Antiviral Response across Genotypes after Treatment of Chronic Hepatitis B Patients with the Therapeutic Vaccine NASVAC or Pegylated Interferon.

An open-level, randomized and treatment-controlled clinical trial has shown that a therapeutic vaccine containing hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (NASVAC) is endowed with antiviral and liver protecting capacity and is safer than pegylated interferon (Peg-IFN) in patients with chronic hepatitis B (CHB). The present study provides information about the role of the hepatitis B virus (HBV) genotype in this phase III clinical trial. From a total of 160 patients enrolled in this trial, the HBV genotypes of 133 patients were characterized, and NASVAC induced a stronger antiviral effect (HBV DNA reduction below 250 copies per mL) than Peg-IFN. The antiviral effects and alanine aminotransferase levels were not significantly different among different HBV genotypes in NASVAC-treated patients. However, a significantly higher proportion of genotype-D patients receiving NASVAC showed better therapeutic effects, compared to genotype-D patients receiving Peg-IFN, with a marked difference of 44%. In conclusion, NASVAC seems to be a better alternative to Peg-IFN, especially in patients with HBV genotype-D patients. This reflects the attractiveness of NASVAC in countries where genotype D is highly prevalent. The mechanisms underlying the effect of HBV genotype are being studied in a new clinical trial.

Safety profile, antiviral capacity, and liver protection of a nasal therapeutic vaccine in patients with chronic hepatitis B: Five-year-follow-up outcomes after the end of treatment.

Introduction: There is a pressing need to develop novel drugs for treating patients with chronic hepatitis B (CHB), as commercially available antiviral drugs are endowed with safety and efficacy concerns. Methods: A phase III clinical trial was conducted with a therapeutic vaccine containing two antigens of the hepatitis B virus (HBV; named NASVAC) in 78 patients with CHB expressing both HBV DNA and elevated levels of alanine aminotransferase (ALT) in the blood. Five years after the end of treatment (EOT), 60 NASVAC-recipient patients were enrolled in this long-term follow-up study to evaluate the safety, antiviral potential, and liver-protective capacity of NASVAC. Results: NASVAC exhibited an excellent safety profile 5 years after EOT. The levels of HBV DNA in the sera were reduced in 55 of the 60 patients, and 45 of them were negative for HBV DNA in the sera. ALT levels were also normalized in 40 of the 60 patients 5 years after EOT. None of the patients receiving NASVAC developed liver cirrhosis or cancer. Discussion: The present study is the first to exhibit long-term follow-up data of a finite immune therapy for CHB that is safe and endowed with potent antiviral and liver-protecting capacities.

Activation of CD4 T cells during prime immunization determines the success of a therapeutic hepatitis B vaccine in HBV-carrier mouse models.

