Prevention of hepatitis B in nonresponders to initial hepatitis B virus vaccination

Attractive and healthy-looking male faces do not show higher immunoreactivity

Previous research has indicated that facial attractiveness may provide cues to the functioning of the immune system. Mating with individuals who have a more effective immune system could lead to a higher reproductive success. Our main aim was to test a possible association between immunoreactivity (stimulated by vaccination) and perceived facial attractiveness and healthiness. We experimentally activated the immune system of healthy men using vaccination against hepatitis A/B and meningococcus and measured levels of specific antibodies (markers of immune system reactivity) before and 30 days after the vaccination. Further, 1 day before the vaccination, we collected their facial photographs that were judged by females for attractiveness, healthiness, and facial skin patches for healthiness. In view of its proposed connection with the functioning of the immune system, we also measured skin colouration (both from the facial photographs and in vivo using a spectrophotometer) and we assessed its role in attractiveness and healthiness judgements. Moreover, we measured the levels of steroid hormones (testosterone and cortisol) and the percentage of adipose tissue, because both are known to have immunomodulatory properties and are related to perceived facial attractiveness and healthiness. We found no significant associations between antibody levels induced by vaccination and perceived facial attractiveness, facial healthiness, or skin healthiness. We also found no significant connections between steroid hormone levels, the amount of adipose tissue, rated characteristics, and antibody levels, except for a small negative effect of cortisol levels on perceived facial healthiness. Higher forehead redness was perceived as less attractive and less healthy and higher cheek patch redness was perceived as less healthy, but no significant association was found between antibody levels and facial colouration. Overall, our results suggest that perceived facial attractiveness, healthiness, and skin patch healthiness provide limited cues to immunoreactivity, and perceived characteristics seem to be related only to cortisol levels and facial colouration.

Signaling differences in peripheral blood mononuclear cells of high and low vaccine responders prior to, and following, vaccination in piglets

Individual variability in responses to vaccination can result in vaccinated subjects failing to develop a protective immune response. Vaccine non-responders can remain susceptible to infection and may compromise efforts to achieve herd immunity. Biomarkers of vaccine unresponsiveness could aid vaccine research and development as well as strategically improve vaccine administration programs. We previously vaccinated piglets (n = 117) against a commercial Mycoplasma hyopneumoniae vaccine (RespiSure-One) and observed in low vaccine responder piglets, as defined by serum IgG antibody titers, differential phosphorylation of peptides involved in pro-inflammatory cytokine signaling within peripheral blood mononuclear cells (PBMCs) prior to vaccination, elevated plasma interferon-gamma concentrations, and lower birth weight compared to high vaccine responder piglets. In the current study, we use kinome analysis to investigate signaling events within PBMCs collected from the same high and low vaccine responders at 2 and 6 days post-vaccination. Furthermore, we evaluate the use of inflammatory plasma cytokines, birthweight, and signaling events as biomarkers of vaccine unresponsiveness in a validation cohort of high and low vaccine responders. Differential phosphorylation events (FDR < 0.05) within PBMCs are established between high and low responders at the time of vaccination and at six days post-vaccination. A subset of these phosphorylation events were determined to be consistently differentially phosphorylated (p < 0.05) in the validation cohort of high and low vaccine responders. In contrast, there were no differences in birth weight (p > 0.5) and plasma IFNγ concentrations at the time of vaccination (p > 0.6) between high and low responders within the validation cohort. The results in this study suggest, at least within this study population, phosphorylation biomarkers are more robust predictors of vaccine responsiveness than other physiological markers.

Evaluation of Anti-HBsAg Titres among the High-Risk Population of A Tertiary Care Hospital, Tamil Nadu, India

Health care workers (HCW) are a high-risk population for Hepatitis B infection. Hepatitis B vaccine which is 95% effective confers long-term protection and anti-HBs titre is a marker for protective immune response. Our objective was to assess the status of hepatitis B vaccination and to evaluate the anti-HBsAg titres among health care workers in a tertiary care hospital, Tamil Nadu. It was an observational study conducted among 610 Health care workers in a tertiary care teaching hospital from June to December 2018 after obtaining clearance from IEC. Workers were assessed for their HBV vaccination status and for their anti-HBsAg titre after getting informed consent. The antibody titres were measured using CLIA (chemiluminescent Immunoassay) supplied by Abbott diagnostics. The data was entered and analyzed using a Microsoft Excel sheet. In our study, 80.5% were fully vaccinated, 18.5% of them were defaulters which comprised the HCW with 2 doses and 1 dose of vaccine and 0.9% were not vaccinated. In the fully vaccinated group, 37% showed Anti HBs titres of 10-100 mIU/ml, 59.2% showed the titre of > 100 mIU/ml and 3.6% did not show the protective antibody titre (<10 mIU/ml ). The 3.6% who did not show protective antibody titre were given the booster dose of vaccine. Among those who received a booster dose, 61.1% responded with the titre of 10-100 mIU/ml and 22.2% responded with the titre of > 100 mIU/ ml and 16.6% did not respond even with the booster dose. In the defaulters 86.7% had titres < 10 mIU/ml , 9.7% had titres of 10 mIU/ml and 3.6% had titres > 10 mIU/ml. In the non vaccinated group all had titres < 10 mIU/ml. The present study emphasizes the importance of screening of anti-HBsAg titres to be made mandatory for all the health care workers along with HBV Vaccination.

No evidence for association between human body odor quality and immune system functioning

Previous studies have shown that women perceive male faces with a more reactive immune system as more attractive, but whether body odor might likewise provide cues to immune function has not been investigated yet. These two studies tested a possible relationship between body odor quality and immunoreactivity (Study 1) and immune system function (Study 2). In Study 1, we collected body odor samples from 21 men just before and two weeks after vaccination against hepatitis A/B and meningococcus. We determined the levels of specific antibodies (selected as markers of immune system's reactivity), testosterone, and cortisol. Subsequently, 88 female raters assessed the odor samples for their attractiveness, intensity, and healthiness. In Study 2, we collected body odor and blood samples from 35 men and women. We assessed key parameters of their innate and adaptive immunity, such as complement activity or total lymphocyte T and B counts and asked 95 raters to assess the odor samples for their attractiveness, intensity, and healthiness. In Study 1, we found no significant association between antibody levels induced by vaccination and perceived body odor attractiveness, intensity, and healthiness. We also found no significant relationship between antibody levels and steroid hormones (testosterone and cortisol). In Study 2, we likewise found no association between basal key parameters (innate and adaptive) of the immune system and body odor quality. Our results indicate that body odor may not serve as a cue to the reactivity of the immune system.

CpG-Adjuvanted Hepatitis B Vaccine (HEPLISAV-B®) Update

Introduction: HEPLISAV-B is a hepatitis B vaccine composed of rHBsAg mixed with a synthetic oligonucleotide containing CpG motifs that stimulate innate immunity through TLR9. This vaccine was recently approved by FDA in view of its superior efficacy.Areas covered: Published literature on HEPLISAV-B was critically reviewed. Four randomized controlled trials among 7,056 subjects receiving 2 doses of HEPLISAV-B and 3,214 subjects receiving 3 doses of Engerix-B showed superior seroprotection rate (SPR) (anti-HBs ≥10 mIU/mL) of 90-100%, compared with 71-90% in those receiving Engerix-B. Furthermore, the seroprotection rate was also significantly higher in HEPLISAV-B compared with Engerix-B recipients in persons with traditionally poor vaccine responses such as older adults, diabetics, and those with chronic kidney disease. The safety profiles among 9,871 subjects were similar between HEPLISAV-B and Engerix-B .Expert opinion: HEPLISAV-B, a CpG adjuvant mixed with HBsAg, is more efficacious and produced earlier seroprotection compared to existing vaccines, with a favorable safety profile. The shorter, two-dose regimen, earlier seroprotection, higher adherence, and a higher seroprotection rate, especially in populations with traditionally poor vaccine response, makes this an important therapeutic option in hepatitis B vaccination.

