anti-HBs Antibody Levels Research Articles

Post-Exposure Prophylaxis against HBV and HIV Infection in Health Care Workers

Healthcare Workers (HCWs) are constantly at risk of exposure to viral infections such as hepatitis B virus (HBV), human immune deficiency virus (HIV) and hepatitis C virus (HCV). We aim at demonstrating the results of a three-year period of a surveillance program in Iran with the prospective follow-up of HCWs exposed to blood-borne viruses. HCWs who had experienced an occupational exposure to HBV, HCV or HIV from September 2005 to 2008 were enrolled in the study. Age, gender, route of exposure, type of fluid, type of virus, job, department, working shift, work experience, wearing gloves when exposed, history of HBV vaccination and the serum level of anti HBs antibody were recorded for all participants through an individual interview. Serum samples were taken from both HCWs and the sources of exposure and were tested by enzyme linked immunosorbent assay (ELISA). The data were gathered through questionnaires completed by a nurse under the supervision of a specialist of infectious diseases. In this study, 100 HCWs who were occupationally exposed to HIV, HCV or HBV were included. Most exposures had occurred among nurses (35%), followed by residents (29%), interns (18%), housekeepers (7%), the lab staff (6%), and specialists (5%). Most of the exposures had occurred in emergency (21%) and surgical (20%) wards. The most common route of exposure was percutaneous injuries (77%) and the most common cases had contacted with needles and angiocaths (71.1%) during injection or opening vein routes (21%). Establishing a surveillance system for registering the occurrence of occupational hazardous exposures, performing prophylactic measures and following up the exposed is a necessity in hospitals so that the number of exposures and occupational diseases among the HCWs can be decreased.

Chronic Schistosoma japonicum Infection Reduces Immune Response to Vaccine against Hepatitis B in Mice

BackgroundHepatitis B and schistosomiasis are most prevalent in Africa and Asia, and co-infections of both are frequent in these areas. The immunomodulation reported to be induced by schistosome infections might restrict immune control of hepatitis B virus (HBV) leading to more severe viral infection. Vaccination is the most effective measure to control and prevent HBV infection, but there is evidence for a reduced immune response to the vaccine in patients with chronic schistosomiasis japonica.Methodology/Principal FindingsIn this paper, we demonstrate in a mouse model that a chronic Schistosoma japonicum infection can inhibit the immune response to hepatitis B vaccine (HBV vaccine) and lead to lower production of anti-HBs antibodies, interferon-γ (IFN-γ) and interleukin-2 (IL-2). After deworming with Praziquantel (PZQ), the level of anti-HBs antibodies gradually increased and the Th2-biased profile slowly tapered. At 16 weeks after deworming, the levels of anti-HBs antibodies and Th1/Th2 cytokines returned to the normal levels.Conclusions/SignificanceThe results suggest that the preexisting Th2-dominated immune profile in the host infected with the parasite may down–regulate levels of anti-HBs antibodies and Th1 cytokines. To improve the efficacy of HBV vaccination in schistosome infected humans it may be valuable to treat them with praziquantel (PZQ) some time prior to HBV vaccination.

Revaccination with Fendrix® or HBVaxPro® results in better response rates than does revaccination with three doses of Engerix-B® in previous non-responders

Because non-response (<10IU/l anti-HBs) after revaccination for hepatitis B occurs frequently (50%), this study aimed to provide evidence for a more effective revaccination regimen by comparing four different revaccinations: (1) three revaccinations with Engerix-B® (n=201); (2) one revaccination with Engerix-B® (n=37); (3) one revaccination with HBVaxPro-40® (n=108); (4) one revaccination with Fendrix® (n=39). The level of anti-HBs antibodies was determined with the AXSYM-MEIA system (Abbott, Chicago, USA). Using linear and logistic regression, the efficacy (antibody response) after the four revaccinations was compared. Analyses were corrected for age, sex, primary titre and time lag between last revaccination and the titre measurement. The height of the primary titre independently predicted antibody response. Compared to the revaccination scheme using three Engerix-B® doses, revaccination with a single dose of HBVaxPro-40® or Fendrix® performed significantly better. The use of these highly potent vaccines should be considered when revaccinating hepatitis B vaccine non-responders.