BACKGROUND & AIMS: We recently developed a heterologous therapeutic vaccination scheme (TherVacB) comprising a particulate protein prime followed by a modified vaccinia-virus Ankara (MVA)-vector boost for the treatment of HBV. However, the key determinants required to overcome HBV-specific immune tolerance remain unclear. Herein, we aimed to study new combination adjuvants and unravel factors that are essential for the antiviral efficacy of TherVacB. METHODS: Recombinant hepatitis B surface and core antigen (HBsAg and HBcAg) particles were formulated with different liposome- or oil-in-water emulsion-based combination adjuvants containing saponin QS21 and monophosphoryl lipid A; these formulations were compared to STING-agonist c-di-AMP and conventional aluminium hydroxide formulations. Immunogenicity and the antiviral effects of protein antigen formulations and the MVA-vector boost within TherVacB were evaluated in adeno-associated virus-HBV-infected and HBV-transgenic mice. RESULTS: Combination adjuvant formulations preserved HBsAg and HBcAg integrity for ≥12 weeks, promoted human and mouse dendritic cell activation and, within TherVacB, elicited robust HBV-specific antibody and T-cell responses in wild-type and HBV-carrier mice. Combination adjuvants that prime a balanced HBV-specific type 1 and 2 T helper response induced high-titer anti-HBs antibodies, cytotoxic T-cell responses and long-term control of HBV. In the absence of an MVA-vector boost or following selective CD8 T-cell depletion, HBsAg still declined (mediated mainly by anti-HBs antibodies) but HBV replication was not controlled. Selective CD4 T-cell depletion during the priming phase of TherVacB resulted in a complete loss of vaccine-induced immune responses and its therapeutic antiviral effect in mice. CONCLUSIONS: Our results identify CD4 T-cell activation during the priming phase of TherVacB as a key determinant of HBV-specific antibody and CD8 T-cell responses. IMPACT AND IMPLICATIONS: Therapeutic vaccination is a potentially curative treatment option for chronic hepatitis B. However, it remains unclear which factors are essential for breaking immune tolerance in HBV carriers and determining successful outcomes. Our study provides the first direct evidence that efficient priming of HBV-specific CD4 T cells determines the success of therapeutic hepatitis B vaccination in two preclinical HBV-carrier mouse models. Applying an optimal formulation of HBV antigens that activates CD4 and CD8 T cells during prime immunization provided the foundation for an antiviral effect of therapeutic vaccination, while depletion of CD4 T cells led to a complete loss of vaccine-induced antiviral efficacy. Boosting CD8 T cells was important to finally control HBV in these mouse models. Our findings provide important insights into the rational design of therapeutic vaccines for the cure of chronic hepatitis B.

Intranasal therapeutic vaccine containing HBsAg and HBcAg for patients with chronic hepatitis B; 18 months follow-up results of phase IIa clinical study.

AIMS: HBsAg loss with anti-HBs acquisition is considered a functional cure and ideal treatment goal for patients with CHB. Our group have reported the efficacy of therapeutic vaccine with HBsAg and HBcAg (NASVAC) by intranasal and subcutaneous injection. In this study, we investigated the safety and efficacy of newly developed CVP-NASVAC, which contained NASVAC with mucoadhesive carboxyl vinyl polymer (CVP) in the dedicated device. METHODS: A single dose, open-label, phase IIa clinical trial of CVP-NASVAC was conducted. Patients with CHB treated with nucleoside/nucleotide analogs (NAs) and HBV carriers not undergoing anti-HBV treatment were enrolled. CVP-NASVAC was injected through the nose for, in total, 10 times. Participants were followed-up for 18 months, and their HBsAg reduction and anti-HBs induction assessed as endpoints. RESULTS: Among the patients with CHB treated with NAs (n = 27) and HBV carriers without NAs (n = 36), 74.1% and 75.0% exhibited reductions in their baseline HBsAg, and the mean reductions were -0.1454 log10  IU/ml (p < 0.05) and -0.2677 log10  IU/ml (p < 0.05), respectively. Anti-HBs antibody was detected in 40.7% and 58.3% of patients treated with and without NAs, respectively. Six of 71 (9.5%) patients were functionally cured after the CVP-NASVAC treatment. CONCLUSIONS: Anti-HBs induction and HBsAg reduction was observed after CVP-NASVAC treatment in some patients with CHB. The CVP-NASVAC is a safe treatment, which might expect to achieve functional cure for patients with CHB.

Impact of the Route and Schedule of Immunization on the Serological and Virological Response of Chronic Hepatitis B Patients Treated with HeberNasvac.