Characterization of hepatitis B virus surface antigen particles expressed in stably transformed mammalian cell lines containing the large, middle and small surface protein

Vaccination still represents the most efficient and inexpensive strategy in the control of hepatitis B virus (HBV) infection. However, about 10% of the population vaccinated with the current yeast derived vaccine, consisting of the non-glycosylated form of the small envelope protein (S) of the HBV, fail to display an adequate immune response. Therefore, there is a need for the development of new vaccines with enhanced immunogenicity. On this regard, new generation vaccines containing L and preS2-containing HBV surface proteins in addition to S, have proven to be able to bypass the lack of response of the standard vaccine. In this work, we describe the development of stable recombinant CHO-K1 and HEK293 cell lines able to produce and secrete hepatitis B subviral envelope particles (HBV-SVPs) composed by the three surface proteins of the HBV. In turn, we demonstrated that these particles induced a specific humoral immune response in experimental animals and triggered the production of antibodies with the ability to recognize the binding site of HBV with the hepatocyte. Thus, these HBV-SVPs represent a promising candidate as a new generation vaccine in order to enhance the immunogenicity of the conventional yeast derived HBV vaccine.

Analysis of antibody-negative medical students after hepatitis B vaccination in Japan

Hepatitis B virus (HBV) vaccination is recommended for health-care professionals because of their frequent contact with blood. At one medical school, new students undergo HBV antibody tests upon admission, and antibody-negative individuals receive the HBV vaccine. We aimed to characterize individuals who remained antibody negative after HBV vaccination. Between 2009 and 2017, we enrolled 1064 first-year students from a medical school where their HBV antibody test and vaccination records remained. We analyzed data regarding the hepatitis B surface antibody (anti-HBs) test record during admission, vaccination record for antibody-negative participants, anti-HBs test result after completing the three vaccination doses, drug name of the vaccine used, sex, body mass index (BMI), and age. We calculated the yearly percentage of antibody-negative individuals and analyzed the characteristics of vaccine-refractory cases by logistic regression analysis. Of the 1064 participants, 999 were initially antibody negative. They were vaccinated with HBV thrice and tested for antibodies after vaccination. The average age of participants was 20.1 y, with 677 males. Although the type of vaccine has been changed since 2016, the average rate of refractoriness from 2009 to 2015 was 6.9% per year and 18.6% after 2016. Logistic regression analyses showed that sex (male vs. female; OR, 1.787), BMI (OR. 1.171), and vaccine type (genotype A vs. genotype C: OR, 3.144) were significant factors associated with antibody-negative individuals. Vaccine type differences altered the proportion of antibody-refractory individuals, with no association with age. The data on vaccine refractoriness will be continuously analyzed in the future while considering other factors.

Age-related immunogenicity and reactogenicity of live oral cholera vaccine CVD 103-HgR in a randomized, controlled clinical trial

Aging is accompanied by a decline in immune function which can lead to decreased responses to vaccines. Attenuated recombinant Vibrio cholerae O1 vaccine strain CVD 103-HgR elicits a rapid serum vibriocidal antibody (SVA) response and protects against cholera diarrhea in volunteer challenge studies but has not been studied in older adults. We evaluated CVD 103-HgR (PXVX0200) in adults age 46-64, compared them to previously studied adults age 18-45, and studied age-related immunogenicity across adults 18-64 years of age. Volunteers were randomized to receive a single dose of 1 × 10⁹ CFU of PXVX0200 or placebo. Immunogenicity endpoints included SVA and anti-cholera toxin (CT) antibody levels on days 1, 11, 29, 91 and 181 and lipopolysaccharide (LPS) and CT-specific IgA and IgG memory B cells on days 1, 91 and 181. Safety was assessed by comparing solicited signs and symptoms on days 1-8 and other adverse events through day 181. 2979 volunteers received vaccine, including 291 age 45-64. Day 11 seroconversion occurred in 90.4% of older adults vs 93.5%% of younger adults and met the endpoint of demonstrating non-inferiority between the two groups. Significant increases in LPS-specific IgG and IgA and CT-specific memory IgG memory B cells were seen at days 91 and 181. There appeared to be a continuous age-related decline in SVA seroconversion and geometric mean titers, but not memory B cell responses, across the 18-64 year age range. Most reactogenicity was mild and was more common in the placebo group. PXVX0200 appears safe and immunogenic in older adults. Clinical Trials Registration: clinicaltrials.gov NCT02100631.

Humoral and cell-mediated immune responses after a booster dose of HBV vaccine in HIV-infected children, adolescents and young adults

OBJECTIVE

HBV vaccine induces protective antibodies only in 23-56% of HIV-infected children. The aim of our study is to evaluate the immunologic effects of a booster dose of HBV vaccine in HIV-infected youth.

DESIGN

53 young HIV-infected patients in whom HBV vaccination did not elicit protective Ab titers were enrolled. All patients were on ART with optimal immunological and viral response.

METHOD

All patients received a booster dose of HBV vaccine (HBVAXPRO 10 μg i.m.). HBV-specific Ab titer, viral load and CD4+ T cells were measured at baseline (T0), T1, T6 and T12 months. In a subgroup of 16 patients HBV-specific cell mediated immune responses were evaluated at baseline, at T1 and T6.

RESULTS

The booster dose induced seroconversion in 51% of patients at T1, 57% at T6, and49% at T12; seroconversion rate was significantly correlated with CD4+T cells at T0 and to the CD4 nadir. The booster dose induced HBV-specific cell mediated immunity at T6 mainly in Responders (Rs): Effector Memory CD8+T cells, HBV-specific TNFα-, IFNγ-, granzyme secreting CD8+ T cells and IL2-secreting CD4+ T cells were significantly increased in Rs compared to T0. In Non Responders (NRs), HBV-specific IL2-secreting CD4+ T cells, Central and Effector Memory CD8+ T cells were the only parameters modified at T6.

CONCLUSIONS

Seroconversion induced by a booster dose of vaccine correlates with the development of T cell immunological memory in HIV-infected patients who did not respond to the standard immunization. Alternate immunization schedules need to be considered in NRs.

The role of nanotechnology in the treatment of viral infections

Infectious diseases are the leading cause of mortality worldwide, with viruses in particular making global impact on healthcare and socioeconomic development. In addition, the rapid development of drug resistance to currently available therapies and adverse side effects due to prolonged use is a serious public health concern. The development of novel treatment strategies is therefore required. The interaction of nanostructures with microorganisms is fast-revolutionizing the biomedical field by offering advantages in both diagnostic and therapeutic applications. Nanoparticles offer unique physical properties that have associated benefits for drug delivery. These are predominantly due to the particle size (which affects bioavailability and circulation time), large surface area to volume ratio (enhanced solubility compared to larger particles), tunable surface charge of the particle with the possibility of encapsulation, and large drug payloads that can be accommodated. These properties, which are unlike bulk materials of the same compositions, make nanoparticulate drug delivery systems ideal candidates to explore in order to achieve and/or improve therapeutic effects. This review presents a broad overview of the application of nanosized materials for the treatment of common viral infections.

Research progress of therapeutic vaccines for treating chronic hepatitis B

Hepatitis B virus (HBV) is a member of Hepadnavirus family, which leads to chronic infection in around 5% of patients with a high risk of developing liver cirrhosis, liver failure, and hepatocellular carcinoma. ¹ Despite the availability of prophylactic vaccines against hepatitis B for over 3 decades, there are still more than 2 billion people have been infected and 240 million of them were chronic. Antiviral therapies currently used in the treatment of CHB (chronic hepatitis B) infection include peg-interferon, standard α-interferon and nucleos/tide analogs (NAs), but none of them can provide sustained control of viral replication. As an alternative strategy, therapeutic vaccines for CHB patients have been widely studied and showed some promising efficacies in dozens of preclinical and clinical trials. In this article, we review current research progress in several types of therapeutic vaccines for CHB treatment, including protein-based vaccines, DNA-based vaccines, live vector-based vaccines, peptide-based vaccines and cell-based therapies. These researches may provide some clues for developing new treatments in CHB infection.

