Mathematical modelling of HBV morbidity and mortality, and impacts of hepatitis B immunization
Introduction and background
This request for proposals (RFP) is made by the WHO Initiative for Vaccine Research (IVR)*. IVR seeks proposals for mathematical modelling of hepatitis B-related morbidity and mortality and encourages proposals that include collaboration between institutions/groups in industrialized countries and institutions/groups in low and middle-income countries.
Hepatitis B virus (HBV) infection is a major public health problem worldwide. According to recent estimates approximately 30% of the world’s population i.e. about 2 billion persons have serologic evidence of current or past HBV infection. HBV infection can cause liver diseases including subclinical infection of the liver, acute self-limited hepatitis, and fulminant hepatitis. HBV is also a major human carcinogen and the sequelae of chronic HBV infection are cirrhosis and primary liver cancer (hepatocellular carcinoma, HCC).
A safe and effective vaccine against hepatitis B has been available since 1982 and prevents HBV infections when it is given before or shortly after exposure. The vaccine has also been associated with reductions in the incidence and mortality from HCC in time series analyses.
The World Health Organization (WHO) recommends the integration of HBV vaccine into routine national immunization programs and the universal administration of a HBV dose within 24 hours of birth. The timely administration of HBV vaccine at birth followed by at least two other timely doses can prevent up to 95% of mother-to-child transmission that would have occurred without vaccine. Despite the implementation of these recommendations, HBV vaccine implementation varies across countries.
*IVR's mission is to guide, provide vision, enable, support, and facilitate the development, clinical evaluation and worldwide access to safe, effective and affordable vaccines against infectious diseases of public health importance, especially in developing countries.