HeberNasvac is a recently developed therapeutic vaccine for chronic hepatitis B (CHB) administered by intranasal (IN) and subcutaneous (SC) routes in a 14 days/10 doses schedule. To compare different schedules and routes of immunizations, a group of patients received four different vaccination regimens in a placebo-controlled factorial study. Subsequently, patients were followed for a minimum time of 48 weeks. Samples collected at the end of the follow-up were compared with initial samples. Groups I and II received the product by IN/SC routes, every 14 and 7 days, respectively. Groups III and IV were treated by SC route alone following a 14 and 7 days schedule. A group of 21 CHB patients received the vaccine in four different schedules and eight patients received placebo for a total of 29 patients enrolled. The 61.9% of vaccinees reduced their VL ≥2Log compared with baseline levels and 25% in placebo group. The 47.6% of vaccines reduced HBV levels to undetectable, 25% in placebo. HBeAg loss and seroconversion to anti-HBeAg was only achieved in vaccinees, 4 out of 9 (44.4%), and 40% (8 out of 20) developed anti-HBs response, none in placebo group. Reduction of HBsAg level in ≥1Log was achieved in the 35.0% of vaccinees and in none of the placebo-treated patients. Considering the individual and factorial analysis, significant HBV DNA reduction was detected in groups I and II, immunized by IN/SC routes. A significantly higher proportion of patients reducing VL to ≥2Log was also detected grouping the patients treated by IN/SC routes (G I + II) and grouping those inoculated every 14 days (G I + III), with 72.7% and 63.6%, respectively, compared with the placebo group (25.0%). The patients immunized every 14 days (G I + G III) also reduced the HBsAg levels compared with baseline. In conclusion, after more than 48 weeks of treatment-free follow-up, HeberNasvac-treated patients demonstrated superior responses compared with the placebo group in terms of antiviral and serological responses. The factorial analysis evidenced that the schedule combining the IN route of immunization and the frequency of 14 days resulted in the stronger antiviral and serological responses. Present results support the study of IN-only immunization schedules in future and was consistent with previous results. Long-lasting follow-ups were done to explore histological variables and the progression of serological variables in order to detect late responders. How to cite this article: Freyre FM, Aguiar JA, Cinza Z, et al. Impact of the Route and Schedule of Immunization on the Serological and Virological Response of Chronic Hepatitis B Patients Treated with HeberNasvac. Euroasian J Hepato-Gastroenterol 2023;13(2):73-78.

Action Mechanisms and Scientific Rationale of Using Nasal Vaccine (HeberNasvac) for the Treatment of Chronic Hepatitis B.

Nasvac (HeberNasvac®) is a novel therapeutic vaccine for chronic hepatitis B (CHB). This product is a formulation of the core (HBcAg) and surface (HBsAg) antigens of the hepatitis B virus (HBV), administered by nasal and subcutaneous routes, in a distinctive schedule of immunizations. In the present review article, we discuss the action mechanisms of HeberNasvac, considering the immunological properties of the product and their antigens. Specifically, we discuss the capacity of HBcAg to activate different pathways of innate immunity and the signal transduction after a multi-TLR agonist effect, and we review the results of recent clinical trials and in vitro studies. Aimed at understanding the clinical results of Nasvac and other therapeutic vaccines under development, we discuss the rationale of administering a therapeutic vaccine through the nasal route and also the current alternatives to combine therapeutic vaccines and antivirals (NUCs). We also disclose potential applications of this product in novel fields of immunotherapy.

Innovative Therapies Targeting the Virus and the Host for Treating Chronic Hepatitis B Virus Infection: From Bench to Bedside.

Chronic hepatitis B (CHB) is a highly complicated pathological process in which the disease is initiated by the hepatitis B virus (HBV); however, host immune responses are primarily responsible for variable extents of liver damage. If the patients with CHB remain untreated, many CHB patients will eventually develop complications like cirrhosis of the liver (LC) and hepatocellular carcinoma (HCC). In 2019, an estimated 882,000 patients died due to HBV-related complications worldwide. Accordingly, several drugs with antiviral properties have been used to treat CHB patients during the last four decades. However, the treatment outcome is not satisfactory because viral suppression is not usually related to the containment of progressive liver damage. Although proper reconstruction of host immunity is essential in CHB patients, as of today, there is no acceptable immune therapeutic protocol for them. These realities have exposed new, novel, and innovative therapeutic regimens for the management of CHB patients. This review will update the scope and limitation of the different innovative antiviral and immune therapeutic approaches for restoring effective host immunity and containing the virus in CHB patients to block progression to LC and HCC.