Vaccination against hepatitis B virus among people who inject drugs - A 20year experience from a Swedish needle exchange program

BACKGROUND

People who inject drugs (PWID) are at particular risk of hepatitis B virus (HBV) acquisition, but often have poor access or adherence to HBV vaccination. Vaccination against HBV has been offered at a major Swedish needle exchange program (NEP) since 1994. The aim of this study was to evaluate vaccine completion and response rates, and the effect of sequential booster doses to non-responders to the standard vaccination schedule.

METHODS

PWID enrolled in the NEP 1994-2013, without serological markers for HBV at baseline (negative for HBsAg/anti-HBc/anti-HBs), were offered a three-dose standard intramuscular vaccination schedule (Engerix®-B, GSK, 20μg/mL, intended to be received at months 0, 1 and 6). Vaccination response was defined as protective levels of anti-HBs (⩾10mIU/mL). Up to three booster doses were then offered for non-responders, each followed by anti-HBs testing.

RESULTS

HBV data was available for 2352 identifiable individuals at NEP enrolment, of whom 1516 (64.5%) had no markers for previous HBV exposure or vaccination. Vaccination was initiated for 1142 (75.3%) individuals and 898 (59.2%) completed the standard vaccination schedule. Post-vaccination anti-HBs levels were available from 800 individuals, with 598 (74.8%) responding to the basic vaccination schedule. After up to three booster doses a total of 676 (84.5%) individuals achieved protective anti-HBs levels. Non-response to vaccination was associated with higher age and anti-HCV positivity (p<0.001). Eighteen incident cases of HBV infection were observed among vaccine non-responders, as well as 30 cases among those who had not completed vaccination.

CONCLUSION

We demonstrate the feasibility of including HBV vaccination in the services offered by a NEP, with completion of vaccination in a majority of HBV-susceptible PWID. The response to HBV vaccination among PWID was relatively low; however, the addition of up to three booster doses improved the response rate from 74.8 to 84.5%.

Memory T cells specific for HBV enumerated by a peptide-based cultured enzyme-linked immunospot assay in healthy HBV-vaccinated subjects

Hepatitis B vaccine is the most effective strategy to control hepatitis B virus (HBV) infection and disease. It is considered that an anti-HBs (antibodies against HBV surface antigen) titer >10 mIU/ml, measured shortly after a complete vaccination schedule, provides protection against infection. Approximately 4-10% of healthy individuals fail to respond to 3-dose vaccination. Long-term HBV-specific memory T-cell response has not been fully investigated, mainly due to the lack of a suitable assay. We quantified HBV-specific expandable memory T cells by using a cultured IFN-γ enzyme-linked immunospot (ELISPOT) assay. Cultured ELISPOT response to an overlapping peptide pool representing the complete L (large) HBV envelope polypeptide was evaluated in 41 healthy subjects vaccinated 15-20 y earlier and 5 unvaccinated. Plasma samples were tested for anti-HBs. Vaccinated subjects had significantly higher HBV-specific T-cellular response than unvaccinated (p = 0.0002). HBV-specific T-cell response was mainly mediated by CD4⁺ T cells. No concordance was found between cultured ELISPOT and anti-HBs data in vaccinated subjects. Thirty-one (76%) vaccinated subjects were responders (anti-HBs >10 mIU/ml). Nineteen (46%) vaccinated subjects were considered to be responders in cultured ELISPOT. Twenty-two (54%) vaccinated subjects were considered non-responders in cultured ELISPOT; 5 of them (23%) were also humoral non-responders. About 12% of healthy HBV-vaccinated subjects are both humoral and cellular non-responders. Although the prognostic value of this assay has not been established in terms of predictability for susceptibility to de-novo HBV infection, ELISPOT data suggest that these subjects may be at risk for HBV infection and disease, especially health care workers.

Immune response to second vaccination series of hepatitis B virus among booster dose non-responders

OBJECTIVE

To evaluate the response to second vaccination series among post-booster sero-negative children who had previously received compulsory HBV vaccination.

SUBJECTS AND METHODS

After given a booster dose to 1070 children, 103 of them failed to generate anamnestic response (anti-HBs <10 IU/L). Only 91/103 children received additional two doses of recombinant HBV vaccine (i.e. 2(nd) vaccination series) after 1 and 6 months post-booster. Blood sample was withdrawn aseptically one month later for quantitative assessment of anti-HBs to detect development of protective immune response (≥10 IU/L). Immunological vaccination failure was assigned to children who did not develop protective immune response after 2(nd) vaccination series.

RESULTS

Protective immune response was detected among 84/91 children (92.3%). While 7/91 (7.7%) whose age were ≥10 years did not respond and had post-booster undetectable anti-HBs. About 80% of children with post-booster detectable anti-HBs showed significant protective immune response (anti-HBs ≥100 IU/L) and higher GMT (299.1 ± 3.6 IU/L) compared to those with undetectable 60% and 106.2 ± 12.9 IU/L respectively (P<0.05). No significant difference was detected as regards gender or residence, P>0.05. All children with history of rheumatic fever (7 children) or diabetes mellitus (1 child) developed immune response after 2(nd) vaccination series.

CONCLUSION

A booster dose of HB vaccine may be unable to induce sufficient immunological response in children who had undetectable anti-HBs titers. Revaccination for non-responders is an important procedure to increase HBV protection rate.

Immune Responses to Single-Dose Versus Double-Dose Hepatitis B Vaccines in Healthcare Workers not Responding to the Primary Vaccine Series: A Randomized Clinical Trial

BACKGROUND

Recommendations to immunize healthcare workers (HCWs) against hepatitis B are well known. However, a proportion of individuals do not respond to the primary standard three-dose HB vaccination schedule.

OBJECTIVES

The current study aimed to evaluate whether a double-dose HB booster vaccine could induce better protective anti-HB titers than a single-dose booster in non-protected HCWs.

MATERIALS AND METHODS

This was a randomized clinical trial. A total of 91 HCWs not responding to the primary vaccine series in 2014 were enrolled. The participants were randomized into two groups that received a double dose of the HB vaccine containing 40 µg of antigen or a single dose of the HB vaccine containing 20 µg of antigen in three doses (at zero, one and six months after vaccination). Blood samples were collected before vaccinations and 28 days after the third dose to assess the seroconversion rate, according to the anti-HB antibody titer threshold of > 10 mIU/mL.

RESULTS

The seroconversion rates were 93.2% and 87.2% after the first booster doses of the double-dose and single-dose HB vaccines, respectively (P = 0.64). In the double-dose HB vaccine group, the seroconversion rate was 97.8% compared with 89.6% in the single-dose group following the second vaccine dose (P = 0.83). All of the participants in both groups were seroprotected after the third HB vaccine dose.

CONCLUSIONS

Both the single- and double-dose HB vaccines were adequately immunogenic, and the double-dose HB vaccine was not significantly more immunogenic than the single-dose vaccine in terms of the seroconversion rates of HCWs who had not responded to the primary vaccine series.

