View clinical trials related to Hepatitis B.
Filter by:GSK Biologicals' currently licensed multidose hepatitis B vaccine will be compared to the currently licensed monodose hepatitis B vaccine in a population with well documented hepatitis B immunological response to the vaccine (Belgium).
To evaluate the persistence of anti-hepatitis A virus (anti-HAV) and anti-hepatitis B surface antigen (anti-HBs) antibodies up to 6, 7, 8, 9 and 10 years after administration of the first dose of the study vaccine.
The purpose of the study is to compare the effectiveness of 3 different treatment regimens in reducing or clearing the Hepatitis B Virus in patients infected with HIV and Hepatitis B (co-infection)
The literature suggests that there may be an association between hepatitis C and type 2 diabetes mellitus independent of the presence of cirrhosis, the likely mechanism for which is insulin resistance. The prevalence of insulin resistance in patients with hepatitis C is unknown. Furthermore, there are no studies that indicate an increased prevalence of insulin resistance in patients with hepatitis C compared to other etiologies of liver disease. The role that hepatitis C may have in the development of insulin resistance is unclear. The effect of antiviral therapy for hepatitis C virus on insulin resistance has not been addressed. The long-term consequence of insulin resistance is type 2 diabetes mellitus. There is significant morbidity and mortality from type 2 diabetes mellitus in the general population, and similar complications would be expected in patients with hepatitis C and insulin resistance particularly if they develop type 2 diabetes mellitus. Our hypothesis: The prevalence of insulin resistance is increased in patients with chronic hepatitis C compared to chronic hepatitis B. Secondarily, insulin resistance when present in patients with chronic hepatitis C improves with successful antiviral therapy. This study has two phases. The first phase of our study will be to estimate the prevalence of insulin resistance in individuals with chronic hepatitis C without cirrhosis compared to patients with chronic hepatitis B without cirrhosis. The second phase of the study will be restricted to those patients with hepatitis C found to be insulin resistant from phase 1, in the absence of known risk factors for insulin resistance (cirrhosis, diabetes). The effect on insulin resistance of anti-viral therapy to eradicate hepatitis C will be assessed.
The estimated global prevalence of hepatitis C (HCV) infection is approximately 3% (170 million individuals). In Canada there are an estimated 240,000 people infected with HCV. The current study addresses the hypothesis that neurocognitive and neurochemical abnormalities may occur in individuals with HCV-infection who do not have liver cirrhosis or vasculitic neuropathy, and this may result from a direct effect of HCV on the Central Nervous System (CNS). The purpose of this study is to assess whether infection with the Hepatitis-C virus is associated with changes in thinking skills and brain chemistry, in patients who do not have liver cirrhosis. In addition, we are examining whether such changes in thinking skills and brain chemistry are reversed by antiviral treatment. We are also studying whether factors such as fatigue and depression have an effect on thinking skills in people with Hepatitis-C. In order to take into account the impact of having viral hepatitis, we will be comparing the results of the Hepatitis-C group to the results of a group of patients with Hepatitis-B, and to a group of individuals who do not have Hepatitis.
Does vaccinating hemodialysis patients with Twinrix® (combination vaccine against hepatitis A and hepatitis B) result in a difference in hepatitis B antibody response in comparison to the monovalent hepatitis B vaccine? Hepatitis B infection is an important cause of mortality and morbidity. Current standard vaccination practices have low efficacy levels in patients (eg. hemodialysis patients) who are most susceptible of infection. Efficacy of the two regiments will be studied.
This study will look at what happens to the level of protection against hepatitis B (HB) disease if a 'helper' gel is applied to the skin over the injection site of a small dose of hepatitis B vaccine.
Taiwan is an endemic region for hepatitis B. Before the implementation of a nationwide vaccination program in 1984, the hepatitis B virus (HBV) carrier rate in the general population was 15 to 20%.1-2 The major impact of hepatitis B (HB) infection is its long-term sequelae which may include chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma.3 Perinatal infection accounts for 40-50% of all hepatitis B infections and is responsible for the generation-to-generation transmission of HB virus.4 Hepatitis B vaccines, both plasma derived and recombinant, are highly immunogenic and efficacious.5-10 It has been reported that HB vaccine given soon after birth is able to protect infants from perinatal infection and HB infection became the first disease model to show that mother-to-neonate transmission can be interrupted by an effective vaccine.11 Taiwan started a national program of HB vaccination since 1984. This program resulted in a significant reduction of the HB carrier rate in children aged below 10 years from 9.8% before nationwide vaccination to 1.3% after the program.12 It also decreased the incidence of hepatocellular carcinoma in children aged 6 to 9 years from 0.52 to 0.13 per 100,000.13 However, the duration of protection provided by the HB vaccine and the proper timing of a booster dose remains unclear. Because the HB vaccine is a subunit protein vaccine, which contains only HBsAg, a limited duration of protection is anticipated. The results of several long-term follow-up studies of the protective efficacy of HB vaccination have been published. Soon after vaccination, protective levels of antibody (anti-HBs >10 mIU/mL) can be detected in the great majority (83-99%) of vaccinees.5-7 The proportion of vaccinees with protective anti-HBs levels decreases to 75-87% 5 years after vaccination and further drops to 50 to 70% 10-12 years after.10,11,14,15,19-21 Because of the progressive decline of anti-HBs and the associated increased likelihood of development of new HBV infections, some investigators advise the use of a booster vaccination.20,21 However, a preponderance of data indicates that the protective efficacy of the HB vaccine can last for at least 5 to 10 years and a booster before 5 years is not necessary.16-18,22,23 By demonstrating significant augmentation of cellular immunity and adequate induction of a protective level of antiHBs (>10 mIU/ml) in HBsAg and HBeAg-positive subjects 10 years after HB vaccination, we also proved that protection afforded by HB vaccination persisted for no less than 10 years in all vaccinees.R Nevertheless, the protective efficacy after the period of 10 years remains unknown. Knowledge of the duration of protection of HB vaccine and the optimal timing of booster vaccination remains crucial. In this study, we are going to examine the humoral and cellular immunity and monitored the antibody response following a booster dose of HB vaccine in a group of children whom had been vaccinated 14 years prior to this study.
Hepatitis B immunization has been offered to all grade 4 students (age 9-10) in the province of Quebec, using Engerix-B at a dose of 10 mkg. The peak incidence of hepatitis B occurs between age 15 and 35; the proportion of vaccinated children who will still be protected at this age is currently unknown. This study is designed to determine: - persistence of immunity until age 25 - persistence of immunological memory as demonstrated by an anamnestic response following a booster dose - the effect of a booster dose on immunogenicity at either 5, 10 or 15 years after the primary vaccination course (at age (15, 20 or 25).
To assess the immune memory following primary vaccination of DTPw-HBV/Hib vaccine and to assess immunogenicity and reactogenicity of a booster dose given at 15 - 18 months of age.