Significant rate of hepatitis B reactivation following kidney transplantation in patients with resolved infection

BackgroundLimited data is available on the risk of hepatitis B virus (HBV) reactivation in patients with resolved infection undergoing kidney transplantation. It is generally thought that this risk is negligible. ObjectivesTo evaluate the incidence of HBV reactivation in such patients, and the potential risk factors for reactivation. Study designRetrospective cohort study including 93 patients transplanted with a kidney between 1995 and 2007 who had evidence of resolved HBV infection (HBsAg negative, anti-HBc positive, anti-HBs positive or negative, and normal liver enzymes). HBV reactivation was defined as HBsAg reversion with HBV DNA>2000IU/mL. ResultsSix patients experienced HBsAg reversion followed by HBV reactivation, 3 within the first post-transplant year. Immunosuppression regimen was similar in patients with and without reactivation. Among patients with reactivation only one was positive for anti-HBs antibodies at time of transplantation; these were progressively lost before reactivation. The odds ratio for reactivation in patients without anti-HBs antibodies at transplantation compared to those with anti-HBs antibodies was 26 (95% CI [2.8–240.5], p=0.0012). In patients with anti-HBs antibody titer above 100IU/L, no reactivation was observed. ConclusionsReactivation rate of resolved hepatitis B is not negligible in patients without anti-HBs antibodies at transplantation. We suggest monitoring of liver tests and HBV serology including HBsAg and anti-HBs antibodies after transplantation as well as vaccination pre- and post-transplantation in all patients, including those with resolved hepatitis B, aiming at maintaining anti-HBs antibody level above 100IU/L.

Comparison of long-term immunogenicity (23 y) of 10 μg and 20 μg doses of hepatitis B vaccine in healthy children

To compare the long-term immunogenicity and seroprotection rates in healthy children following 23 years of vaccination with 10 μg or 20 μg doses of plasma-derived hepatitis B vaccine, we revisited all participants from our previous randomized controlled trial. At year 23, 81 participants were tested for HBV serological markers and HBV-DNA, and a booster dose was given to those with anti-HBs titer < 10 mIU/mL. After eliminating the interference of a Year 11 booster dose and vaccines received outside of the trial, around 50% of participants still maintained anti-HBs titers ≥ 10 mIU/mL in both 10 μg and 20 μg groups (p > 0.05). The peak immune response of vaccination (anti-HBs antibody levels at 12 mo after 1st vaccine dose) and Year 11 anti-HBs levels were significantly associated with Year 23 seroprotection rates. Most of the participants in both groups, regardless of their prior immune status, developed a rapid and robust anamnestic antibody response after the booster dose at year 23. No case of clinically significant HBV infection was observed during the entire study period of 23 y with only one transient HBsAg seroconversion in 10 μg vaccine group. We concluded that seroprotection provided by 10μg or 20 μg doses of hepatitis B vaccine persists for 23 years in more than half of vaccinated individuals in highly HBV-endemic areas, irrespective of 10 μg or 20 μg vaccine doses. Future studies with larger sample sizes comparing long-term efficacy of various doses of plasma-derived and recombinant HBV vaccines are recommended.