Intranasal Administration of Novel Chitosan Nanoparticle/DNA Complexes Induces Antibody Response to Hepatitis B Surface Antigen in Mice

The generation of strong pathogen-specific immune responses at mucosal surfaces where hepatitis B virus (HBV) transmission can occur is still a major challenge. Therefore, new vaccines are urgently needed in order to overcome the limitations of existing parenteral ones. Recent studies show that this may be achieved by intranasal immunization. Chitosan has gained attention as a nonviral gene delivery system; however, its use in vivo is limited due to low transfection efficiency mostly related to strong interaction between the negatively charged DNA and the positively charged chitosan. We hypothesize that the adsorption of negatively charged human serum albumin (HSA) onto the surface of the chitosan particles would facilitate the intracellular release of DNA, enhancing transfection activity. Here, we demonstrate that a robust systemic immune response was induced after vaccination using HSA-loaded chitosan nanoparticle/DNA (HSA-CH NP/DNA) complexes. Furthermore, intranasal immunization with HSA-CH NP/DNA complexes induced HBV specific IgA in nasal and vaginal secretions; no systemic or mucosal responses were detected after immunization with DNA alone. Overall, our results show that chitosan-based DNA complexes elicited both humoral and mucosal immune response, making them an interesting and valuable gene delivery system for nasal vaccination against HBV.

The mechanism of action of acid-soluble chitosan as an adjuvant in the formulation of nasally administered vaccine against HBV

Recently, numerous attempts have been made to evaluate the potential of chitosan as an adjuvant; however, few have explored the mechanism underlying the adjuvant activity of chitosan.

Applications of human hepatitis B virus preS domain in bio- and nanotechnology

Human hepatitis B virus (HBV) is a member of the family Hepadnaviridae, and causes acute and chronic infections of the liver. The hepatitis B surface antigen (HBsAg) contains the large (L), middle (M), and small (S) surface proteins. The L protein consists of the S protein, preS1, and preS2. In HBsAg, the preS domain (preS1 + preS2) plays a key role in the infection of hepatocytic cells by HBV and has several immunogenic epitopes. Based on these characteristics of preS, several preS-based diagnostic and therapeutic materials and systems have been developed. PreS1-specific monoclonal antibodies (e.g., MA18/7 and KR127) can be used to inhibit HBV infection. A myristoylated preS1 peptide (amino acids 2-48) also inhibits the attachment of HBV to HepaRG cells, primary human hepatocytes, and primary tupaia hepatocytes. Antibodies and antigens related to the components of HBsAg, preS (preS1 + preS2), or preS1 can be available as diagnostic markers of acute and chronic HBV infections. Hepatocyte-targeting delivery systems for therapeutic molecules (drugs, genes, or proteins) are very important for increasing the clinical efficacy of these molecules and in reducing their adverse effects on other organs. The selective delivery of diagnostic molecules to target hepatocytic cells can also improve the efficiency of diagnosis. In addition to the full-length HBV vector, preS (preS1 + preS2), preS1, and preS1-derived fragments can be useful in hepatocyte-specific targeting. In this review, we discuss the literature concerning the applications of the HBV preS domain in bio- and nanotechnology.

Serosurveillance of vaccine preventable diseases and hepatitis C in healthcare workers from Lao PDR

BACKGROUND AND AIMS

Healthcare workers (HCW) have an increased risk of exposure to infectious diseases and are a potential source of infections for their patients. The Lao People's Democratic Republic (Lao PDR) has no national policy regarding HCW vaccinations and routine vaccination coverage is low within the general population. This cross-sectional serostudy determines the level of exposure and risk of infection in Lao HCW against 6 vaccine preventable diseases and hepatitis C.

METHODS

1128 HCW were recruited from 3 central, 2 provincial and 8 district hospitals. Sera were tested by ELISA for the presence of antibodies and antigens to hepatitis B, hepatitis C, measles, rubella, varicella zoster, tetanus and diphtheria.

RESULTS

Only 53.1% of the HCW had protective anti-hepatitis B surface antigen antibodies (anti-HBs) with 48.8% having anti-hepatitis B core antibodies (anti-HBc), indicating previous exposure and 8.0% were hepatitis B surface antigen carriers. 3.9% were hepatitis C seropositive. Measles and rubella antibodies were detected in 95.4% and 86.2% of the HCW, with 11.9% of females being unprotected against rubella. Antibodies against varicella zoster, tetanus and diphtheria were detected in 95%, 78.8% and 55.3%, respectively. Seroprevalence varied according to age, gender and number of children.

CONCLUSION

An unacceptably high proportion of Lao HCW remain susceptible to infection with hepatitis B, diphtheria, tetanus and rubella. Furthermore, a high number of healthcare workers are chronically infected with hepatitis B and C viruses. These data emphasize the need for a robust HCW vaccination policy in addition to increased awareness within this subpopulation.

Hepatitis B virus PreS2 gene mutations in patients after hepatitis B vaccine immunization

AIM: To observe hepatitis B virus (HBV) PreS2 gene mutations in patients after hepatitis B vaccine immunization, and to discuss the relationship between hepatitis B vaccine immunization failure and PreS2 gene mutations.

METHODS: Forty-seven blood samples were collected from patients with chronic HBV infection after hepatitis B vaccine immunization who were treated at the Kunming Yan'an Hospital and the Third People's Hospital. HBV DNA was extracted from serum samples, and PreS2 gene fragments were amplified by PCR. The amplified gene fragments were analyzed by DNA sequencing. PCR products were obtained in 35 cases, and DNA sequencing was performed in 32 cases. There were 18 males and 14 females, and their age ranged from 19 to 56 years, with a mean value of 32.75 ± 10.22. The sequences of the amplifed PreS2 gene fragment sequences were analyzed with Chromas software and compared with sequenced deposited in Genbank with BLASTN. The results were analyzed using SPSS11.5 software.

RESULTS: The rate of PreS2 point mutations was 100% in the 32 specimens, including two (6.3%) cases of deletion mutations (6.3%), indicating that there may be deletion of amino acids such as Ile, Tyr, Phe, Gly, and Arg. Variation in the preS2 start codon (ATG) was not found in the 32 cases. There were a total of 517 point mutations, and preS2 base mutations had 11 types, namely, G-A, A-G, T-C, A-T, G-T, C-T, G-C, A-C, C-G, C-A, and T-A. The rate of different types of point mutations and the number of cases with different types of point mutations varied, with the rate of G-A mutation being highest and the greatest number of cases having the A-T mutation (P < 0.05). The rate of point mutations in different regions of the PreS2 gene also varied, with the middle region (nt 45-99) having a higher mutation rate and the upstream region having a lower mutation rate (P < 0.05).

CONCLUSION: There may be a correlation between PreS2 gene mutations and immunization failure, which will provide a theoretical basis for further study of the mechanism of hepatitis B vaccine immunization failure and guide the clinical practice. Gene therapy targeting these PreS2 gene mutations may become a new research direction of hepatitis B vaccine immunization.

Prevalence of Markers for Hepatitis B Virus and Vaccination Compliance Among Medical School Students in Italy

The prevalence of markers for hepatitis B virus (HBV) and the rate of compliance with HBV vaccination laws were investigated in a study at Padua University Medical School (Italy). Of 2,361 students, 385 (16.3%) tested negative for antibody to hepatitis B surface antigen. When vaccination was actively offered to these students, there was a low rate of compliance (47.0% [181 students]) but a good rate of seroconversion (93.1% [95 of 102 students]). Screening for HBV markers appears to be crucial to efforts to increase rates of vaccination coverage.

HBV vaccination status and response to hepatitis B vaccine among Iranian dentists, correlation with risk factors and preventive measures

BACKGROUND

Studies showed that HBV vaccination and consequent level of antibody are not completely adequate among dentists despite performance of highly exposure prone procedures.

OBJECTIVES

The objectives of the study were to evaluate the levels of responsiveness to HBV vaccine and to determine the occupational factors associated among dental staff.

