RESUMO
Glycoconjugate vaccines are based on chemical conjugation of pathogen-associated carbohydrates with immunogenic carrier proteins and are considered a very cost-effective way to prevent infections. Most of the licensed glycoconjugate vaccines are composed of saccharide antigens extracted from bacterial sources. However, synthetic oligosaccharide antigens have become a promising alternative to natural polysaccharides with the advantage of being well-defined structures providing homogeneous conjugates. Haemophilus influenzae (Hi) is responsible for a number of severe diseases. In recent years, an increasing rate of invasive infections caused by Hi serotype a (Hia) raised some concern, because no vaccine targeting Hia is currently available. The capsular polysaccharide (CPS) of Hia is constituted by phosphodiester-linked 4-ß-d-glucose-(1â4)-d-ribitol-5-(PO4â) repeating units and is the antigen for protein-conjugated polysaccharide vaccines. To investigate the antigenic potential of the CPS from Hia, we synthesized related saccharide fragments containing up to five repeating units. Following the synthetic optimization of the needed disaccharide building blocks, they were assembled using the phosphoramidite approach for the installation of the phosphodiester linkages. The resulting CPS-based Hia oligomers were conjugated to CRM197 carrier protein and evaluated inâ vivo for their immunogenic potential, showing that all glycoconjugates were capable of raising antibodies recognizing Hia synthetic fragments.
Assuntos
Glicoconjugados , Haemophilus influenzae , Glicoconjugados/química , Glicoconjugados/imunologia , Glicoconjugados/síntese química , Haemophilus influenzae/imunologia , Haemophilus influenzae/química , Animais , Vacinas Conjugadas/química , Vacinas Conjugadas/imunologia , Camundongos , Vacinas Anti-Haemophilus/imunologia , Vacinas Anti-Haemophilus/química , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/química , Infecções por Haemophilus/prevenção & controle , Infecções por Haemophilus/imunologiaRESUMO
The presence of lactose as a stabilizer in Haemophilus influenzae type b (Hib) conjugate vaccine is a challenge for chromatographic resolution of its total and free poly ribosyl ribitol phosphate (PRP) content. Sample pretreatment using ultrafiltration was performed and had removed ≥95% of lactose in shorter time compared to the conventional dialysis process. Separation of free unconjugated PRP was performed using solid-phase extraction C4 cartridges. Hib conjugate vaccine was then analyzed for determination of total and free PRP, using two validated techniques: high performance anion exchange chromatography with pulsed amperometry (HPAEC-PAD) for ribitol determination and a colorimetric assay for phosphorus determination. Lactose removal had enabled a rapid chromatographic assay via fast depolymerization of PRP using high temperature treatment. Modifying the burning process in the colorimetric assay reduced the analysis time significantly compared to the pharmacopoeial method. Linearity was obtained over the range of 0.10-10.0 µg mL-1 for the HPAEC method and in the range of 1.0-8.0 µg mL-1 for the colorimetric one. Stability of Hib conjugate vaccine was investigated. The HPAEC results revealed about a 35% increase in free PRP content after storage under stressed conditions (moisture and temperature). The proposed methods offered a reliable and economic platform for assessing the immunogenicity, efficacy and stability of Hib conjugate vaccine containing lactose for the biopharmaceutical industry.
Assuntos
Vacinas Anti-Haemophilus , Haemophilus influenzae tipo b , Ânions , Cromatografia , Colorimetria , Vacinas Anti-Haemophilus/química , Haemophilus influenzae tipo b/química , Lactose , Fosfatos , Fósforo , Polissacarídeos/análise , Ribitol , Vacinas Conjugadas/químicaRESUMO
Molecular size distribution of Haemophilus influenzae type b (Hib) conjugate vaccine is an important indicator for its immunogenicity and stability. Molecular size distribution was evaluated by High-Performance Protein Chromatography on Sepharose CL-4B column, and fractions were pooled. The use of high flow rate, incorporation of a calibration standard with the injected buffer and pooling method yielded a superior assay compared to conventional pharmacopeial method. The pools were analyzed for determination of distribution coefficient (KD) of 0.2 and 0.5 using two validated techniques: High Performance Anion Exchange Chromatography with pulsed amperometric detection (HPAEC-PAD) for ribitol determination and an optimized colorimetric assay for phosphorus determination. Linearity was achieved over range of 0.10-10.0 µg/mL and 1.0-8.0 µg/mL with LOD of 0.03 and 0.28 µg/mL for HPAEC and colorimetric assays, respectively. The developed assays were successfully applied in quality control monitoring of Hib conjugate vaccine. The optimized colorimetric method had shortened the analysis time to 25 min compared to 3.5 h for the European pharmacopeial assay by modifying the burning process. HPAEC stability results revealed 40% decrease in MSD after stressed storage conditions. The proposed assays offer a reliable and economic platform for monitoring the quality attributes of Hib for biopharma industry.