Clarification to Long-term anti-HBs antibody persistence and immune memory in children and adolescents who received routine childhood hepatitis B vaccination. Hum Vaccin Immunother 2012; 8:813-8

Purpose: This paper presents data from two studies that evaluated 5-year and 10-year persistence of antibodies against hepatitis B (HBV) surface antigen (anti-HBs) and immune response to an HBV vaccine challenge in children and adolescents who had received three doses of a HBV vaccine in infancy as part of routine clinical practice [NCT00519649/ NCT00984139]. Results: Anti-HBs antibody concentrations ³ 10mIU/ml persisted in 83.3% (95% confidence interval [CI]: 78.5−87.5) and 78.3% (95% CI: 73.1−83.0) of subjects aged 7−8 years and 12−13 years, respectively 5−10 years after infant vaccination. One month post-challenge dose, 98.2% (95% CI: 95.9−99.4) and 93.7% (95% CI: 90.2−96.2) of subjects in the two age groups, respectively had anti-HBs antibody concentrations ³ 100mIU/ml. Overall, 99.6% (95% CI: 98−100) and 97.2% (95% CI: 94.5−98.8) of subjects aged 7−8 years and 12−13 years mounted an anamnestic response to the HBV challenge dose, which was well-tolerated. Methods: Healthy children aged 7−8 years and adolescents aged 12−13 years received three doses of a monovalent pediatric HBV vaccine (10µg of HBsAg) before 18 months of age. Serum samples collected before and one month post-HBV vaccine challenge dose were tested for anti-HBs antibody concentrations. Safety assessments were made for the HBV vaccine challenge dose. Conclusions: A three-dose childhood HBV immunization regimen induced persistence of antibodies against HBV infection for 10 years, up to adolescence. This vaccination regimen also conferred long-term immune memory against HBV as evidenced by the strong anamnestic response to the HBV vaccine challenge, despite waning anti-HBs antibody levels.

Anti-HBs levels among children and adolescents with complete immunization schedule against hepatitis B virus. A cross-sectional study in Blumenau, State of Santa Catarina, Brazil, 2007-2008

Vaccination is the main tool for preventing hepatitis B virus (HBV) infection; however, following the completion of the vaccination series, the concentrations of anti-HBs can decline over the years and reach levels less than 10mIU/mL. The persistence of protection in these individuals is still unknown. The present study aimed to determine the anti-HBs antibody levels among children and adolescents who had received a complete vaccination course for hepatitis B. Antibodies against HBV surface antigen (anti-HBs) were tested in 371 individuals aged 10 to 15 years-old. Volunteers who showed undetectable quantities of anti-HBs accounted for 10.2% of the population studied and 39.9% presented antibody titers of less than 10mIU/mL. Anti-HBs ≥ 10mIU/mL were verified in 49.9%. These results corroborate other studies indicating levels of anti-HBs below 10mIU/mL in vaccinated individuals. Additional studies are required to assess whether this indicates susceptibility to HBV infection and the need and age for booster doses.

A young child with Hyper IgE Syndrome (HIES) with a Novel Variant in signal transduction and activator of transcription 3 (STAT3) and Disseminated Histoplasmosis

FEBRUARY 2011 AB18 Abstracts S A T U R D A Y 54 Glycine and L-proline Demonstrate Similar IgG Stabilization in Liquid Immunoglobulin Intravenous 10% (IGIV) Formulations A. K. Sun, Y. Wu, G. Pot, E. Vandamme, W. J. Grossman, T. Wolfgang, H. P. Schwarz; Baxter BioScience, Los Angeles, CA, Baxter BioScience, Westlake Village, CA, Baxter BioScience, Lessines, BELGIUM, Baxter BioScience, Deerfield, IL, Baxter BioScience, Vienna, AUSTRIA. RATIONALE: This study compares the stability at 258C of immunoglobulin intravenous 10% solutions formulated in either 0.25M glycine or 0.25M L-proline at a target pH of 4.8. Both amino acids are used in commercially available IGIVs as excipient, merely to prevent IgG aggregation and fragmentation, which may affect product tolerability. METHODS: Three lots of IGIV process intermediates were divided into two parts and further processed to the final IGIV 10% formulated either in 0.25M glycine or 0.25M L-proline. Products were stored at 25C/60% relative humidity for 6 months. Immunoglobulin monomers, dimers, aggregates and fragments were measured by high-performance size-exclusion chromatography, anti-Hepatitis B surface (anti-HBs) antigen antibodies by an enzyme immunoassay. The data were analyzed using the ‘‘paired t-test’’. RESULTS: There were no statistical significant differences in total ‘‘monomers+dimers’’ (99.1% vs. 99.0%, p50.568), in aggregates (0.12% vs. 0.14%, p50.08), in fragment content (0.74% vs. 0.85%, p50.506) and in the protective anti-HBs antigen antibody level (4.41 IU/mL vs. 4.51 IU/mL, p50.441) between the formulations in glycine and L-proline after 6 months storage. Dimer level was found to be in both formulations well below 10% (6.92% in glycine, 5.10% in L-proline), considered to be the upper limit for good tolerability. CONCLUSIONS: The results obtained from IGIVs formulated in 0.25M glycine or 0.25M L-proline after 6 months storage at 258C indicate that both amino acids provide a similar stabilization of the IgG molecule in liquid formulations at low pH.

