A tetravalent nanoparticle vaccine elicits a balanced and potent immune response against dengue viruses without inducing antibody-dependent enhancement.

Dengue fever is a global health threat caused by the dengue virus (DENV), a vector-borne and single-stranded RNA virus. Development of a safe and efficacious vaccine against DENV is a demanding challenge. The greatest pitfall in the development of vaccines is antibody-dependent enhancement (ADE), which is closely associated with disease exacerbation. We displayed the modified envelope proteins from the four serotypes of the DENV on a 24-mer ferritin nanoparticle, respectively. This tetravalent nanoparticle vaccine induced potent humoral and cellular immunity in mice without ADE and conferred efficient protection against the lethal challenge of DENV-2 and DENV-3 in AG6 mice. Further exploration of immunization strategies showed that even single-dose vaccination could reduce pathologic damage in BALB/c mice infected with high doses of DENV-2. Treatment with cyclic-di-guanosine monophosphate facilitated a higher titer of neutralizing antibodies and a stronger type-1 T-helper cell-biased immune response, thereby revealing it to be an effective adjuvant for dengue nanoparticle vaccines. These data suggest that a promising tetravalent nanoparticle vaccine could be produced to prevent DENV infection.

Invariant NKT cell-augmented GM-CSF-secreting tumor vaccine is effective in advanced prostate cancer model.

Invariant natural killer T cells (iNKT cells) express a semi-invariant T cell receptor that recognizes certain glycolipids (including α-galactosylceramide, αGC) bound to CD1d, and can induce potent antitumor responses. Here, we assessed whether αGC could enhance the efficacy of a GM-CSF-producing tumor cell vaccine in the transgenic SV40 T antigen-driven TRAMP prostate cancer model. In healthy mice, we initially found that optimal T cell responses were obtained with αGC-pulsed TRAMP-C2 cells secreting GM-CSF and milk fat globule epidermal growth factor protein-8 (MFG-E8) with an RGD to RGE mutation (GM-CSF/RGE TRAMP-C2), combined with systemic low dose IL-12. In a therapeutic model, transgenic TRAMP mice were then castrated at ~ 20 weeks, followed by treatment with the combination vaccine. Untreated mice succumbed to tumor by ~ 40 weeks, but survival was markedly prolonged by vaccine treatment, with most mice surviving past 80 weeks. Prostates in the treated mice were heavily infiltrated with T cells and iNKT cells, which both secreted IFNγ in response to tumor cells. The vaccine was not effective if the αGC, IL-12, or GM-CSF secretion was eliminated. Finally, immunized mice were fully resistant to challenge with TRAMP-C2 cells. Together these findings support further development of therapeutic vaccines that exploit iNKT cell activation.

Rotavirus spike protein ΔVP8* as a novel carrier protein for conjugate vaccine platform with demonstrated antigenic potential for use as bivalent vaccine.

Conjugate vaccine platform is a promising strategy to overcome the poor immunogenicity of bacterial polysaccharide antigens in infants and children. A carrier protein in conjugate vaccines works not only as an immune stimulator to polysaccharide, but also as an immunogen; with the latter generally not considered as a measured outcome in real world. Here, we probed the potential of a conjugate vaccine platform to induce enhanced immunogenicity of a truncated rotavirus spike protein ΔVP8*. ΔVP8* was covalently conjugated to Vi capsular polysaccharide (Vi) of Salmonella Typhi to develop a bivalent vaccine, termed Vi-ΔVP8*. Our results demonstrated that the Vi-ΔVP8* vaccine can induce specific immune responses against both antigens in immunized mice. The conjugate vaccine elicits high antibody titers and functional antibodies against S. Typhi and Rotavirus (RV) when compared to immunization with a single antigen. Together, these results indicate that Vi-ΔVP8* is a potent and immunogenic vaccine candidate, thus strengthening the potential of conjugate vaccine platform with enhanced immune responses to carrier protein, including ΔVP8*.

Multicenter, double-blind, placebo-controlled trial of seviprotimut-L polyvalent melanoma vaccine in patients with post-resection melanoma at high risk of recurrence.