Assuntos
Vacinas Anti-Haemophilus , Lactose , Colorimetria , Vacinas Anti-Haemophilus/análise , Vacinas Anti-Haemophilus/química , Haemophilus influenzae , Vacinas ConjugadasAssuntos
Clorexidina/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Meningocócicas/efeitos adversos , Clorexidina/análise , Dermatite Alérgica de Contato/patologia , Vacina contra Difteria, Tétano e Coqueluche/química , Desinfetantes/efeitos adversos , Desinfetantes/análise , Vacinas Anti-Haemophilus/química , Humanos , Lactente , Masculino , Vacinas Meningocócicas/química , Vacinas Combinadas/efeitos adversosRESUMO
CTAB and DOC are used as reagents in the purification of Hib polysaccharide. Polysaccharide is purified by precipitation with CTAB from fermented broth followed by solvent extraction and DOC is used to remove the protein impurities. The reagents used in the purification process should be removed from the product as per regulatory requirements. These two residual reagents can be easily identified and quantified in purified Haemophilus influenzae type b polysaccharide by NMR. The LOD of these residual reagents is 0.1% (10 µg/mL) and LOQ is 0.5% (50 µg/mL) with respect to polysaccharide determined from the spectrum. The absence of the peaks corresponding to CTAB and DOC in the NMR spectrum of purified polysaccharide confirms either they are absent or present at less than 0.1%. The present study provides supporting data from the regulatory viewpoint, which can help in circumventing the time-consuming studies for the vaccine manufacturers to develop different analytical methods for identification and quantification of CTAB and DOC as per regulatory requirements.
Assuntos
Cetrimônio/análise , Ácido Desoxicólico/análise , Vacinas Anti-Haemophilus , Polissacarídeos Bacterianos/química , Antígenos de Bactérias/química , Vacinas Anti-Haemophilus/química , Haemophilus influenzae tipo bRESUMO
BACKGROUND: Vaccination against Haemophilus influenzae type b (Hib) is included in routine pediatric immunization schedule in the United States. Previous vaccine shortages have created the need for additional options for Hib vaccination. METHODS: This phase III, randomized, multi-centered study (NCT01000974) evaluated the safety and immunogenicity of a monovalent tetanus toxoid-conjugate Hib vaccine (Hib-TT) compared to a monovalent (Hib-TT control) and a combination Hib-TT vaccine. We hierarchically assessed lot-to-lot consistency of 3 Hib-TT lots and non-inferiority of Hib-TT to Hib-TT control. We co-administered routine pediatric vaccines with Hib-TT vaccines at 2, 4, 6months (primary vaccination) and 15-18months of age (booster vaccination). We recorded adverse events (AEs) for 4 (solicited) and 31days (unsolicited) post-vaccination and serious AEs (SAEs) throughout the study. RESULTS: Of 4009 enrolled children, 3086 completed booster phase. Lot-to-lot consistency was not demonstrated. The study met statistical criteria for non-inferiority of Hib-TT to Hib-TT control in terms of immune responses to Hib and co-administered vaccines' antigens, but not in terms of participants achieving post-primary vaccination anti-PRP levels ≥1µg/mL. Because of the hierarchical nature of the objectives, non-inferiority could not be established. In all groups, 92.5-96.7% and 99.6-100% of participants achieved anti-PRP levels ≥0.15µg/mL, while 78.3-89.8% and 97.9-99.1% had anti-PRP levels ≥1µg/mL, post-primary and post-booster vaccination, respectively. Immune responses to co-administered vaccines and reported incidence of AEs were comparable among groups. We recorded SAEs for 107/2963 (3.6%), 24/520 (4.6%), and 21/520 (4.0%) children post-primary vaccination, and 29/2337 (1.2%), 4/435 (0.9%), and 2/400 (0.5%) children post-booster vaccination with Hib-TT, Hib-TT control and combination Hib-TT vaccine, respectively; 6/5330 (0.1%) SAEs in the Hib-TT groups were considered vaccine-related. CONCLUSION: Hib-TT induced seroprotective antibody concentrations in the majority of participants and was well-tolerated when co-administered with routine pediatric vaccines according to a 3+1 schedule.
