Food and Drug Administration and one, benralizumab, is in clinical development. Two phase 3 trials for benralizumab, SIROCCO and CALIMA, were published in September 2016. Although there are no direct comparisons among these three anti-IL-5 therapies, the goal of this review is to summarize the current data and discuss their potential similarities and differences, with a focus on benralizumab. Expert commentary: Compared to mepolizumab and reslizumab, the possible advantages of benralizumab are less frequent dosing and a potential to reduce exacerbations irrespective of the blood eosinophil count. Some improvements in asthma symptom scores and quality of life occur with all three biologics, but the clinical meaningfulness of these improvements is less clear. A more defined reference range for eosinophil levels is necessary to determine which subjects will best benefit from these medications. Until quality randomized controlled trials directly compare the three, choosing among them for the treatment of eosinophilic asthma remains difficult.