BACKGROUND: Most patients with advanced melanomas relapse after checkpoint blockade therapy. Thus, immunotherapies are needed that can be applied safely early, in the adjuvant setting. Seviprotimut-L is a vaccine containing human melanoma antigens, plus alum. To assess the efficacy of seviprotimut-L, the Melanoma Antigen Vaccine Immunotherapy Study (MAVIS) was initiated as a three-part multicenter, double-blind, placebo-controlled phase III trial. Results from part B1 are reported here. METHODS: Patients with AJCC V.7 stage IIB-III cutaneous melanoma after resection were randomized 2:1, with stage stratification (IIB/C, IIIA, IIIB/C), to seviprotimut-L 40 mcg or placebo. Recurrence-free survival (RFS) was the primary endpoint. For an hypothesized HR of 0.625, one-sided alpha of 0.10, and power 80%, target enrollment was 325 patients. RESULTS: For randomized patients (n=347), arms were well-balanced, and treatment-emergent adverse events were similar for seviprotimut-L and placebo. For the primary intent-to-treat endpoint of RFS, the estimated HR was 0.881 (95% CI: 0.629 to 1.233), with stratified logrank p=0.46. However, estimated HRs were not uniform over the stage randomized strata, with HRs (95% CIs) for stages IIB/IIC, IIIA, IIIB/IIIC of 0.67 (95% CI: 0.37 to 1.19), 0.72 (95% CI: 0.35 to 1.50), and 1.19 (95% CI: 0.72 to 1.97), respectively. In the stage IIB/IIC stratum, the effect on RFS was greatest for patients <60 years old (HR=0.324 (95% CI: 0.121 to 0.864)) and those with ulcerated primary melanomas (HR=0.493 (95% CI: 0.255 to 0.952)). CONCLUSIONS: Seviprotimut-L is very well tolerated. Exploratory efficacy model estimation supports further study in stage IIB/IIC patients, especially younger patients and those with ulcerated melanomas. TRIAL REGISTRATION NUMBER: NCT01546571.

Identification of Polyvalent Vaccine Candidates From Extracellular Secretory Proteins in Vibrio alginolyticus.

Bacterial infections cause huge losses in aquaculture and a wide range of health issues in humans. A vaccine is the most economical, efficient, and environment-friendly agent for protecting hosts against bacterial infections. This study aimed to identify broad, cross-protective antigens from the extracellular secretory proteome of the marine bacterium Vibrio alginolyticus. Of the 69 predicted extracellular secretory proteins in its genome, 16 were randomly selected for gene cloning to construct DNA vaccines, which were used to immunize zebrafish (Danio rerio). The innate immune response genes were also investigated. Among the 16 DNA vaccines, 3 (AT730_21605, AT730_22220, and AT730_22910) were protective against V. alginolyticus infection with 47-66.7% increased survival compared to the control, while other vaccines had lower or no protective effects. Furthermore, AT730_22220, AT730_22910, and AT730_21605 also exhibited cross-immune protective effects against Pseudomonas fluorescens and/or Aeromonas hydrophila infection. Mechanisms for cross-protective ability was explored based on conserved epitopes, innate immune responses, and antibody neutralizing ability. These results indicate that AT730_21605, AT730_22220, and AT730_22910 are potential polyvalent vaccine candidates against bacterial infections. Additionally, our results suggest that the extracellular secretory proteome is an antigen pool that can be used for the identification of cross-protective immunogens.

Combined vaccine-immune-checkpoint inhibition constitutes a promising strategy for treatment of dMMR tumors.

