Hepatitis B virus prevalence and vaccination response in health care workers and students at the Federal University of Bahia, Brazil

Background and rationale for the study. Hepatitis B (HB) is one of the most prevalent occupational infections in health attendance environments. According to the Brazil Ministry of Health, health professionals must be vaccinated against the hepatitis B virus (HBV) and provide laboratory proof of immunization. Aims. To evaluate the seroprevalence of HBV infection and to analyze the response to vaccine by measuring serum antibodies against HBV surface antigen (anti-HBs) levels in a sample of students and health professionals at the Federal University of Bahia.Results. As part of this cross-sectional study, a campaign against occupational HB was launched in 2007 and vaccination and blood samples were collected for analysis of the following serological markers: HBV surface antigen (HBsAg) and anti-HBs (measured by enzyme-linked immunoassay) and total antibodies against HBV core antigen (anti-HBc). The study sample comprised 766 people. Global seropositivity for HBV was 1.7%: 0.5% in the students and 8.8% in the professionals. In a group of volunteers, a serological profile compatible with postvaccine immunity was shown by 95% of volunteers with proof of vaccination and by 81.8% of volunteers without proof of vaccination. Conclusions. In conclusion, this study shows that it is important to promote vaccination campaigns and improve knowledge and awareness about HB among health care workers and higher education students.     

Hepatitis A and B vaccination and public health

Summary.  The introduction and implementation of hepatitis B vaccination programmes in areas of high endemicity has been very stressful. However, this initial accomplishment has led to the reassessment of priorities in some countries which could undermine these early successes. Work still remains to be done to support and implement interventions that will bring us closer to the WHO goal and to the control of hepatitis B in the community at large. Hepatitis A vaccine strategy for immunizing toddlers is shifting to those countries with intermediate endemicity where increasing morbidity in adults is being observed. Accumulating evidence indicates that such programmes can result in impressive reductions in the incidence of hepatitis A by herd immunity. Monitoring of these populations to determine durability of protection will be important to avoid shifting the infection to the older age population, when symptoms are more likely to occur. National policies need to consider hepatitis A vaccination in the context of other public health priorities.     

Intradermal hepatitis B vaccination in health care workers. Response rate and experiences from vaccination in clinical practise.

Health care workers at risk for hepatitis B virus infection are recommended for vaccination. Low-dose intradermal (i.d.) administration of vaccine has been suggested as a less expensive alternative to intramuscular (i.m.) inoculation. To evaluate the i.d. vaccination route, health care workers were included in a prospective study. The subjects were vaccinated with 0.1 ml (= 2 microg) recombinant vaccine (Engerix B, SmithKline Beecham) i.d. at 0, 1 and 6 months. Two months after the third vaccination, measurement of the anti-HBs level was conducted. An anti-HBs level > or =10 IU/l was considered protective. Those with an anti-HBs level <10 IU/l were given a fourth dose with new serological control after another 2 months. The results are based on the 1406 subjects that it was possible to evaluate. The seroconversion rate to protective anti-HBs level after 3 doses was 68% and after 3 or 4 doses 89%. Factors associated with a lower response rate were increasing age (p<0.05) and smoking (p<0.001). Sex or body mass index had no influence on the results. Vaccination technique seems to be of utmost importance when the i.d. route is used. Well instructed and experienced nurses are required and quality control with follow-up of overall seroconversion rate within each centre is needed.     

乙型肝炎疫苗免疫

根据2000年世界卫生组织、联合国儿童基金会/艾滋病基金会和美国疾病控制中心报告,死亡率列世界前10位的传染病顺序为:(1)下呼吸道感染;(2)艾滋病;(3)腹泻病;(4)结核病;(5)疟疾;(6)麻疹;(7)乙型肝炎(简称乙肝);(8)百日咳;(9)新生儿破伤风;(10)肠道寄生虫病。全世界约20亿人有现症或既往乙肝病毒     

Hepatitis B vaccination

Alcoholics are at risk to develop hepatitis B infections, chronic active hepatitis, and even hepatoma. Hence, immunization with hepatitis B vaccine is recommended. However, immune abnormalities may coexist which alter their responsiveness to vaccination. This study compares the immune response to this vaccine in controls (group I), alcoholics without overt liver disease (group II), and alcoholics with clinical liver disease (group III). By the seventh month after the initial vaccination, 89% in group I, 70% in group II, and 18% in group III had a response >36 RIA units. The magnitude of the response was significantly different in groups I, II, and III (19,456 vs 8,326 vs 153 RIA units, respectively; P <0.05, group I vs III). In those who did not respond, a significant (P < 0.02) lower helper/inducer (T ₄)class of lymphocytes was observed as compared to patients who exhibited an adequate response. These observations suggest: (1) that the response to hepatitis B vaccine is a T-cell-dependent event and (2) that in this population, using the existing vaccine, postvaccination evaluations of antibody concentrations are needed before protection against hepatitis B infection can be assumed.This research was funded by the Veterans Administration, Cincinnati, Ohio; and Merck, Sharp and Dohme Laboratories.