MATERIALS AND METHODS

In total, 1612 dental health care workers were recruited. The level of anti-HBs was tested using a commercially enzyme-linked immunosorbent assay (ELISA). Data on demographic, risk factors associated with dental practice and level of protective procedures and occupational exposure aspects were collected through self-reported questionnaires.

RESULTS

Of 1538 vaccinated individuals, 55 (3.7%), 126 (8.4%) and 1309 (87.9%) had received one, two and full three doses of vaccine, respectively. One-hundred-seventy-six (11.5%) were nonimmune (anti-HBs < 10 IU/mL) and 1362 (88.5%) were immune (anti-HBs > 10 IU/ mL). 392/542 (72.3%) of dentists who received their third dose of vaccination less than five years before the commencement of study were completely immune compared to those who had completed all three recommended doses in a longer period (308/491, 64.3%) (P = 0.001). Fifty-eight (3.59%) of participants did not receive any HBV vaccine at all; however, they had positive results for anti-HBs, indicating a past HBV infection. Statistically, the levels of anti-HBs were significantly associated with gender, age, duration of dental practice engagement and regularly use of mask, glasses and shield.

CONCLUSIONS

Since dental care workers have a high risk of exposure to hepatitis virus, they should be advised to receive hepatitis B vaccine and it should be confirmed if they have acquired immunity to HBV by testing the level of anti-HBs.

Generation of hepatitis B virus PreS2-S antigen in Hansenula polymorpha

Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen (HBsAg) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus (HBV) PreS2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsAg, particularly in terms of cytotoxic T lymphocyte (CTL) reaction. In the current study, the HBV PreS2-S gene encoding an extra 26 amino acids (PreS2 C-terminus) located at the N-terminus of HBsAg was cloned into the pVCH1300 expression vector. PreS2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ∼ 15% and purity of ∼ 99%. In keeping with previous studies, ∼ 22 nm viruslike particles were detected using electron microscopy. The generated PreS2-S antigen will be further studied for efficacy and safty in animals.

Evaluation of hepatitis B surface antibody and specific gamma interferon response in health care workers after vaccination

Background:

Health care workers are at high risk of acquiring hepatitis B virus (HBV) infection through occupational exposure to blood or body fluids. Thus, the assessment of anti-HBs status after immunization is very important.

Objectives:

This study aimed to evaluate the measurement of HBsAb titer and specific gamma interferon response among the vaccinated health care workers in Golestan Hospital, Ahvaz, Iran.

Patients and Methods:

The blood samples of 39 health care workers, including 13 general surgeons, 10 anesthesiologists, 5 neurosurgeons, 3 general physicians, 1 orthopedist, 2 urologist and 5 nurses were collected during June 2013. All the participants had received HBV vaccine. They had received last vaccine dose from 2 months to 14 years ago. Their sera were tested for anti-hepatitis B antibody and HBc-IgG by the ELISA. Also, the evaluation of specific interferon γ response against HBsAg was carried out using ELISA test. The age of health care workers were between 24 and 58 years with the mean age of 34.3 ± 7.4 y.

Results:

Out of 39 sera, 22 (56.41%) had HBsAb titer above 100 IU/mL, 17 (43.6%) had titer below 100 IU/mL, 27 (69.2%) had positive specific HBsAg interferon γ, 8 (20.5%) cases had positive antibody response above 100IU, but negative for specific interferon γ and 3 (7.6%) cases were positive for HBc-IgG.

Conclusions:

Overall, 87.2% of the health care workers had immunity against HBV infection, which showed remarkable immunity response following HBV vaccination. Booster dose of HBV vaccine is recommended for those whose immunity are below 100 IU/mL.

Normal or defective immune response to Hepatitis B vaccine in patients with diabetes and celiac disease

A defective production of protective levels of antibodies to Hepatitis B (HB) vaccine is reported to occur in 4-10% of healthy subjects and a correlation with the presence of specific human leukocyte antigen (HLA) molecules, including DQ2, which also confers genetic predisposition to celiac disease (CD) and type I diabetes mellitus (T1DM), has been suggested.   The aim of this study was to analyze the serological response to HB vaccine and measles-containing vaccines in 69 diabetic patients (T1DM), 42 patients with celiac disease (CD) and 79 healthy control subjects (CT). The median interval between the third dose of HB vaccine and serum collection was 6.8, 3.5, and 4.7 years for T1DM, CD and CT groups, respectively. 50/69 (72%) T1DM patients, 32/42 (76%) CD patients and 61/79 (77%) CT subjects showed protective anti-HBs antibodies after vaccination, with no statistically significant difference. On the contrary, a lower statistically significant difference was found in the mean HBsAb level of T1DM subjects when compared with the other two groups. No correlation between HLA DQ2 expression in T1DM and vaccine response was detected. The comparison of serological response to measles after vaccination also showed no statistically significant differences in the three groups. Contrasting results between these data and those reported in the literature might be due to differences in the time intervals between vaccination and testing. Prospective studies in pathological and healthy groups with the same age at HBV vaccination and with the same time interval for blood sample collection to determine antibody titers are necessary in order to provide more conclusive data.

Serological response to one intradermal or intramuscular hepatitis B virus vaccine booster dose in human immunodeficiency virus-infected nonresponders to standard vaccination

Purpose:

Hepatitis B virus (HBV) vaccination is recommended for all human immunodeficiency virus (HIV)-infected patients without HBV immunity. However, serological response to standard HBV vaccination is frequently suboptimal in this population and the appropriate strategy for revaccination of HIV-infected nonresponders remained controversial. We aimed to determine the serological response to one booster dose of HBV vaccine given by intradermal (ID) or intramuscular (IM) route in HIV-positive nonresponders to standard HBV vaccination.

Materials and Methods:

In this study, 42 HIV-infected nonresponders were enrolled. We randomized them to receive either 10 μg (0.5 mL) for ID (20 cases) or 20 μg (1 mL) for IM (22 cases) administration of HBV vaccine as a one booster dose. After 1 month, anti-HBs titer was checked in all cases. A protective antibody response (seroconversion) defined as an anti-HBs titer ≥10 IU/L.

Results:

Seroconversion was observed in 47.6% of subjects after 1 ID dose. A total of 30% showed antibody titers above 100 IU/L. Except one case, all responders had CD4⁺ >200 cells/mm³. Mean anti-HBs titer was 146.5 ± 246 IU/L. After the one IM booster dose, seroconversion was observed in 50% of cases. A total of 36.3% of subjects had anti-HBs ≥100 IU/L. All responders had CD4⁺ >200 cells/mm³, except one case. Mean anti-HBs titer was 416.4 ± 765.6 IU/L. Responders showed significantly higher CD4⁺ cell counts, in comparison to nonresponders (P < 0.001).

Conclusions:

One booster dose administered IM or ID to HIV-infected nonresponders resulted in similar rates of seroconversion, overall response rate 50%. However, higher anti-HBs titers observed more frequently in IM group.

Long-term efficacy of the hepatitis B vaccine in a high-risk group

Chronic infection with hepatitis B virus (HBV) is a global health problem. In an attempt to control infection, worldwide HBV vaccination programs have been established. Saudi Arabia, an endemic area for HBV infection, established an HBV immunization program in 1989. This cross-sectional study evaluates the long-term protection of HBV vaccination 14-24 years after primary immunization in a high-risk group (clinical year medical students) at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. All participants had complete HBV immunization at birth or in early childhood. Hepatitis B surface antibody (anti-HBs) levels were obtained. An anti-HBs titer of <10 mIU/ml indicated no protection, while a titer of >10 mIU/ml was considered to represent protective immune status. A total of 238 students were included; they were predominantly females (n = 182, 76.5%). Mean age was 22.2 ± 1.1 years. Duration since primary vaccination was 19.8 ± 2.3 years. Female students were more likely to maintain long-term protection compared to males (62.1% and 58.8%, respectively). Anti-HBs levels were significantly low in many students after primary immunization. Testing medical students for anti-HBs levels may be warranted as they represent a high-risk population. The higher rate of vaccine failure in males than females requires further investigation as it may explain the higher prevalence of HBV in the male population.