Sustained Antiviral and Liver Protection by a Nasal Therapeutic Vaccine (NASVAC, Containing Both HBsAg and HBcAg) in Patients with Chronic Hepatitis B: 2-Year Follow-Up of Phase III Clinical Trial.

A phase III clinical trial in treatment-naïve patients with chronic hepatitis B (CHB) revealed the safety and considerable therapeutic efficacy of a vaccine containing both hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (NASVAC) at the end of treatment (EOT) and 24 weeks after EOT. Two years after EOT, we checked HBV DNA, alanine aminotransferase (ALT), and hepatitis B e antigen (HBeAg). The data reveal that 33 of 66 NASVAC-recipient CHB patients became negative for HBV DNA in the blood two years after EOT. The ALT levels were within the upper limit of normal (ULN) in 37 patients, although all 66 CHB patients had elevated ALT (above ULN) before the start of therapy. Out of the total twelve HBeAg-positive patients, eight patients became negative for HBeAg. None of the patients developed cirrhosis of the liver within this period. NASVAC is a finite treatment regimen with sustained antiviral and liver-protecting properties. This study is the first to report follow-up data of immune therapy for CHB. NASVAC, an immune therapy of finite duration, is endowed with sustained antiviral and liver protection properties in CHB patients.

The Safety and Efficacy of a Therapeutic Vaccine for Chronic Hepatitis B: A Follow-Up Study of Phase III Clinical Trial.

The objective of the present study was to assess the safety and efficacy of a therapeutic vaccine containing both HBsAg and HBcAg (NASVAC) in patients with chronic hepatitis B (CHB) three years after the end of treatment (EOT) as a follow-up of a phase III clinical trial. NASVAC was administered ten times by the nasal route and five times by subcutaneous injection. A total of 59 patients with CHB were enrolled. Adverse events were not seen in any of the patients. Out of the 59 CHB patients, 54 patients exhibited a reduction in HBV DNA, compared with their basal levels. Although all the patients had alanine transaminase (ALT) above the upper limit of normal (>42 IU/L) before the commencement of therapy, the levels of ALT were within the ULN level in 42 patients. No patient developed cirrhosis of the liver. The present study, showing the safety and efficacy of NASVAC 3 years after the EOT, is the first to report follow-up data of an immune therapeutic agent against CHB. NASVAC represents a unique drug against CHB that is safe, of finite duration, can be administered by the nasal route, is capable of reducing HBV DNA and normalizing ALT, and contains hepatic fibrosis.

Treatment of chronic hepatitis B naïve patients with a therapeutic vaccine containing HBs and HBc antigens (a randomized, open and treatment controlled phase III clinical trial).

CONTEXT: Current drugs for chronic hepatitis B therapy have a poor efficacy in terms of post-treatment sustained viral suppression and generate important side effects during and after therapy. Therapeutic vaccination with HBV antigens is an attractive alternative to test. OBJECTIVE: Evaluating the efficacy of a therapeutic vaccine candidate (designated NASVAC) containing both hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) versus pegylated interferon (Peg-IFN) in naïve chronic hepatitis B patients. DESIGN, SETTING, PARTICIPANTS: An open phase III, randomised and treatment controlled clinical trial was conducted in a total of 160 CHB patients, allocated into two groups of 80 patients each to receive NASVAC or Peg-IFN. The vaccine formulation comprised 100 µg of each HBsAg and HBcAg, and was administered in 2 cycles of 5 doses. The control group received 48 subcutaneous injections of Peg-IFN alfa 2b, 180 µg per dose, every week, for 48 consecutive weeks. MAIN OUTCOME MEASURE: The primary outcome measure was in relation with the proportion of patients showing reduction of the viral load under the limit of detection (250 copies/mL) after 24 weeks of treatment completion. RESULTS: Sustained control of HBV DNA was significantly more common in NASVAC group (p<0.05) at 24 weeks of follow up. NASVAC-induced increases of alanine aminotransferases (ALT) were detected in 85% patients after 5 nasal vaccinations, although seen in only 30% of patients receiving Peg-IFN. At the end of treatment (EOT) antiviral effect was comparable in both NASVAC and Peg-IFN groups. Clearance of Hepatitis B e antigen (HBeAg) was also more frequent in NASVAC group compared to Peg-IFN recipients. A lower progression to cirrhosis was found in NASVAC group compared to Peg-IFN group. CONCLUSION: Nasvac induced a superior reduction of the viral load under the limit of detection compared to Peg-IFN treatment. It is a safe and efficacious finite alternative of antiviral treatment for CHB patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT 01374308.