BACKGROUND: Mlh1-knock-out-driven mismatch-repair-deficient (dMMR) tumors can be targeted immunologically. By applying therapeutic tumor vaccination, tumor growth is delayed but escape mechanisms evolve, including upregulation of immune-checkpoint molecules (LAG-3, PD-L1). To counteract immune escape, we investigated the therapeutic activity of a combined tumor vaccine-immune-checkpoint inhibitor therapy using α-PD-L1. DESIGN: In this trial, Mlh1-knock-out mice with established gastrointestinal tumors received single or thrice injections of α-PD-L1 monoclonal antibody clone 6E11 (2.5 mg/kg bw, q2w, i.v.) either alone or in combination with the vaccine. Longitudinal flow cytometry and PET/CT imaging studies were followed by ex vivo functional immunological and gene expression assays. RESULTS: 6E11 monotherapy slightly increased median overall survival (mOS: 6.0 weeks vs. control 4.0 weeks). Increasing the number of injections (n = 3) improved therapy outcome (mOS: 9.2 weeks) and was significantly boosted by combining 6E11 with the vaccine (mOS: 19.4 weeks vs. 10.2 weeks vaccine monotherapy). Accompanying PET/CT imaging confirmed treatment-induced tumor growth control, with the strongest inhibition in the combination group. Three mice (30%) achieved a complete remission and showed long-term survival. Decreased levels of circulating splenic and intratumoral myeloid-derived suppressor cells (MDSC) and decreased numbers of immune-checkpoint-expressing splenic T cells (LAG-3, CTLA-4) accompanied therapeutic effects. Gene expression and protein analysis of residual tumors revealed downregulation of PI3K/Akt/Wnt-and TGF-signaling, leading to T cell infiltration, reduced numbers of macrophages, neutrophils and MDSC. CONCLUSIONS: By successful uncoupling of the PD-1/PD-L1 axis, we provide further evidence for the safe and successful application of immunotherapies to combat dMMR-driven malignancies that warrants further investigation.

Identification and application of T3SS translocation signal in Edwardsiella piscicida attenuated carrier as a bivalent vaccine.

Type III secretion system (T3SS)-dependent translocation has been used to deliver heterologous antigens by vaccine carriers into host cells. In this research, we identified the translocation signal of Edwardsiella piscicida T3SS effector EseG and constructed an antibiotic resistance-free balanced-lethal system as attenuated vaccine carrier to present antigens by T3SS. Edwardsiella piscicida LSE40 asd gene deletion mutant was constructed and complemented with pYA3342 harbouring the asd (aspartate ß-semialdehyde dehydrogenase) gene from Salmonella. Fusion proteins composed of EseG N-terminal 1-108 amino acids and the TEM1-ß-lactamase reporter were inserted in plasmid pYA3342. The fusion protein could secrete into the cell culture, translocate into HeLa cells, and localize in the membrane fraction. Then, the double gene deletion mutant LSE40ΔasdΔpurA was constructed as an attenuated vaccine carrier, and Aeromonas hydrophila GapA (glyceraldehyde-3-phosphate dehydrogenase) was fused with the translocation signal, instead of the TEM1-ß-lactamase reporter. The bivalent vaccine could protect blue gourami (Trichogaster trichopterus) against E. piscicida and A. hydrophila, with the relative per cent survival of 80.77% and 63.83%, respectively. These results indicated that EseG N-terminal 1-108 amino acid peptide was the translocation signal of E. piscicida T3SS, which could be used to construct bivalent vaccines based on an attenuated E. piscicida carrier.

Efficacy of a multivalent vaccine against Fasciola hepatica infection in sheep.

In this work we report the protection found in a vaccination trial performed in sheep with two different vaccines composed each one by a cocktail of antigens (rCL1, rPrx, rHDM and rLAP) formulated in two different adjuvants (Montanide ISA 61 VG (G1) and Alhydrogel®(G2)). The parameters of protection tested were fluke burden, faecal egg count and evaluation of hepatic lesions. In vaccinated group 1 we found a significant decrease in fluke burden in comparison to both unimmunised and infected control group (37.2%; p = 0.002) and to vaccinated group 2 (Alhydrogel®) (27.08%; p = 0.016). The lower fluke burden found in G1 was accompanied by a decrease in egg output of 28.71% in comparison with the infected control group. Additionally, gross hepatic lesions found in vaccine 1 group showed a significant decrease (p = 0.03) in comparison with unimmunised-infected group. The serological study showed the highest level for both IgG1 and IgG2 in animals from group 1. All these data support the hypothesis of protection found in vaccine 1 group.

A bivalent antihypertensive vaccine targeting L-type calcium channels and angiotensin AT1 receptors.