Vaccination with a fusion DNA vaccine encoding hepatitis B surface antigen fused to the extracellular domain of CTLA4 enhances HBV-specific immune responses in mice: Implication of its potential use as a therapeutic vaccine

Fusion of specific antigens to extracellular domain of cytotoxic-T-lymphocyte-associated antigen 4 (CTLA4) represents a promising approach to increase the immunogenicity of DNA vaccines. We evaluated this interesting approach for its enhancement on HBV-specific immune responses and its antiviral effects in HBV transgenic mice. A fusion plasmid encoding the extracellular domain of CTLA4 linked with HBsAg was constructed. Mice were immunized by this fusion plasmid. Vaccination with the CTLA4-fused DNA not only induced much higher level of anti-HBs antibody, but also increased HBsAg-specific CD8+ response as well as CTL response in BALB/c mice. Furthermore, both Th1 and Th2 responses were augmented. In HBV transgenic mice, the levels of circulating HBsAg and HBV DNA replication were down-regulated by induction of higher anti-HBs antibody and HBsAg-specific CD8+ response after vaccination with the fusion plasmid. Thus, the CTLA4-fused DNA vaccine led to breakdown of immune tolerance to viral infection in HBV transgenic mice, which might be used as a therapeutic vaccine in HBV infection.

Immunomodulatory activity of andrographolide on macrophage activation and specific antibody response

To investigate the immunomodulatory effects of andrographolide on both innate and adaptive immune responses. Andrographolide (10 microg/mL in vitro or 1 mg/kg in vivo) was used to modulate LPS-induced classical activated (M1) or IL-4-induced alternative activated (M2) macrophages in vitro and humor immune response to HBsAg in vivo. Cytokine gene expression profile (M1 vs M2) was measured by real-time PCR, IL-12/IL-10 level was detected by ELISA, and surface antigen expression was evaluated by flow cytometry, whereas phosphorylation level of ERK 1/2 and AKT was determined by Western blot. The level of anti-HBs antibodies in HBsAg immunized mice was detected by ELISA, and the number of HBsAg specific IL-4-producing splenocyte was enumerated by ELISPOT. Andrographolide treatment in vitro attenuated either LPS or IL-4 induced macrophage activation, inhibited both M1 and M2 cytokines expression and decreased IL-12/IL-10 ratio (the ratio of M1/M2 polarization). Andrographolide down-regulated the expression of mannose receptor (CD206) in IL-4 induced macrophages and major histocompability complex/costimulatory molecules (MHC I, CD40, CD80, CD86) in LPS-induced macrophages. Correspondingly, anti-HBs antibody production and the number of IL-4-producing splenocytes were reduced by in vivo administration of andrographolide. Reduced phosphorylation levels of ERK1/2 and AKT were observed in macrophages treated with andrographolide. Andrographolide can modulate the innate and adaptive immune responses by regulating macrophage phenotypic polarization and Ag-specific antibody production. MAPK and PI3K signaling pathways may participate in the mechanisms of andrographolide regulating macrophage activation and polarization.