Nasal route favors the induction of CD4+ T cell responses in the liver of HBV-carrier mice immunized with a recombinant hepatitis B surface- and core-based therapeutic vaccine.

Immunization routes and number of doses remain largely unexplored in therapeutic vaccination. The aim of the present work is to evaluate their impact on immune responses in naïve and hepatitis B virus (HBV)-carrier mouse models following immunization with a non-adjuvanted recombinant vaccine comprising the hepatitis B surface (HBsAg) and core (HBcAg) antigens. Mice were immunized either by intranasal (i.n.), subcutaneous (s.c.) or simultaneous (i.n. + s.c.) routes. Humoral immunity was detected in all the animal models with the induction of a potent antibody (Ab) response against HBcAg, which was stronger than the anti-HBs response. In the HBV-carrier mouse model, the anti-HBs response was predominantly subtype-specific and preferentially induced by the i.n. route. However, the Ab titers were not sufficient to clear the high concentration of HBsAg present in the sera of these mice. The i.n. route was the most efficacious at inducing cellular immune responses, in particular CD4+ T cells. In naïve mice, cellular responses in spleen were strong and mainly due to CD4+ T cells whereas the CD8+ T-cell response was low. In HBV-carrier mice, high frequencies of HBs-specific CD4+ T cells secreting interferon (IFN)-γ, interleukin (IL)-2 and tumor necrosis factor (TNF)-α were found in liver only after i.n. immunization. Increased frequencies of CD4+ T cells expressing the integrin CD49a in liver suggest a role of nasal route in the cellular homing process. Multiple dose schedules appear to be a prerequisite for protein-based immunization in order to overcome immunotolerance in HBV-carrier mice. These findings provide new avenues for further preclinical and clinical development.

High Functional Stability of a Low-cost HBV DNA qPCR Primer Pair and Plasmid Standard.

AIM: We studied the functional stability of a primer pair and the standard curve based on a plasmid carrying full-length HBV genome, from a novel low-cost real-time quantitative polymerase chain reaction (qPCR) assay. The assay was developed at the Center for Genetic Engineering and Biotechnology (CIGB) in Havana, to quantify the serum hepatitis B virus (HBV) DNA from chronic HBV-infected (CHB) patients. MATERIALS AND METHODS: In-house generated oligonucleotides and plasmids were incubated at 37°C during 1 month and compared with the same materials incubated at -20, 4, and 25°C during the same time in qPCR experiments. RESULTS: This work shows that the oligonucleotide pair and the plasmid for the quantitative standard curve are functionally stable in severe temperature conditions during 1 month. Polymerase chain reaction amplification with both materials after its incubation 30 days at 37°C produced similar cycle threshold (CT) values and similar degree of sample quantifications compared with the same materials preserved using the conventional storage conditions at -20°C. CONCLUSION: These results are indicative of the robustness of this low-cost qPCR system for HBV DNA quantification. These results also support that this qPCR assay can be used as a low-cost technology in clinical studies to monitor the viral load changes of serum HBV DNA of CHB patients, which could be used by poor people of third world countries, where there are frequent blackouts and temperature changes that can hinder the primer and plasmid stability. HOW TO CITE THIS ARTICLE: Aguiar J, García G, León Y, Canales E, Silva JA, Gell O, Estrada R, Morán I, Muzio V, Guillén G, Pentón E, Aguilar JC. High Functional Stability of a Low-cost HBV DNA qPCR Primer Pair and Plasmid Standard. Euroasian J Hepato-Gastroenterol 2016;6(1):19-24.