Assuntos
Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Anti-Haemophilus/imunologia , Anticorpos Antibacterianos/sangue , Cápsulas Bacterianas/imunologia , Feminino , Infecções por Haemophilus/epidemiologia , Infecções por Haemophilus/imunologia , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/química , Haemophilus influenzae tipo b/imunologia , Humanos , Esquemas de Imunização , Imunização Secundária , Imunogenicidade da Vacina , Lactente , Masculino , Toxoide Tetânico/administração & dosagem , Toxoide Tetânico/efeitos adversos , Toxoide Tetânico/imunologia , Estados Unidos/epidemiologia , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/química , Vacinas Conjugadas/imunologiaRESUMO
AIM: Study safety, reactogenicity and immunologic effectiveness of a national combined vaccine against diphtheria, pertussis (acellular component), tetanus, hepatitis B and Hib-infection during immunization of volunteers aged 18-60 years. MATERIALS AND METHODS: The study was carried out in accordance with ethical standards and requirements, regulated by Helsinki declaration and Good clinical practice (ICHGCP). In a simple non-randomized clinical trial 20 adult volunteers took part, the mean age of those was 46.9 years. RESULTS: Registered: post-vaccination reactions (both local and systemic) were mild and of moderate degree of severity, stopped independently after 2-3 days without administration of drug treatment. Postvaccinal complications were not noted. Parameters of general and biochemical analysis of blood, urine, IgE content in dynamics of immunization were within normal limits. A single administration of aAPDT--HepB+Hib to individuals aged 18-60 years resulted in development of antibodies against all the components of the preparation. Seroconversion factor fluctuated from 6.9 to 53.5: CONCLUSION: The results obtained allow to recommend the vaccine for evaluation of its safety, reactogenicity, immunologic and prophylaxis effectiveness in randomized clinical observation trials in children.
Assuntos
Anticorpos Antibacterianos/biossíntese , Anticorpos Antivirais/biossíntese , Difteria/prevenção & controle , Infecções por Haemophilus/prevenção & controle , Hepatite B/prevenção & controle , Tétano/prevenção & controle , Coqueluche/prevenção & controle , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Difteria/imunologia , Difteria/microbiologia , Vacinas contra Difteria, Tétano e Coqueluche Acelular/administração & dosagem , Vacinas contra Difteria, Tétano e Coqueluche Acelular/química , Vacinas contra Difteria, Tétano e Coqueluche Acelular/imunologia , Feminino , Infecções por Haemophilus/imunologia , Infecções por Haemophilus/microbiologia , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/química , Vacinas Anti-Haemophilus/imunologia , Hepatite B/imunologia , Hepatite B/virologia , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/química , Vacinas contra Hepatite B/imunologia , Humanos , Imunidade Humoral/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Tétano/imunologia , Tétano/microbiologia , Vacinação , Vacinas de Subunidades Antigênicas , Coqueluche/imunologia , Coqueluche/microbiologiaRESUMO
Haemophilus influenzae type b (Hib) causes many severe diseases, including epiglottitis, pneumonia, sepsis, and meningitis. In developed countries, the annual incidence of meningitis caused by bacteria is approximately 5-10 cases per population of 100,000. The Hib conjugate vaccine is considered protective and safe. Adjuvants, molecules that can enhance and/or regulate the fundamental immunogenicity of an antigen, comprise a wide range of diverse compounds. While earlier developments of adjuvants created effective products, there is still a need to create new generations, rationally designed based on recent discoveries in immunology, mainly in innate immunity. Many factors may play a role in the immunogenicity of Hib conjugate vaccines, such as the polysaccharides and proteins carrier used in vaccine construction, as well as the method of conjugation. A Hib conjugate vaccine has been constructed via chemical synthesis of a Hib saccharide antigen. Two models of carbohydrate-protein conjugate have been established, the single ended model (terminal amination-single method) and cross-linked lattice matrix (dual amination method). Increased knowledge in the fields of immunology, molecular biology, glycobiology, glycoimmunology, and the biology of infectious microorganisms has led to a dramatic increase in vaccine efficacy.