BACKGROUND AND PURPOSE: Hypertension has been the leading preventable cause of premature death worldwide. The aim of this study was to design a more efficient vaccine against novel targets for the treatment of hypertension. EXPERIMENTAL APPROACH: The epitope CE12, derived from the human L-type calcium channel (CaV 1.2), was designed and conjugated with Qß bacteriophage virus-like particles to test the efficacy in hypertensive animals. Further, the hepatitis B core antigen (HBcAg)-CE12-CQ10 vaccine, a bivalent vaccine based on HBcAg virus-like particles and targeting both human angiotensin AT1 receptors and CaV 1.2 channels, was developed and evaluated in hypertensive rodents. KEY RESULTS: The Qß-CE12 vaccine effectively decreased the BP in hypertensive rodents. A monoclonal antibody against CE12 specifically bound to L-type calcium channels and inhibited channel activity. Injection with monoclonal antibody against CE12 effectively reduced the BP in angiotensin II-induced hypertensive mice. The HBcAg-CE12-CQ10 vaccine showed antihypertensive effects in hypertensive mice and relatively superior antihypertensive effects in spontaneously hypertensive rats and ameliorated L-NAME-induced renal injury. In addition, no obvious immune-mediated damage or electrophysiological adverse effects were detected. CONCLUSION AND IMPLICATIONS: Immunotherapy against both AT1 receptors and CaV 1.2 channels decreased the BP in hypertensive rodents effectively and provided protection against hypertensive target organ damage without obvious feedback activation of renin-angiotensin system or induction of dominant antibodies against the carrier protein. Thus, the HBcAg-CE12-CQ10 vaccine may provide a novel and promising therapeutic approach for hypertension.

Hexavalent Vaccines in India: Current Status.

Hexavalent vaccines containing diphtheria, tetanus, pertussis, Haemophilus influenzae type b, poliomyelitis, and hepatitis B virus antigens have the potential to be used for the primary series in India (6, 10, 14 weeks of age) and the toddler booster dose. Three hexavalent vaccines are available in India: DTwP-Hib/HepB-IPV (wP-hexa), DTaP-IPV-HB-PRP~T(2aP-hexa), and DTaP-HBV-IPV/Hib (3aP-hexa). In the three published phase-3 Indian studies, pertussis 'vaccine response' rates 1 month after a 6-10-14-week primary series were 68.4-75.7% for wP-hexa, 93.8-99.3% for 2aP-hexa, and 97.0-100% for 3aP-hexa; seroprotection rates for the other five antigens were 88.2-100%, 49.6-100%, and 98.6-100%, respectively. Studies outside India show: good immunogenicity/safety after boosting dosing; immune persistence to age 4.5 years (2aP-hexa), 7-9 years (3aP-hexa) (all antigens), and 9-10 and 14-15 years, respectively (hepatitis B); and successful co-administration with other vaccines. Hexavalent vaccines could reduce the number of injections, simplify vaccination schedules, and improve compliance.

DTaP-IPV-HepB-Hib Vaccine (Hexyon®): An Updated Review of its Use in Primary and Booster Vaccination.

Hexyon® is a fully-liquid, ready-to-use, hexavalent vaccine approved in the EU since 2013 for primary and booster vaccination in infants and toddlers from age 6 weeks against diphtheria, tetanus, pertussis, hepatitis B (HB), poliomyelitis, and invasive diseases caused by Haemophilus influenzae type b (Hib). While the source of HB antigen in Hexyon® is different from other vaccines, the rest of its valences have been extensively used in other approved vaccines. Hexyon® is highly immunogenic for all its component toxoids/antigens when used as primary and booster vaccine in infants and toddlers, irrespective of vaccination schedule. It provides durable protection against hepatitis B. Hexyon® can be used for a mixed primary series of hexavalent-pentavalent-hexavalent vaccines or as a booster in infants primed with Infanrix hexa™ or pentavalent (whole-cell or acellular pertussis) vaccines. Coadministration of Hexyon® with other common childhood vaccines did not affect immune response to any vaccines. Hexyon® has a good reactogenicity/safety profile. The immunogenicity and safety profile of Hexyon® was similar to that of several approved vaccines, including Infanrix hexa™. However, Hexyon® offers the convenience of full-liquid, ready-to-use formulation, which may minimize vaccination errors and preparation time. Thus, Hexyon® is a convenient, useful option for vaccination against childhood diseases caused by six major pathogens.

Combination Measles-Mumps-Rubella-Varicella Vaccine in Healthy Children: A Systematic Review and Meta-analysis of Immunogenicity and Safety.