Persistence of vaccine immunity against hepatitis B virus and response to revaccination in vertically HIV-infected adolescents on HAART

Humoral immune response to vaccine antigens is known to be reduced in perinatally HIV-infected children. Lymphocyte immunophenotyping, humoral immunity to hepatitis B after primary immunization and response to revaccination were evaluated in 40 HIV-infected adolescents on HAART and 23 healthy age-matched controls. Anti-HBs antibody levels ≥10mIU/mL were found in 18/40 (40.5%) of the HIV-infected adolescents and 18/23 (78.3%) of the HIV-negative adolescents from Control group. Adolescents of HIV group with anti-HBs≥10mIU/mL presented a higher CD4+ T cell percentage, higher naïve and central memory CD8+ T cell percentages and lower immune activation markers. After revaccination, 12/18 (66.7%) adolescents of HIV group responded. Those adolescents who did not respond to revaccination presented a lower CD4+ T cell percentage, higher immune activation markers and more frequently detectable HIV viral load. We concluded that lower immune activation, higher CD4+ T cell percentage and better control of HIV replication may be associated with hepatitis B vaccine response.

Comparative evaluation of the immunogenicity of combined hepatitis A and B vaccine by a prospective and retrospective trial

In the past, immunogenicity of hepatitis A and B vaccines needed to be questioned in persons of advanced age, especially in those of 40 years and older.We performed a comparative multicenter prospective and retrospective study with the combined hepatitis A and B vaccine Twinrix® to identify factors influencing the results of the vaccination in a population of all age groups.Out of 489 subjects enrolled, 241 were vaccinated in a prospective study (group 1) and 248 subjects in a retrospective study (group 2) in 17 German centers with median age of 40.1 (14-79) years. Following three applications of the combined hepatitis A/B vaccine we found 96.2% with protective antibodies against HAV and 88.7% were protected against HBV.With increasing age the subjects developed decreasing anti-HBs antibody levels whereas the seroprotection rate was significantly reduced by age (p

Investigation (In Vivo and In Vitro) of Booster Dose Vaccine Requirement for Long-Term Protection against Hepatitis B Virus Infection

Aim: Studies have shown that no booster dose was required at least 10 to 15 years after a primary vaccination for individuals who developed protective anti-hepatitis B surface (anti-HBs) antibodies. In this study, booster dose requirement for HBV after primary immunization was investigated. Materials and Methods: Seventeen individuals vaccinated previously were enrolled in the study. They had once developed a protective level of anti-HBs antibody after immunization and their anti-HBs titer had declined to an underprotective level. Twenty uninfected and unvaccinated healthy people were chosen as controls. Lymphoproliferative response to in-vitro stimulation with hepatitis B surface antigen (HBsAg) and anti-HBs response to vaccine were evaluated for immune response. Results: T lymphocytes from 4 (24%) of the study group showed lymphoproliferative response to HBsAg stimulation while none of the controls did (P < 0.05). In all subjects in the study group, anti-HBs response (>= 10 mIU/ml) was detected 1 to 7 days after the booster injection but in only 2 of the controls antibody response was detected 28 days after the first dose of HBV vaccine (P < 0.0001). Conclusions: A booster dose of HBV vaccine might not be required because of immunological memory.