In vitro stimulation with HBV therapeutic vaccine candidate Nasvac activates B and T cells from chronic hepatitis B patients and healthy donors.

Hepatitis B virus (HBV) chronic infections remain a considerable health problem worldwide. The standard therapies have demonstrated limited efficacy, side effects or need life-long treatments. Nowadays therapeutic vaccination is a promising option. Recently, we developed a new vaccine formulation called Nasvac, based on the combination of surface and core antigens from HBV. Clinical trials already performed showed good efficacy in virus control. However, the exact mode of action of Nasvac formulation remains unclear. So far the functional impairment of DCs during persistent HBV infection is a controversial issue. On the other hand, it is known that B cells may function as antigen presenting cells (APC) activating T cells. The hepatitis B core antigen contained in Nasvac vaccine is able to bind and activate a high frequency of naive human B cells. In the present study the surface expression of activation and exhaustion markers on B cells and the subsequent activation of T cells after in vitro stimulation with Nasvac antigens were evaluated in chronic HBV patients and healthy donors. B- and T-cell phenotype and proliferation were assessed by flow cytometry. Our results indicate that in contrast to exhaustions markers B cell activation markers were increased on both study groups after Nasvac stimulation. A shift toward an activation phenotype was observed for both B and T cells. The present work suggests that B cells could act as efficient APCs for Nasvac antigens in humans, which might suggest the use of activated B cells as immunotherapeutic strategy for chronic hepatitis B.

Agresiones contra personal médico en emergencia del Hospital Nacional Arzobispo Loayza. Diciembre 2013 - Enero 2014 / Attacks against medical personnel in emergency at the National Hospital Arzobispo Loayza. December 2013 - January 2014

OBJETIVOS: Determinar los factores relacionados a la ocurrencia de las agresiones al personal médico de Emergencia del Hospital Nacional Arzobispo Loayza en los meses de Diciembre 2013-Enero 2014. DISEÑO DE ESTUDIO: estudio, transversal, descriptivo. LUGAR: Emergencias Hospital Nacional Arzobispo Loayza. MATERIALES Y METODOS: Encuestas a personal médico de emergencia de HNAL. RESULTADOS: El personal médico de pediatría con un 92 por ciento fue la especialidad que sufrió más agresiones, seguida de medicina interna con un 76 por ciento, cirugía 75 por ciento, y gineco-obstetricia con un 68 por ciento de personal agredido. El grupo etario de 20 a 28 años con 39 por ciento fue el más agredido. La población masculina con el 53 por ciento fue la más agredida. La población que sufrió agresiones más de tres veces en el último año fue el 17 por ciento. La mayor cantidad de agresiones fueron las verbales de pacientes con un 58 por ciento. Las agresiones fueron cometidas por una sola persona en un 66 por ciento. El 69 por ciento de agresiones se cometieron mientras el personal médico estaba acompañado por colegas. La respuesta ante la agresión fue tratar de controlar la situación mediante el diálogo con un 82 por ciento. La sensación de inseguridad en emergencia fue 58,6 por ciento. El principal desencadenante de la agresión fue por demora en atención 52 por ciento. CONCLUSIONES: El personal médico de emergencia de pediatría es el más agredido, la población más agredida son los internos. La población masculina es la que sufre más agresiones, la principal causa de agresión fue la demora en la atención.