A combined measles-mumps-rubella-varicella (MMRV) vaccine is expected to facilitate universal immunization against these 4 diseases. This study was undertaken to synthesize current research findings of the immunogenicity and safety of MMRV in healthy children.We searched PubMed, Embase, BIOSIS Previews, Web of Science, Cochrane Library, and other databases through September 9, 2014. Eligible randomized controlled trials (RCTs) were selected and collected independently by 2 reviewers. Meta-analysis was conducted using Stata 12.0 and RevMan 5.3.Twenty-four RCTs were included in qualitative synthesis. Nineteen RCTs compared single MMRV dose with measles-mumps-rubella vaccine with or without varicella vaccine (MMR + V/MMR). Similar seroconversion rates of these 4 viruses were found between comparison groups. There were comparable geometric mean titers (GMTs) against mumps and varicella viruses between MMRV group and MMR + V/MMR group. MMRV group achieved enhanced immune response to measles component, with GMT ratio of 1.66 (95% confidence interval [CI] 1.48, 1.86; P < 0.001) for MMRV versus MMR and 1.62 (95% CI 1.51, 1.70; P < 0.001) for MMRV versus MMR + V. Meanwhile, immune response to rubella component in MMRV group was slightly reduced, GMT ratios were 0.81 (95% CI 0.78, 0.85; P < 0.001) and 0.79 (95% CI 0.76, 0.83; P < 0.001), respectively. Well tolerated safety profiles were demonstrated except higher incidence of fever (relative risks 1.12-1.60) and measles/rubella-like rash (relative risks 1.44-1.45) in MMRV groups.MMRV had comparable immunogenicity and overall safety profiles to MMR + V/MMR in healthy children based on current evidence.

Effects of different vaccine combinations against Mycoplasma gallisepticum on blood characteristics in commercial layer chickens.

Mycoplasma gallisepticum (MG) is a major and economically significant pathogen of avian species. When administered before lay, F-strain MG (FMG) can reduce egg production during lay, but the ts-11 strain of MG (ts11MG) does not exert this effect. Two trials were conducted to determine the effects of pre-lay vaccinations of ts11MG, MG-Bacterin (MGBac), or their combination, in conjunction with an FMG challenge overlay after peak production on the blood characteristics of commercial layers. In each trial, 160 mycoplasma-free Hy-Line W-36 layers were housed in negative-pressure biological isolation units (4 units per treatment, 10 birds per unit) from 9 through 52 wk of age (woa). The following vaccination treatments were administered at 10 woa: 1) Control (no vaccinations); 2) MGBac; 3) ts11MG; and 4) ts11MG and MGBac combination (ts11MG+MGBac). At 45 woa, half of the birds were challenged with a laboratory stock of high-passage FMG. Parameters measured in both trials were whole-blood hematocrit and serum concentrations of cholesterol (SCHOL), triglycerides, calcium, and total protein (STP). An age×treatment interaction (P=0.04) was observed for STP between 23 and 43 woa. The STP concentration in the ts11MG and ts11MG+MGBac groups was higher at 33 woa, but was lower at 43 woa, in comparison to the Control group. Also, at 38 woa, the STP of the ts11MG+MGBac group was higher than that of the MGBac group. Although use of the ts11MG vaccine alone or in combination with MGBac may influence circulating STP concentrations when administered before lay, it remains effective in protecting layers against the adverse effect of a post-peak challenge of FMG on egg production, as was observed in a previous companion study.

Immunological evaluation of Vibrio alginolyticus, Vibrio harveyi, Vibrio vulnificus and infectious spleen and kidney necrosis virus (ISKNV) combined-vaccine efficacy in Epinephelus coioides.