Association between microRNA polymorphisms and humoral immunity to hepatitis B vaccine

To investigate whether selected single nucleotide polymorphisms (SNPs) in miR-146a, miR-196a2, miR-27a, miR-26a-1, miR-124 and miR-149 genes are associated with immune response to hepatitis B vaccine. The genotype and allele frequencies of SNPs were compared between the non-responders (n=77) and responders (n=207). The associations of the genotypes with antibody levels were assessed in the responders. Significant associations were observed between SNPs in miR-146a and miR-26a-1 genes and non-response to hepatitis B vaccine (p<0.05). In addition, SNPs in miR-146a and miR-27a genes were associated with variations in levels of antibodies to hepatitis B antigen. Thus, specific SNPs in microRNAs (miRNAs) genes may affect status of the hepatitis B vaccine induced protective humoral immune response. They also suggest that the three miRNAs play a role in modulating antibody responses to hepatitis B vaccine.

Clinical impact of hepatitis B and C virus envelope glycoproteins

Chronic infection by either hepatitis B virus (HBV) or hepatitis C virus (HCV) share epidemiological characteristics with risks for development of severe complications such as liver cirrhosis and hepatocellular carcinoma. HBV and HCV also share a high genetic variability. Among highly variable regions, viral genes encoding surface proteins (hepatitis B surface antigen, E1/E2 HCV glycoproteins) play key roles in the stimulation of the host-related immune response and viral entry into hepatocytes. Specific segments of HBV envelope proteins (preS1, “a” determinant) are crucial in the entry process into permissive cells. HCV entry is a complex multistep process involving multiple cell cofactors (glycosaminoglycans, low density lipoprotein receptor, SR-B1, CD81, claudin-1, occludin, EGFR, EphA2) in the interaction with HCV E1/E2 envelope glycoproteins. In vitro both viruses can be controlled by antibody-mediated neutralization targeting viral envelope, also essential in preventing HBV infection in vivo as observed through successful vaccination using HBs antigen. But preventive vaccination and/or therapeutic pressure can influence HBV and HCV variability. For HBV, the patterns of antiviral drug resistance in chronic hepatitis are complex and the original pol/S gene overlap has to be taken into account. Treatment-induced HBV mutations in pol could indeed generate S mutants with subsequent modified antigenicity or increased cancer induction. Variability of HBV and HCV envelope proteins combining high exposure to selective pressures and crucial functional roles require investigation in the context of diagnostic, vaccination and treatment tools. In this editorial a synthesis is performed of HBV and HCV envelope properties at the entry step and as antigenic proteins, and the subsequent clinical impact.

Chronic Schistosoma japonicum infection reduces immune response to vaccine against hepatitis B in mice

Background

Hepatitis 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 Findings

In 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/Significance

The 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.

Hepatitis B revaccination for healthcare workers who are anti-HBs-negative after receiving a primary vaccination series

INTRODUCTION

This study aimed to evaluate the response to hepatitis B (HB) revaccination of healthcare workers (HCW) who are negative for antibodies to HB surface antigen (anti-HBs) after a complete vaccination series.

METHODS

HCW whose anti-HBs test was performed > 90 days after a HB vaccination course were given a 4th dose. A post-vaccination test was done within 30 to 90 days.

RESULTS

One hundred and seventy HCW were enrolled: 126 (74.1%) were anti-HBs-positive after the 4th dose.

CONCLUSIONS

Rechecking anti-HBs after the 4th HB vaccine dose is a practical approach in case of post-vaccination tests performed >90 days after the full vaccination course.

Intramuscular vs intradermal route for hepatitis B booster vaccine in celiac children

AIM: To compare intradermal (ID) and intramuscular (IM) booster doses, which have been used in healthy and high risk subjects, such as healthcare workers, haemodialysis patients, human immunodeficiency virus patients, and renal transplant recipients unresponsive to initial hepatitis B vaccination, in celiac individuals.

METHODS: We conducted our study on 58 celiac patients, vaccinated in the first year of life, whose blood analysis had showed the absence of protective hepatitis B virus (HBV) antibodies. All patients had received the last vaccine injection at least one year before study enrolment and they had been on a gluten free diet for at least 1 year. In all patients we randomly performed an HBV vaccine booster dose by ID or IM route. Thirty celiac patients were revaccinated with recombinant hepatitis B vaccine (Engerix B) 2 μg by the ID route, while 28 celiac patients were revaccinated with Engerix B 10 μg by the IM route. Four weeks after every booster dose, the anti-hepatitis B surface (HBs) antibody titer was measured by an enzyme-linked immune-adsorbent assay. We performed a maximum of three booster doses in patients with no anti-HBs antibodies after the first or the second vaccine dose. The cut off value for a negative anti-HBs antibody titer was 10 IU/L. Patients with values between 10 and 100 IU/L were considered "low responders" while patients with an antibody titer higher than 1000 IU/L were considered "high responders".

RESULTS: No significant difference in age, gender, duration of illness, and years of gluten intake was found between the two groups. We found a high percentage of "responders" after the first booster dose (ID = 76.7%, IM = 78.6%) and a greater increase after the third dose (ID = 90%, IM = 96.4%) of vaccine in both groups. Moreover we found a significantly higher number of high responders (with an anti-HBs antibody titer > 1000 IU/L) in the ID (40%) than in the IM (7.1%) group, and this difference was evident after the first booster dose of vaccination (P < 0.01). No side effects were recorded in performing delivery of the vaccine by either the ID or IM route.

CONCLUSION: Our study suggests that both ID and IM routes are effective and safe options to administer a booster dose of HBV vaccine in celiac patients. However the ID route seems to achieve a greater number of high responders and to have a better cost/benefit ratio.

Optimisation of prime-boost immunization in mice using novel protein-based and recombinant vaccinia (Tiantan)-based HBV vaccine

BACKGROUND

A therapeutic vaccine for chronic hepatitis B virus (HBV) infection that enhances virus-specific cellular immune responses is urgently needed. The "prime-boost" regimen is a widely used vaccine strategy against many persistence infections. However, few reports have addressed this strategy applying for HBV therapeutic vaccine development.

METHODOLOGY/PRINCIPAL FINDINGS

To develop an effective HBV therapeutic vaccine, we constructed a recombinant vaccinia virus (Tiantan) containing the S+PreS1 fusion antigen (RVJSS1) combined with the HBV particle-like subunit vaccine HBVSS1 to explore the most effective prime-boost regimen against HBV. The immune responses to different prime-boost regimens were assessed in C57BL/C mice by ELISA, ELISpot assay and Intracellular cytokine staining analysis. Among the combinations tested, an HBV protein particle vaccine priming and recombinant vaccinia virus boosting strategy accelerated specific seroconversion and produced high antibody (anti-PreS1, anti-S antibody) titres as well as the strongest multi-antigen (PreS1, and S)-specific cellular immune response. HBSS1 protein prime/RVJSS1 boost immunization was also generated more significant level of both CD4+ and CD8+ T cell responses for Th1 cytokines (TNF-α and IFN-γ).

CONCLUSIONS

The HBSS1 protein-vaccine prime plus RVJSS1 vector boost elicits specific antibody as well as CD4 and CD8 cells secreting Th1-like cytokines, and these immune responses may be important parameters for the future HBV therapeutic vaccines.