Prevention of Vertical Hepatitis B Transmission by Hepatitis B Immunoglobulin in the Third Trimester of Pregnancy

Passive-active immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine provides a high level of protection against vertical transmission of hepatitis B virus (HBV). Nevertheless, 1 in 10 children of HBV carriers have chronic hepatitis B early in their lives despite immunoprophylaxis because they were infected in utero. This study of 469 pregnant women testing positive for hepatitis B surface antigen (HbsAg) was conducted to learn whether giving HBIG to HBV carriers in the third trimester can prevent vertical transmission of the virus. Of the women entered into the study, all of whom were asymptomatic, 126 (group 1) tested positive for hepatitis B e antigen (HbeAg), while 343 (group 2) did not. HBIG was given intramuscularly in a dose of 200 IU at 28, 32, and 36 weeks of pregnancy. All newborn infants received 100 IU of HBIG within 12 hours of birth as well as the first of 3 doses of hepatitis B vaccine (the subsequent doses were given at ages 1 and 6 months). In group 1, 16% of infants whose mothers received HBIG in the third trimester tested positive for HbsAg at birth and 7% at age 6 months. The respective figures for infants whose mothers were not treated were significantly higher at 39% and 23%. No such treatment-related difference was observed in group 2 infants. At age 6 months, rates of protective levels of anti-Hbs antibody were 32% in group 1 infants whose mothers were HbeAg-positive and 56% in group 2 infants when the mothers had not received HBIG while pregnant. The respective figures for infants whose mothers were treated in the third trimester were 76% and 89%. Neither mothers nor their infants experienced adverse effects related to the administration of HBIG or hepatitis B vaccine. The investigators conclude that, if all HbsAg-positive pregnant women, regardless of HbeAg status, were to receive HBIG in the last weeks of pregnancy, their infants would be better protected against chronic HBV infection.

Intestinal helminthes and/or Toxocara infection are unrelated to anti-HBs titers in seven-year-old children vaccinated at birth with recombinant hepatitis B vaccine

The aim of this investigation was to evaluate the possible effect of nematode infection on anti-HBs antibody levels in the serum of seven-year-old schoolchildren vaccinated at birth with the recombinant hepatitis B vaccine. Anti-HBs and anti HBc antibodies were evaluated in the sera of 100 schoolchildren with at least one intestinal nematode and/or a positive serological reaction for anti-Toxocara antibodies and in 95 schoolchildren without intestinal helminthiasis or serum anti-Toxocara antibodies. Both groups were from public elementary schools located on the urban periphery of Vitória, ES, Brazil. Among these 195 children, the median anti-HBs antibody titer was 31.3 IU/ml and the frequency of titers less than 10 IU/ml was 33.8% (95% CI: 27.1-40.4%). There were no significant differences between the medians of anti-HBs titers or the frequency of titers less than 10 IU/ml between the groups with or without helminthes (29.5 and 32.9 IU/ml and 33 and 34.7%, respectively; p>0.05). Even when the children with intestinal nematodes and/or anti-Toxocara antibodies and with blood eosinophil counts over 600/mm(3) were compared with children without infection from intestinal nematodes and without anti-Toxocara antibodies, with blood eosinophil counts less than 400 eosinophils/mm(3), these differences were not significant. None of the children presented anti-HBc antibodies. In conclusion, infections with intestinal nematodes and/or the presence of anti-Toxocara antibodies did not interfere with the anti-HBs antibody titers in seven-year-old children vaccinated at birth with the recombinant hepatitis B vaccine.

Evoluation of HBV Antibodies Evoked by Immunization And Infection Among Health Employee and Population

In present study HBV-markers (HBs Ag and Anti HBs) were investigated in two different groups. HBV antibodies evoked by immunization and infection in health employees and population were researched and compared each other. From January 1998 to January 2000 we investigated hepatitis B virus markers (HBS Ag and Anti HBs) by ELISA technique (Bioelisa, Biokit S.A., Spain) in total of 248 persons, 100 from normal population and 148 from healthy hospital employees. Following detection of HBV markers, HBV vaccine (GenHevac B, Pasteur) was administered in 96 subjects with being seronegative of HBs Ag and Anti HBs. Serum samples were collected on the 30th days of postvaccination for Anti HBs response. In the group of healthy hospital employees, the frequency of positivity for HBs Ag and Anti HBs antibodies was 35.14 % (52 of 148) and 5.41 % (8 of 148) respectively. At the same time HBs Ag and Anti HBs positivity were 5 % (5 of 100) and 26 % (26 of 100) in healthy population. There weren't any immunization occur after the first dose of vaccination. One month after the second dose, 3 subjects of hospital employees and one subject of healthy population and one month after the third dose, almost all subjects (except one in hospital employees) were being seroprotected. Hepatitis B virus is a common viral agent; so vaccination has been seemed to be necessary in order to eradicate Hepatitis B infection. The vaccine should be applied at high risk groups especially in health workers before beginning working. In this study it has been shown that the first and second dose of vaccine were insufficient in developing Anti HBs antibodies. In conclusion three doses immunization course against HBV were necessary to elicit protective levels of Anti HBs antibodies.