Combined vaccines are immunological products intended for immunization against multifactorial infectious diseases caused by different types or variants of pathogens. In this study, the effectiveness of Vibrio alginolyticus (Va), Vibrio harveyi (Vh), Vibrio vulnificus (Vv) and infectious spleen and kidney necrosis virus (ISKNV), an iridovirus, combined-vaccine (Vibrio and ISKNV combined vaccines, VICV), Va+Vh+Vv inactive vaccine (VIV) and ISKNV whole cell inactive vaccine (IWCIV) in Epinephelus coioides were evaluated using various immunological parameters including antibody titer, serum lysozyme activity (LA), respiratory burst (RB) activity, bactericidal activity (BA) and relative percentage survival (RPS). E. coioides immunized with VICV and challenged with Va+Vh+Vv+ISKNV had an RPS of 80%. The RPS was 73.3% in E. coioides immunized with VIV and challenged with Va+Vh+Vv. E. coioides immunized with IWCIV and challenged with ISKNV had an RPS of 69.6%. Serum LA in the vaccinated group was significantly higher than the control group on days 21 and 28 post-vaccination (P<0.01). The RB activity of head kidney cells in the vaccinated group was significantly higher (P<0.01) compared to that in the control group. However, RB activity of spleen cells in the vaccinated group and the control group were not significantly different (P>0.05). After immunization with VICV, BA values of blood leucocytes and head kidney cells increased significantly more than spleen cells. BA value of blood leucocytes was higher than that in head kidney cells. There were distinct difference between BA values in head kidney cells and in spleen cells (P<0.05) as well as between BA value of blood leucocytes and head kidney cells (P<0.01). E. coioides vaccinated with VICV have significantly higher antibody levels than control groupers (P<0.01). Our study suggests that the VICV candidate can effectively protect groupers against multiple bacterial and viral pathogens.

Glioma immunotherapy with combined autologous tumor cell and endothelial cell vaccine in vivo.

Combined vaccines containing GL261 murine glioma cells and F-2 murine endothelial cells fixed with glutaraldehyde-phosphate buffered saline were injected into the intradermal tissue of the tail base of C57BL/6 mice. After the vaccination, GL261 cells were injected subcutaneously into the left flank of the mice. Vaccination with fixed F-2 cells induced the development of relatively high amounts of interferon-gamma-releasing cells after in vitro re-stimulation with vascular endothelial growth factor-receptor 2 peptide. Tumor growth was inhibited after preventive use of the combined vaccine, prepared from GL261 and F-2 cells. Tumor specimens obtained from the combined vaccine group in a therapeutic experiment showed significantly decreased vessel count. Glioma immunotherapy with a combined vaccine prepared from tumor cells and endothelial cells might represent a new clinical strategy, as such combinations may theoretically affect both high-grade glioma cells and their environment.

Meningococcal quadrivalent (serogroups A, C, w135, and y) conjugate vaccine (Menveo): in adolescents and adults.

Menveo is a quadrivalent meningococcal polysaccharide conjugate vaccine containing the four Neisseria meningitidis capsular polysaccharides, A, C, W135, and Y, each conjugated to the mutant diphtheria toxin, known as crossreactive material 197 (CRM(197)). Administration of a single dose of the Menveo vaccine elicited a strong immune response against all four vaccine serogroups in adolescents and adults in randomized, single- or multicenter, phase II or III trials. In adolescents, Menveo was generally more immunogenic against vaccine serogroups than the polysaccharide conjugate vaccine Menactra or the unconjugated polysaccharide vaccine Menomune, in terms of seroresponse and/or seroprotection rates and geometric mean titers (GMTs) 1 month post-vaccination in two phase II or III studies. In two phase III trials in adults aged 19-55 years, the immunogenicity of Menveo was generally noninferior or superior to that of Menactra against all four vaccine serogroups, with regard to seroresponse/seroprotection rates, and GMTs 1 month after vaccination. Moreover, an exploratory arm of one of these studies suggested Menveo was at least as immunogenic as Menomune in adults aged 56-65 years. Longer term, the immunogenicity of Menveo persisted for 12-22 months post-vaccination in the adolescent studies, with the vaccine generally remaining at least as immunogenic as Menactra or Menomune. Coadministration of Menveo with a combined tetanus, reduced diphtheria, and acellular pertussis (Tdap) vaccine or Tdap and human papillomavirus vaccines generally did not affect the immunogenicity of these vaccines in adolescents and young adults in two additional randomized, single- or multicenter, phase III studies. The tolerability profile of Menveo was generally similar to that of the comparator vaccines Menactra or Menomune in adults and adolescents, and few Menveo recipients experienced serious adverse events within 30 days or 6 months post-vaccination.

Spotlight on DTPa-HBV-IPV/Hib Vaccine (Infanrix hexa).