Antibody levels in children after 10 years of vaccination against hepatitis B: a brazilian community-based study

INTRODUCTION: It is known that the hepatitis B (HB) vaccine is effective, but it is alarming that sudden drops of antibody levels may coincide with the onset of adolescence. METHODS: Antibody levels against HB vaccine surface antigen (anti-HBs) and HB vaccine core antigen (anti-HBc) were measured on the blood samples of children with a mean age of 11.4 years. RESULTS: About 54.8% had protective levels of anti-HBs. Of those who were anti-HBc-positive (4.4%), an average of 218.4 anti-HBs mIU/mL was found. CONCLUSIONS: Immunological protection was found in the majority of children. However, more studies are needed to elucidate the heritability of nonresponders and establish strategies against such events.

Hepatitis B vaccination of susceptible elderly residents of long term care facilities during a hepatitis B outbreak

Protection of older persons, particularly those with diabetes, against hepatitis B virus (HBV) infection is of growing concern because of increased reports of outbreaks among long-term care facility residents receiving assisted blood glucose monitoring. We evaluated hepatitis B vaccine immunogenicity among residents immunized in response to two such outbreaks in skilled nursing facilities during June 2009-July 2010. One hundred forty-eight (71%) of 209 residents were found to be susceptible to HBV infection. Of 105 patients who began a vaccination series with Twinrix(®) (0-, 1-, 6-month dosing), 86 (82%) completed the series and postvaccination testing. Of these, most were elderly (median age 79.5 years; range 45-101), female (56%), and African-American (51%). Twenty-nine (34%) vaccinated residents had post-vaccination hepatitis B surface antibody levels ≥10 mIU/ml. There were no significant differences in vaccine response by age, gender, race, diabetes status, body mass index, or current smoking status. Our findings indicate that a low proportion of skilled nursing facility residents achieved a seroprotective response after hepatitis B vaccination.

Demonstration of safety and enhanced seroprotection against hepatitis B with investigational HBsAg-1018 ISS vaccine compared to a licensed hepatitis B vaccine

Adults 40 years of age and older have been shown to be hypo-responsive immunologically to the currently available hepatitis B virus (HBV) vaccines. Three intramuscular doses of a Toll-like receptor 9 agonist, 1018 immunostimulatory sequence (1018 ISS) adjuvant, combined with recombinant hepatitis B surface antigen (HBsAg) demonstrated faster, superior, and more durable seroprotection than three doses of a licensed comparator HBV vaccine (Engerix-B(®)). This investigational vaccine, HBsAg-1018 ISS, was well tolerated with a safety profile similar to the comparator vaccine. These results suggest that HBsAg-1018 may be more effective in this hypo-responsive population.

Good response to HBsAg vaccine in dialysis patients is associated with high CD4+/CD8+ ratio

OBJECTIVE

Chronic renal failure is accompanied by various abnormalities of innate and acquired, cellular and humoral immunity. We aimed to investigate whether positive Candida skin test results, CD4+ and CD8+, before the first dose of vaccination could be a predictor for antibody response to hepatitis B vaccination and the relation of these parameters with hepatitis B antibody levels 1 month after the last dose of vaccination.

MATERIALS AND METHODS

The present study was carried out in 57 dialysis patients. All patients received recombinant hepatitis B vaccine (40 μg) given intramuscularly in the deltoid muscle in a four-dose schedule at 0, 1, 2, and 6 months. Candida skin test and lymphocyte subsets (CD4+ and CD8+) were determined before the first dose of vaccination and 1 month after the fourth inoculation of hepatitis B vaccine.

RESULTS

Ten patients (17.5%) were non-responders (HBsAb < 10 IU/L), while 47 patients (82.5%) were responders (HBsAb ≥ 10 IU/L). However, 29 patients (50.9%) were weak responders (HBsAb:10-100 IU/L), 18 patients (31.6%) good responders (HBsAb > 100 IU/L), which was determined 1 month after the fourth dose of vaccination. Thirty-nine patients (68.4%) and 44 patients (77.2%) were anergic to Candida skin test before the first dose and 1 month after fourth inoculation of hepatitis B vaccine, respectively. There was no relationship between Candida skin test and response to hepatitis B vaccination. Mean age was lower, and CD4+/CD8+ ratio measured both before and after vaccination was higher in good responders compared with that of weak responders and that of non-responders. Females were better responders than males.

CONCLUSION

High skin test anergy rate and low seroconversion rate after hepatitis B vaccination are important problems in patients on dialysis. Females, younger patients, and patients with higher CD4+/CD8+ ratio have better HBsAb antibody response to hepatitis B vaccination.

A genome-wide association study of hepatitis B vaccine response in an Indonesian population reveals multiple independent risk variants in the HLA region

We performed a two-stage genome-wide association study (GWAS) of antibody titer in 3614 hepatitis B vaccine recipients from Indonesia's Riau Archipelago, leading to the identification of at least three independent signals within the human leukocyte antigen (HLA) complex. These appear to implicate HLA-DR [rs3135363; P= 6.53 × 10(-22); odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.35-1.74]; HLA-DP, previously associated with the risk of chronic hepatitis B infection (rs9277535; P= 2.91 × 10(-12); OR = 0.72, 95% CI = 0.63-0.81); and a gene rich HLA Class III interval (rs9267665; P = 1.24 × 10(-17); OR = 2.05, CI = 1.64-2.57). The substantial overlap of these variants and those identified by GWAS of chronic hepatitis B infection confirms vaccine response as a model for infection, while suggesting that the vaccine is least effective in those most at risk of lifelong infection, following exposure to the virus.

Comparison of a bacteriophage-delivered DNA vaccine and a commercially available recombinant protein vaccine against hepatitis B

A bacteriophage lambda DNA vaccine expressing the small surface antigen (HBsAg) of hepatitis B was compared with Engerix B, a commercially available vaccine based on the homologous recombinant protein (r-HBsAg). Rabbits (five per group) were vaccinated intramuscularly at weeks 0, 5 and 10. Antibody responses against r-HBsAg were measured by indirect enzyme-linked immunosorbent assay, by limiting dilutions and by subtyping. Specific lymphocyte proliferation in vitro was also measured. After one vaccination, three of the five phage-vaccinated rabbits showed a strong antibody response, whereas no r-HBsAg-vaccinated animals responded. Following two vaccinations, all phage-vaccinated animals responded and antibody levels remained high throughout the experiment (220 days total). By 2 weeks after the second vaccination, antibody responses were significantly higher (P<0.05) in the phage-vaccinated group in all tests. After three vaccinations, one out of five r-HBsAg-vaccinated rabbit still failed to respond. The recognized correlate of protection against hepatitis B infection is an antibody response against the HBsAg antigen. When combined with the fact that phage vaccines are potentially cheap to produce and stable at a range of temperatures, the results presented here suggest that further studies into the use of phage vaccination against hepatitis B are warranted.

The response to hepatitis B vaccine: does it differ in celiac disease?

OBJECTIVES

There is a relationship between nonresponsiveness to hepatitis B virus (HBV) vaccine and certain human leukocyte antigen (HLA) genotypes. In healthy population, 4-10% vaccine recipients fail to produce protective levels of antibodies to the HBV vaccine after standard immunization depending upon age and the presence of various underlying diseases. Celiac disease (CD) is an HLA-associated immunological disease. It has been suggested that certain HLA haplotypes which are linked to CD are associated with nonresponse to HBV vaccine as well. The aim of this study is to assess the response to HBV vaccine prospectively in a group of CD and to explore the potential link between CD and HBV vaccine nonresponse by studying shared HLA haplotypes.

PATIENTS AND METHODS

Sixty-three previously diagnosed celiac patients who were on a strict gluten-free diet (GFD) and 54 healthy children were evaluated serologically for anti-HBs status. Celiac children who were anti-HBs negative at baseline were fully vaccinated prospectively, and reevaluated for the response to HBV vaccine. To estimate the role of HLA type in HBV vaccine response in celiac patients, a subgroup of both patients and control participants had HLA genotypes performed.