OBJECTIVES: Determine the factors related to the occurrence of assaults on emergency medical personnel at National Hospital Arzobispo Loayza in the months of December 2013-January 2014. STUDY DESIGN: cross-sectional study, descriptive. LOCATION: Emergency of National Hospital Arzobispo Loayza. MATERIALS AND METHODS: Surveys emergency medical personnel HNAL. RESULTS: Pediatric medical staff with 92 per cent was the specialty that suffered more attacks, followed by internal medicine with 76 per cent, surgery 75 per cent, gynecology and obstetrics with 68 per cent of staff assaulted; the age group 20 to 28 years with 39 per cent was the most attacked. The male population with 53 per cent was the most attacked. The population suffered more attacks than three times in the last year was 17 per cent. As many attacks were verbal patient with 58 per cent. The attacks were committed by one person in 66 per cent. 69 per cent of assaults were committed while the medical staff was accompanied by colleagues. The response to the attack was to try to control the situation through dialogue with 82 per cent. The feeling of insecurity in emergency was 58.6 per cent. The main trigger of aggression delay in care was 52 per cent. CONCLUSIONS: The pediatric medical staff is the most attacked, the medical intern was the most attacked, the male population is suffering more attacks and the leading cause of aggression was the delay in care.

Therapeutic potential of a combined hepatitis B virus surface and core antigen vaccine in patients with chronic hepatitis B.

PURPOSE: The safety and clinical efficacy of a vaccine containing both hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (HBsAg/HBcAg) were evaluated in patients with chronic hepatitis B (CHB). METHODS: Eighteen patients with CHB were administered a vaccine containing 100 µg of HBsAg and 100 µg of HBcAg. The vaccine was administered ten times at 2-weekly intervals, the first five times via the nasal route only and the subsequent five times via both nasal and subcutaneous routes. The safety and efficacy of this therapeutic approach were assessed by periodic assessment of the patients' general condition, viral kinetics, and biochemical parameters during treatment and 24 and 48 weeks after therapy. The production of cytokines by peripheral blood mononuclear cells (PBMC) and antigen-pulsed dendritic cells (DC) was evaluated to assess the immunomodulatory effects of the HBsAg/HBcAg vaccine in CHB patients. RESULTS: The HBsAg/HBcAg vaccine was safe in all patients. No flare of HBV DNA or alanine aminotransferase (ALT) was recorded in any patient. Sustained HBV DNA negativity and persistently normalized ALT were detected in 9 (50 %) and 18 (100 %) patients with CHB, respectively. PBMC and HBsAg/HBcAg-pulsed DCs from HBsAg/HBcAg-vaccinated CHB patients produced significantly higher levels of various cytokines [interleukin 1ß (IL-1ß), IL-6, IL-8, IL-12, and tumor necrosis factor α (TNF-α)] than those from control unvaccinated CHB patients (p < 0.05) after stimulation with HBsAg/HBcAg in vitro. CONCLUSION: HBsAg/HBcAg vaccine seems a safe and efficient therapeutic approach for patients with CHB.

Optimization of immune responses induced by therapeutic vaccination with cross-reactive antigens in a humanized hepatitis B surface antigen transgenic mouse model.

The absence of relevant animal models of chronic hepatitis B virus (HBV) infection has hampered the evaluation and development of therapeutic HBV vaccines. In this study, we generated a novel transgenic mouse lineage that expresses human class I and II HLA molecules and the hepatitis B surface antigen (HBsAg). HBsAg and hepatitis B core antigen (HBcAg) administered as plasmid DNAs and recombinant proteins, either alone or in combination, were evaluated as therapeutic vaccine candidates in this mouse model. Our results emphasize the importance of the route of administration in breaking HBsAg tolerance. Although immunizing the transgenic mice with DNA encoding homologous HBsAg was sufficient to induce CD8+ T-cell responses, HBsAg from a heterologous subtype was required to induce a CD4+ T-cell response. Importantly, only prime-boost immunization protocols that combined plasmid DNA injection followed by protein injection induced the production of antibodies against the HBsAg expressed by the transgenic mice.

The effect of the parenteral route of administration on the immune response to simultaneous nasal and parenteral immunizations using a new HBV therapeutic vaccine candidate.