Assuntos
Antígenos de Bactérias/imunologia , Vacinas Anti-Haemophilus/administração & dosagem , Haemophilus influenzae tipo b/imunologia , Meningite por Haemophilus/prevenção & controle , Polissacarídeos Bacterianos/imunologia , Vacinação , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/química , Antígenos de Bactérias/química , Cápsulas Bacterianas/química , Cápsulas Bacterianas/imunologia , Desenho de Fármacos , Vacinas Anti-Haemophilus/química , Vacinas Anti-Haemophilus/imunologia , Haemophilus influenzae tipo b/química , Humanos , Imunidade Inata/efeitos dos fármacos , Imunoconjugados/administração & dosagem , Imunoconjugados/química , Imunoconjugados/imunologia , Meningite por Haemophilus/imunologia , Meningite por Haemophilus/microbiologia , Polissacarídeos Bacterianos/química , Vacinas ConjugadasRESUMO
In this report we present the results of a collaborative study for the preparation and calibration of a replacement International Standard (IS) for Haemophilus influenzae type b polysaccharide (polyribosyl ribitol phosphate; 5-d-ribitol-(1 â 1)-ß-d-ribose-3-phosphate; PRP). Two candidate preparations were evaluated. Thirteen laboratories from 9 different countries participated in the collaborative study to assess the suitability and determine the PRP content of two candidate standards. On the basis of the results from this study, Candidate 2 (NIBSC code 12/306) has been established as the 2nd WHO IS for PRP by the Expert Committee of Biological Standards of the World Health Organisation with a content of 4.904 ± 0.185mg/ampoule, as determined by the ribose assays carried out by 11 of the participating laboratories.
Assuntos
Haemophilus influenzae tipo b/química , Polissacarídeos Bacterianos/normas , Polissacarídeos/normas , Organização Mundial da Saúde , Cápsulas Bacterianas/química , Bioensaio/normas , Calibragem , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Vacinas Anti-Haemophilus/química , Vacinas Anti-Haemophilus/normas , Concentração de Íons de Hidrogênio , Cooperação Internacional , Laboratórios/normas , Fósforo/análise , Polissacarídeos/análise , Polissacarídeos Bacterianos/análise , Padrões de Referência , Reprodutibilidade dos Testes , Ribose/análiseRESUMO
Capsular polysaccharide conjugates of Haemophilus influenzae type b (Hib) are important components of several mono- or multi-valent childhood vaccines. However, their access to the most needy people is limited due to their high cost. As a step towards developing a cost effective and more immunogenic Hib conjugate vaccine, we present a method for the preparation of Hib capsular polysaccharide (PRP)-tetanus toxoid (TT) conjugates using optimized PRP chain length and conjugation conditions. Reactive aldehyde groups were introduced into the polysaccharides by controlled periodate oxidation of the native polysaccharide, which were subsequently covalently linked to hydrazide derivatized tetanus toxoid by means of reductive amination. Native polysaccharides were reduced to average 100 or 50kDa polysaccharide and 10kDa oligosaccharides in a controlled manner. Various conjugates were prepared using Hib polysaccharide and oligosaccharide yielding conjugates with polysaccharide to protein ratios in the range of 0.25-0.5 (w/w) and free saccharide levels of less than 10%. Immunization of Sprague Dawley rats with the conjugates elicited specific antibodies to PRP. The low molecular weight PRP-TT conjugates were found to be more immunogenic as compared to their high molecular weight counterparts and the PRP-TT reference vaccine.