Dynamics of a hepatitis B virus e antigen minus population ascribed to genotype F during the course of a chronic infection despite the presence of anti-HBs antibodies

The in vivo evolution of genotype F HBV variants was recorded in a chronically infected patient throughout a 3-year observation period. Fluctuating levels of HBs Ag and anti-HBs antibodies were recorded, both of them cocirculating in peripheral blood samples at given times. Fifty S gene derived clones were sequenced and phylogenetically analyzed. As expected, some amino acid replacements within the S ORF were also observed within the P ORF while others were silent for the former. Such change was statistically significant for both S and P overlapping genes, which clearly indicates the appearance of a positive selection pressure. Supporting this notion, amino acid replacements were documented at both B and T cell epitopes in samples from 1997 and 1998. Several mutations were documented within and outside the “ a” determinant in the major hydrophilic region. Such substitutions might have resulted from the attempt of HBV to evade both humoral and/or cellular immune response. To the best of our knowledge this unusual profile of HBV variants in presence of usually “neutralizing” anti-HBs antibodies was examined in vivo for the first time.

Comparison of Two Hepatitis B Vaccines (GeneVac-B and Engerix-B) in Healthy Infants in India

Hepatitis B is a major problem in many parts of the world. The WHO has recommended the inclusion of hepatitis B vaccines in routine immunization schedules. We wanted to compare two recombinant hepatitis B vaccines in an infant population for immunogenicity and reactogenicity when given at 6, 10, and 14 weeks of age. One hundred seventy-three infants meeting eligibility criteria were given either GeneVac-B (Serum Institute of India Ltd.) or Engerix-B (GlaxoSmithKline Beecham) in a random fashion. Three 0.5-ml (10-mug) doses of the vaccines were given at 6, 10, and 14 weeks of age along with diphtheria-pertussis (whole cell)-tetanus (DTPw) vaccine. Blood samples were collected at baseline and 1 month after administration of the third dose of the vaccines to measure anti-HBs antibody levels. Seroconversion was defined as a titer of more than 1 x 10(-3) IU/ml, while seroprotection was defined as a titer of more than 10 x 10(-3) IU/ml. Of the GeneVac-B recipients, 98% seroconverted versus 99% of the Engerix-B group. The anti-HBs geometric mean titer was slightly greater for GeneVac-B (229 x 10(-3) IU/ml) than for Engerix-B (167 x 10(-3) IU/ml), but the difference was not significant. The seroprotection rates were similar for both vaccines (96% and 95%, respectively). The most common systemic reaction events were mild to moderate fever, excessive crying, local swelling, rash, and irritability, and the local reactions were redness, induration, and edema, which most probably were caused by the simultaneously administered DTPw vaccine. All events were transient and resolved without sequelae. Reactogenicity was similar for the two vaccines. The present study shows that GeneVac-B is as immunogenic and as well tolerated as Engerix-B when administered with DTPw vaccine at 6, 10, and 14 weeks of age.