Infanrix hexa, administered intramuscularly, is a diphtheria, tetanus, acellular pertussis, hepatitis B (HBV), inactivated poliomyelitis and Haemophilus influenzae type b (Hib) conjugate vaccine, indicated for primary and booster vaccination of infants. Infanrix hexa should be administered as a two- or three-dose primary vaccination course in infants aged < or =6 months, followed by booster vaccination between 11 and 18 months of age, with an interval of at least 6 months between the last dose of primary vaccination and the booster dose. This spotlight reviews the immunogenicity and protective effectiveness, as well as the reactogenicity and safety of Infanrix hexa. Infanrix hexa as primary and booster vaccination was safe and highly immunogenic for all its component toxoids/antigens in infants aged <2 years, regardless of vaccination schedules. Its immunogenicity and safety profiles were generally similar to those of currently available vaccines, the diphtheria, tetanus and acellular pertussis-based pentavalent vaccines plus monovalent HBV or Hib vaccines. In large clinical studies, Infanrix hexa elicited a strong immune response against vaccine toxoids/antigens, as indicated by high seroprotection/seropositivity/vaccine response rates and geometric mean titers. Moreover, antibodies against vaccine toxoids/antigens persisted for up to a mean of approximately 6 years after booster vaccination, and the vaccine induced long-term immune memory against hepatitis B surface antigen and Hib antigen. A strong immune response against Infanrix hexa toxoids/antigens after primary vaccination was also induced in infants who had received a dose of HBV vaccine at birth and in pre-term infants, although the response in the latter group was somewhat lower than that in full-term infants. In addition, when coadministered with other childhood vaccines, the immunogenicity of Infanrix hexa or that of the concomitantly administered vaccine was generally not altered. Hexavalent vaccines, including Infanrix hexa, were protective against invasive Hib disease; Infanrix hexa is also expected to be protective against pertussis. Most solicited local and general symptoms with Infanrix hexa were mild to moderate in intensity and the vaccine was associated with few unsolicited adverse events. Available clinical data from more than 10 years' experience with the vaccine suggest that Infanrix hexa as primary and booster vaccination is a safe and useful option for providing protection against the common childhood diseases of diphtheria, tetanus, poliomyelitis, pertussis, hepatitis B and invasive Hib disease.

Management of end-stage liver disease in chronic hepatitis B.

The consequences of chronic hepatitis B virus infection include hepatocellular carcinoma and liver cirrhosis. Effective antiviral therapy in patients with hepatitis B with advanced liver disease with viral suppression and sustained HBeAg seroconversion (where applicable) may abort hepatic decompensation, diminish hepatocellular risk, and reduce the risk of viral recurrence after transplantation. Overt hepatic decompensation is an indication for referral to a transplant center.

Combination of protein and viral vaccines induces potent cellular and humoral immune responses and enhanced protection from murine malaria challenge.

The search for an efficacious vaccine against malaria is ongoing, and it is now widely believed that to confer protection a vaccine must induce very strong cellular and humoral immunity concurrently. We studied the immune response in mice immunized with the recombinant viral vaccines fowlpox strain FP9 and modified virus Ankara (MVA), a protein vaccine (CV-1866), or a combination of the two; all vaccines express parts of the same preerythrocytic malaria antigen, the Plasmodium berghei circumsporozoite protein (CSP). Mice were then challenged with P. berghei sporozoites to determine the protective efficacies of different vaccine regimens. Two immunizations with the protein vaccine CV-1866, based on the hepatitis B core antigen particle, induced strong humoral immunity to the repeat region of CSP that was weakly protective against sporozoite challenge. Prime-boost with the viral vector vaccines, FP9 followed by MVA, induced strong T-cell immunity to the CD8+ epitope Pb9 and partially protected animals from challenge. Physically mixing CV-1866 with FP9 or MVA and then immunizing with the resultant combinations in a prime-boost regimen induced both cellular and humoral immunity and afforded substantially higher levels of protection (combination, 90%) than either vaccine alone (CV-1866, 12%; FP9/MVA, 37%). For diseases such as malaria in which different potent immune responses are required to protect against different stages, using combinations of partially effective vaccines may offer a more rapid route to achieving deployable levels of efficacy than individual vaccine strategies.