Hepatitis B Vaccine

Although a majority of countries in the Middle East show intermediate or high endemicity of hepatitis B virus (HBV) infection, which clearly poses a serious public health problem in the region, the situation in the Republic of Syria remains unclear. The aim of this study is to determine the hepatitis B vaccination status, to assess the number of vaccinations administered, and to estimate the annual incidence of needlestick injuries (NSIs) among healthcare workers (HCWs) in Aleppo University hospitals. A cross-sectional design with a survey questionnaire was used for exploring details of NSIs during 2008, hepatitis B vaccination status, and HBV infection among a random stratified sample of HCWs in three tertiary hospitals in Aleppo (n = 321). Two hundred and forty-six (76.6%) HCWs had sustained at least one NSI during 2008. Nine (2.8%) had HBV chronic infection and 75 HCWs (23.4%) were never vaccinated. Anesthesiology technicians had the greatest exposure risk when compared to office workers [OR = 16,95% CI (2.55-100), P < 0.01], doctors [OR = 10,95% CI (2.1 47.57), P < 0.01], and nurses [OR = 6.75,95% CI (1.56-29.03), P = 0.01]. HCWs under 25 and between the age of 25 and 35 years were at increased risk for NSI when compared to HCWs older than 45 years [OR = 3.12,95% CI (1.19-8.19), P = 0.02] and [OR = 3.05,95% CI (1.42-6.57), P < 0.01], respectively. HCWs at Aleppo University hospitals are frequently exposed to blood-borne infections. Precautions and protection from NSIs are important in preventing infection of HCWs. Education about the transmission of blood-borne infections, vaccination, and post-exposure prophylaxis must be implemented and strictly monitored.

Background In 2002, a poster alerted the French health authorities to the possibility that the risk of childhood leukaemia might be increased by hepatitis B vaccination. Elucidating the role of vaccination in the aetiology of childhood acute leukaemia (AL) was therefore included in the objectives of an ongoing national study. Methods The ESCALE study was a French national population-based case-control

Current hepatitis B vaccination programmes targeting risk groups have met with little success in controlling HBV infection in the general population. Despite the long-standing existence of unambiguous recommendations for risk-group vaccination, hepatitis B vaccination coverage remains low in most risk groups in most high-income countries. This low coverage may be attributed to a lack of perceived risk of hepatitis B and the absence of appropriate health care programmes targeting hepatitis B monitoring and vaccination for certain risk groups, particularly sex workers, injecting drug users, and prisoners. The Viral Hepatitis Prevention Board (VHPB) recognises the importance of raising the awareness of health care providers, policymakers, and the general public, about hepatitis B as a risk to both the community in general and to specific groups considered at increased risk. The VHPB also recognises that new strategies will have to be developed and implemented.

At the age of two years, Jeanett developed vitiligo within days of receiving her first MMR vaccine and the fourth injection of DTaP and IPV vac- cines. Furthermore, at five years of age, she developed many more unpigmented spots on her body with acrofacial vitiligo, following receipt of the second injection of MMR and the fifth injection of DTaP and

Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg). Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs), to elicit the required protective immune response. So far, no clear evidence has been presented showing whether HBsAg assembles in vivo inside the yeast cell into VLPs or later in vitro during down-stream processing and purification. Results High level production of HBsAg was carried out with recombinant Pichia pastoris using the methanol inducible AOX1 expression system. The recombinant vaccine was isolated in form of VLPs after several down-stream steps from detergent-treated cell lysates. Search for the intracellular localization of the antigen using electron microscopic studies in combination with immunogold labeling revealed the presence of HBsAg in an extended endoplasmic reticulum where it was found to assemble into defined multi-layered, lamellar structures. The distance between two layers was determined as ~6 nm indicating that these lamellas represent monolayers of well-ordered HBsAg subunits. We did not find any evidence for the presence of VLPs within the endoplasmic reticulum or other parts of the yeast cell. Conclusions It is concluded that high level production and intrinsic slow HBsAg VLP assembly kinetics are leading to retention and accumulation of the antigen in the endoplasmic reticulum where it assembles at least partly into defined lamellar structures. Further transport of HBsAg to the Golgi apparatus is impaired thus leading to secretory pathway disfunction and the formation of an extended endoplasmic reticulum which bulges into irregular cloud-shaped formations. As VLPs were not found within the cells it is concluded that the VLP assembly process must take place during down-stream processing after detergent-mediated disassembly of HBsAg lamellas and subsequent reassembly of HBsAg into spherical VLPs.

Molecular farming in plants may provide a tempting, safe and inexpensive alternative to conventional protein production. Transgenic plants can produce unlimited amounts of recombinant proteins - subunit vaccines, human pharmaceutical protein, recombinant antibodies and industrial enzymes. Plants have many advantages over the other production systems - scalability, safety and economy. Here we present data showing the production of hepatitis B nucleocapsid antigen (HBcAg) in transgenic tobacco. Enzyme linked immunosorbent assay (ELISA) confirmed the presence of the viral core antigen in the total protein extracts from tobacco leaves.

Facing the discontinuation of the Auszyme kit, an alternative is needed for determining the in vitro potency of Hepatitis B surface antigen in vaccines. An inhibition ELISA has already proven to be reliable, but not in vaccine combinations. We validated this method by the ...

Background In Italy, HBV vaccination is recommended and offered free of charge through the National Health Service to selected population groups – e.g., family members of an HBsAg carrier, healthcare workers, newborns and those who were 12-years old in 1991. However, a significant proportion of cases of acute hepatitis B still occur in Italy among persons who should have been vaccinated. We analysed HBV sero-prevalence data of two vaccination target populations (people born after 1980 and household contacts of an HBV carrier) living in a southern Italian area in order to evaluate HBV vaccine coverage and its possible determinants. Methods Between 2003 and 2006, we carried out a cross-sectional, population-based, sero-epidemiological survey on HBV infection on 4496 randomly selected individuals (aged 20 years or more) from the general population of the province of Naples. Sera were tested for antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis B surface antigen (anti-H...

At the age of two years, Jeanett developed vitiligo within days of receiving her first MMR vaccine and the fourth injection of DTaP and IPV vac- cines. Furthermore, at five years of age, she developed many more unpigmented spots on her body with acrofacial vitiligo, following receipt of the second injection of MMR and the fifth injection of DTaP and

To assess risk factors for decreased immunogenicity among adults vaccinated with hepatitis B vaccine and to determine the importance of differences in immunogenicity between vaccines among health care workers (HCWs). Randomized clinical trial and decision analysis. HCSw. Development of seroprotective levels of antibody to hepatitis B surface antigen (anti-HBs) and the number of expected chronic hepatitis B virus (HBV) infections associated with lack of protection. Overall, 88% of HCWs developed seroprotection. Risk factors associated with failure to develop seroprotection included increasing age, obesity, smoking and male gender (P < .05). Presence of a chronic disease was associated with lack of seroprotection only among persons > or = 40 years of age (P < .05). The two vaccines studied differed in their overall seroprotection rates (90% vs. 86%; P < .05), however, this difference was restricted to persons > or = 40 years of age (87% vs. 81%; P < .01). Among HCWs ...