RESULTS

At enrollment, 27 (67.5%) children with CD and 48 (85.2%) healthy children were anti-HBs positive, and the difference between patients and controls was statistically significant (P<0.05). However, failure to respond to HBV vaccine was only 3.6% (response rate 96.4%) in prospectively vaccinated celiac patients. There was no relationship between HLA type and vaccine nonresponse in our study group.

CONCLUSION

The response to HBV vaccine in celiac children who were compliant to GFD is not different from a healthy population. CD may be one of the immune diseases associated with a high rate of HBV vaccine nonresponse but it might not be permanent and treatment with GFD and compliance to the treatment may ameliorate the immune response to HBV vaccine in celiac children.

Long-term protection against hepatitis B after newborn vaccination: 20-year follow-up

BACKGROUND

Hepatitis B vaccination in children born to hepatitis B surface antigen (HBsAg)-positive mothers considerably decreases the risk of vertical transmission. However, whether this protection against carriage of hepatitis B virus is maintained into early adulthood is as yet unknown.

PATIENTS AND METHODS

A combined passive-active immunization programme for newborns of HBsAg-positive mothers was initiated in the north-eastern part of the Czech Republic in 1988. The number of immunized newborns had reached 665 newborns by the end of 2006. All mothers of immunized infants were HBsAg-positive during pregnancy, and 34 (5%) were also hepatitis B e antigen (HBeAg)-positive. The immunization programme consists of providing newborns with protection at birth with hepatitis B immunoglobulin, followed by three 10-μg doses of plasma-derived or, since 1990, recombinant vaccine administered at 0, 1 and 6 months of life. Only 29 children of HBeAg-positive mothers received vaccine at 0, 1 and 2 months of life. Blood samples were obtained after immunization, at 2 years of age, and biennially thereafter. Samples were tested for HBsAg and hepatitis B surface and core antibodies (anti-HBs, anti-HBc).

RESULTS

The immunization schedules were completed in 640 children. A protective anti-HBs level after immunization was proven in 574 of 620 children (93%). Persistence of protective anti-HBs antibodies was detected in 70, 40 and 25% of children at 5, 10 and 15 years of age. Vertical transmission with chronic HBsAg carrier status was detected in two infants. Anti-HBc seroconversion was proven in ten children from 3 to 15 years of age. Natural boosting with an anti-HBs increase was detected in 38 children (twice in one child).

CONCLUSION

Our results show that combined active-passive immunization of newborns against hepatitis B provides persistent protection up to adolescence despite a frequent waning of anti-HBs antibodies, suggesting there is no need for booster vaccination during adolescence.

A vesicular stomatitis virus-based hepatitis B virus vaccine vector provides protection against challenge in a single dose

As one of the world's most common infectious diseases, hepatitis B virus (HBV) is a serious worldwide public health problem, with HBV-associated liver disease accounting for more than half a million deaths each year. Although there is an effective prophylactic vaccine currently available to prevent infection, it has a number of characteristics that are suboptimal: multiple doses are needed to induce long-lasting immunity, immunity declines over time, it does not elicit protection in some individuals, and it is not effective therapeutically. We produced a recombinant vesicular stomatitis virus (VSV)-based vaccine vector expressing the HBV middle envelope surface protein (MS) and found that this vector was able to efficiently generate a strong HBs-specific antibody response following a single immunization in mice. A single immunization with the VSV-MS vector also induced robust CD8 T-cell activation. The CD8 T-cell response was greater in magnitude and broader in specificity than the response generated by a vaccinia virus-based vaccine vector or by recombinant protein immunization. Furthermore, a single VSV-MS immunization provided protection against virus challenge in mice. Given the similar antibody titers and superior T-cell responses elicited from a single immunization, a VSV-based HBV vaccine may have advantages over the current recombinant protein vaccine.

Combined hepatitis A and B vaccine: providing a bright future for preventing hepatitis

The first combined hepatitis A and B vaccine has been available in the United States since 2001. The vaccine provides protection against viral hepatitis with rapid seroprotection and lasting immunogenicity. This review outlines the product's components, clinical efficacy and opportunities for use in special circumstances. The vaccine has a good safety profile and has good tolerability. The combined hepatitis A and B vaccine is a well studied vaccine that provides rapid seroconversion with a good safety profile.

Antibody response following hepatitis B vaccination in dialysis patients: does depression and life quality matter?

Previously, it was demonstrated that antibody production against hepatitis B virus (HBV) surface antigen (anti-HBs) achieved in hemodialysis patients is suboptimal. Decreased health-related quality of life (HRQOL) and depression is common among hemodialysis patients. This study evaluated whether HRQOL and depressive behavior are associated with antibody response against HBV surface antigen in hemodialysis patients. Depressive symptoms and HRQOL were assessed by Beck Depression Inventory (BDI) and Medical Outcomes Study Short Form (SF-36), respectively. Patients were separated into non-seroconversion (anti-HBs antibody titers <10 IU/L) and seroconversion (anti-HBs antibody titers > or =10 IU/L) groups. Among 188 patients, 37 (19.7%) were diagnosed as nonresponsive to vaccination (anti-HBs antibody titers <10 IU/L). Anti-HBs response is positively associated with Physical Component Summary Score of SF-36 (odds ratio: 1.44; P: 0.009) and albumin (odds ratio: 10.615, P: 0.007), and negatively with BDI score (odds ratio: 0.903, P: 0.007). We concluded that HRQOL and depression is closely related with antibody response following HBV vaccine in hemodialysis patients.

Care of HIV patients with chronic hepatitis B: updated recommendations from the HIV-Hepatitis B Virus International Panel

Nearly 10% of the estimated 36 million people having HIV worldwide suffer from chronic hepatitis B virus (HBV) infection. The advent of new antiviral agents against HBV and the recent availability of improved molecular diagnostic tools have revolutioned the management of HIV/HBV coinfected patients. The present study represents an update of the current knowledge about HBV/HIV coinfection and an intent to provide practical advise about how to give the best care to HIV-infected persons with chronic hepatitis B.

Aberrant lymphocyte activation precedes delayed virus-specific T-cell response after both primary infection and secondary exposure to hepadnavirus in the woodchuck model of hepatitis B virus infection

The contribution of virus-specific T lymphocytes to the outcome of acute hepadnaviral hepatitis is well recognized, but a reason behind the consistent postponement of this response remains unknown. Also, the characteristics of T-cell reactivity following reexposure to hepadnavirus are not thoroughly recognized. To investigate these issues, healthy woodchucks (Marmota monax) were infected with liver-pathogenic doses of woodchuck hepatitis virus (WHV) and investigated unchallenged or after challenge with the same virus. As expected, the WHV-specific T-cell response appeared late, 6 to 7 weeks postinfection, remained high during acute disease, and then declined but remained detectable long after the resolution of hepatitis. Interestingly, almost immediately after infection, lymphocytes acquired a heightened capacity to proliferate in response to mitogenic (nonspecific) stimuli. This reactivity subsided before the WHV-specific T-cell response appeared, and its decline coincided with the cells' augmented susceptibility to activation-induced death. The analysis of cytokine expression profiles confirmed early in vivo activation of immune cells and revealed their impairment of transcription of tumor necrosis factor alpha and gamma interferon. Strikingly, reexposure of the immune animals to WHV swiftly induced hyperresponsiveness to nonspecific stimuli, followed again by the delayed virus-specific response. Our data show that both primary and secondary exposures to hepadnavirus induce aberrant activation of lymphocytes preceding the virus-specific T-cell response. They suggest that this activation and the augmented death of the cells activated, accompanied by a defective expression of cytokines pivotal for effective T-cell priming, postpone the adaptive T-cell response. These impairments likely hamper the initial recognition and clearance of hepadnavirus, permitting its dissemination in the early phase of infection.