Chronic hepatitis B is a major health problem, with more than 350 million people infected worldwide. Available therapies have limited efficacy and require long-term continuous and expensive treatments, which often lead to the selection of resistant viral variants and rarely eliminate the virus. Immunotherapies have been investigated as a promising new approach. Several vaccine formulations have been clinically tested in chronic patients, none of which have clearly demonstrated efficacy so far. In this study we evaluated a new vaccination strategy comprising the simultaneous co-administration by the nasal and parenteral routes of a multicomponent vaccine formulation in BALB/C and HBsAg-transgenic mice. The formulation under study contains the surface and nucleocapsid antigens of the HBV, and was co-administered by the nasal route and three parenteral routes. For parenteral administration we also evaluated the immunogenicity of the antigenic mixture with alum or without the adjuvant. The immune response was evaluated by ELISA and IFN-γ ELISPOT assays. Our results indicate that all variants generated a strong antibody response in the sera against both antigens, but differed in their capacity to induce cellular immune responses against the surface antigen. Mice immunized by the nasal and subcutaneous routes without alum generated the highest IFN-γ-secreting CD8+ T-cell response, and results in this transgenic mouse model showed that there is no need to include alum. In conclusion, our results indicate that the immunization routes have to be carefully selected before carrying out clinical trials to optimize the immune response and promote further clinical development.

Vaccine adjuvants: current state and future trends.

The problem with pure recombinant or synthetic antigens used in modern day vaccines is that they are generally far less immunogenic than older style live or killed whole organism vaccines. This has created a major need for improved and more powerful adjuvants for use in these vaccines. With few exceptions, alum remains the sole adjuvant approved for human use in the majority of countries worldwide. Although alum is able to induce a good antibody (Th2) response, it has little capacity to stimulate cellular (Th1) immune responses which are so important for protection against many pathogens. In addition, alum has the potential to cause severe local and systemic side-effects including sterile abscesses, eosinophilia and myofascitis, although fortunately most of the more serious side-effects are relatively rare. There is also community concern regarding the possible role of aluminium in neurodegenerative diseases such as Alzheimer's disease. Consequently, there is a major unmet need for safer and more effective adjuvants suitable for human use. In particular, there is demand for safe and non-toxic adjuvants able to stimulate cellular (Th1) immunity. Other needs in light of new vaccine technologies are adjuvants suitable for use with mucosally-delivered vaccines, DNA vaccines, cancer and autoimmunity vaccines. Each of these areas are highly specialized with their own unique needs in respect of suitable adjuvant technology. This paper reviews the state of the art in the adjuvant field, explores future directions of adjuvant development and finally examines some of the impediments and barriers to development and registration of new human adjuvants.

Tendencia de aparición de enfermedad periodontal en jóvenes entre 13 y 17 años / Trend of periodontal disease appearance among 13-to-17 yerar-old juvenile population

En este estudio de tipo descriptivo y diseño no experimental se buscó identificar la tendencia de aparición de la enfermedad periodontal (gingivitis, alteraciones mucogingivales y periodontitis juvenil) en jóvenes con edades entre 13 y 17 años de edad. Se examinó una población de 117 jóvenes, 87 hombres y 30 mujeres que no tuvieran compromiso sistémico ni tratamiento con aparatología ortodóntica fija actual. La evaluación periodontal fue realizada por un solo examinador y con sondas periodontales milimitradas y radiografías periapicales a todos los dientes presentes. Se analizaron margen, bolsa, hemorragia y línea mucogingival. Los resultados obtenidos fueron analizados por medio de estadística descriptiva. Se concluyó que el 100 por ciento de la muestra presentó algún tipo de enfermedad periodontal

La morbilidad en la colecistectomía laparoscópica: experiencia de 600 casos / Morbidity in laparoscopic cholecystectomy: experience or 600 cases

La colecistectomía laparoscópica en la presente experiencia de 600 casos, constituye un procedimiento de baja morbilidad en cirugía electiva y en manos entrenadas. Sus indicaciones se han ampliado notoriamente y su combinación con la cirugía endoscópica permite un correcto manejo de la vía biliar principal. Se demuestra que la efracción vesicular tiene menos relevancia en cuanto a infecciones posoperatorias que el abandono de cálculos. Se analizan las causas y el número de conversiones. Se concluye que la colecistectomía laparoscópica es el tratamiento de elección para la litiasis biliar en la mayoría de los casos