O.116 Reasons for the lack of anti-HBC antibody detection in hepatitis B virus chronically infected patients

Hepatitis B virus (HBV) testing of blood donors in India is focused on the presence of HBsAg. However, the absence of HBsAg in the blood of the healthy individual may not be sufficient to ensure lack of circulating HBV.The aim of this study is to estimate the prevalence of anti HBc and anti HBs pattern in anti HBc reactive but HBsAg negative blood donors.6134 Blood donor samples were tested prospectively from 16th April to 7th July, 2007 for HbsAg and anti HBc (IgM + IgG) antibodies using BIORAD MONOLISA HbsAg ULTRA and BIO-RAD MONOLISA anti-HBc PLUS test kits. All the samples, which were negative for HbsAg but reactive for anti HBc, were tested for anti-HBs antibodies Using BIO-RAD MONOLISA ANTI HBs 3.0 test kits.Out of 6134 donor samples tested, 63 samples were HbsAg positive (1.02 %) and 499 samples (8.13%) showed anti HBc reactivity but HbsAg negative.195 (39.07%) out of 499 anti HBc positive samples showed levels of anti HBs above 15 IU/ml and 304 (60.92 %) showed levels of anti HBs below 15 IU/mL. The samples showing values above 15 IU/mL are considered positive and samples below 15 IU/mL are considered negative as per BIO-RAD MONOLISA anti HBs 3.0 instruction manual.The data indicates that high percentage of blood donors (60.92%) were anti-HBc reactive and have low levels of preventive anti HBs antibodies. Accordingly all blood donor samples should be tested routinely for anti HBc and if the sera are reactive, regardless of anti-HBs titer, the blood should be discarded. Further testing for HBV-DNA is appropriate to follow up the blood donor for HBV infection.

Compliance to hepatitis B vaccination and subsequent development of seroprotection among health care workers of a tertiary care center of Saudi Arabia

There is lack of reliable data on compliance to hepatitis B virus (HBV) vaccine and development of seroprotective levels of antibodies among health care workers (HCWs) from the countries with high HBV endemicity such as Saudi Arabia. This study aimed to assess the compliance with HBV vaccine and subsequent levels of seroprotection among HCWs of a large tertiary care center of the Eastern Province of Saudi Arabia. All the HCWs (n = 1302) involved in direct patient care, including 374 (28.7%) physicians, 619 (47.6%) nurses, and 309 (23.7%) technicians, were enrolled for the study. Those having antibody to hepatitis B surface antigens (anti-HBs) levels less than 10 mIU/mL were advised to take 3 doses of yeast-derived recombinant HBV vaccine at 0, 1, and 6 months of 1 mL (20 microg/mL) in the deltoid muscle. Blood samples were checked for anti-HBs antibody levels by enzyme immunoassay during the initial screening of HCWs and 3 months after the third dose of HBV vaccine. The group of physicians included 34.5% (129/374) of consultants, 16.8% (63/374) of specialists, and 48.6% (182/374) of residents. An overall HBV vaccine compliance rate of 71.6% (932/1302) was observed among HCWs including that of 79.5% (492/619) among nurses, 78.3% (242/309) among technicians, and 52.9% (198/374) among physicians. Thus, physicians recorded the lowest compliance (OR, 3.211; 95% CI, 2.259-4.567; P < .0001) to HBV vaccine. Among physicians, the lowest compliance of 42.3% (77/182) was observed in residents (OR, 3.690; 95% CI, 1.067-3.703; P < .0001). The overall seroprotection after vaccination was achieved in 92.2% of the compliant HCWs, and 7.8% of them failed to mount adequate response to HBV vaccine. Nonresponders included mainly the physicians (OR, 2.229; P = .05)-consultants in particular (OR, 3.476; P < .0001). The mean age of nonresponders was higher than those who mounted an adequate anti-HBs response (46.7 +/- 6.3 vs. 32.2 +/- 3.3 years OR, 1.845; 95% CI, 0.999-3.414; P < .05). Poor compliance to HBV vaccine among physicians--residents in particular-is an issue of immense concern, which demands close examination and identification of the specific action that needs to be taken to enhance the uptake of the vaccine by this target population.