Assuntos
Vacinas Anti-Haemophilus/química , Vacinas Anti-Haemophilus/imunologia , Haemophilus influenzae tipo b/imunologia , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Animais , Anticorpos Antibacterianos/sangue , Feminino , Peso Molecular , Ratos Sprague-Dawley , Toxoide Tetânico/química , Toxoide Tetânico/imunologia , Vacinas Conjugadas/química , Vacinas Conjugadas/imunologiaRESUMO
UNLABELLED: The frequency of long-lasting, intensely itching subcutaneous nodules at the injection site for aluminium (Al)-adsorbed vaccines (vaccination granulomas) was investigated in a prospective cohort study comprising 4,758 children who received either a diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b vaccine (Infanrix®, Pentavac®) alone or concomitant with a pneumococcal conjugate (Prevenar). Both vaccines were adsorbed to an Al adjuvant. Altogether 38 children (0.83 %) with itching granulomas were identified, epicutaneously tested for Al sensitisation and followed yearly. Contact allergy to Al was verified in 85 %. The median duration of symptoms was 22 months in those hitherto recovered. The frequency of granulomas induced by Infanrix® was >0.66 % and by Prevenar >0.35 %. The risk for granulomas increased from 0.63 to 1.18 % when a second Al-adsorbed vaccine was added to the schedule. CONCLUSION: Long-lasting itching vaccination granulomas are poorly understood but more frequent than previously known after infant vaccination with commonly used diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b and pneumococcal conjugate vaccines. The risk increases with the number of vaccines given. Most children with itching granulomas become contact allergic to aluminium. Itching vaccination granulomas are benign but may be troublesome and should be recognised early in primary health care to avoid unnecessary investigations, anxiety and mistrust.
Assuntos
Alumínio/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacinas contra Difteria, Tétano e Coqueluche Acelular/efeitos adversos , Granuloma/etiologia , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Pneumocócicas/efeitos adversos , Vacina Antipólio de Vírus Inativado/efeitos adversos , Prurido/etiologia , Adolescente , Criança , Pré-Escolar , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/epidemiologia , Vacina contra Difteria, Tétano e Coqueluche/química , Vacinas contra Difteria, Tétano e Coqueluche Acelular/química , Feminino , Seguimentos , Granuloma/diagnóstico , Granuloma/epidemiologia , Vacinas Anti-Haemophilus/química , Vacina Pneumocócica Conjugada Heptavalente , Humanos , Lactente , Masculino , Vacinas Pneumocócicas/química , Vacina Antipólio de Vírus Inativado/química , Estudos Prospectivos , Prurido/epidemiologia , Risco , Suécia , Vacinas Combinadas/efeitos adversos , Vacinas Combinadas/químicaRESUMO
Current Haemophilus influenzae b conjugate vaccines (Hib), which are made of purified capsular polysaccharide (poly-ribosyl-ribitol-phosphate; PRP) conjugated to a carrier protein, are almost completely evaluated by physico-chemical methods to ensure the integrity and stability of the vaccine and consistency of manufacture of batches. The absence of a potency assay makes the quantification of total PRP content (in SI units) and of % free polysaccharide in final fills or bulk components of Hib vaccines critical release tests for both manufacturers and national control authorities. Here we describe a simple and sensitive Enzyme-Linked Immuno-sorbent Assay (ELISA) which has been developed to quantify total and free PRP content in Hib-TT vaccine alone or when in combination with other vaccines. The assay is robust, specific and highly sensitive.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Vacinas Anti-Haemophilus/química , Polissacarídeos/análise , Toxoide Tetânico/química , Vacinas Combinadas/química , Limite de Detecção , Reprodutibilidade dos TestesRESUMO
A gradient method has been devised for the rapid analysis of alkaline hydrolyzates of Haemophilus influenzae type b (Hib) capsular polysaccharide-based vaccines by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). As compared with published procedures, peak shape and sensitivity were significantly improved with this approach, analysis time was short and there was little interference from impurities. The limits of detection and quantification were established with a purified reference polysaccharide. We propose this method as a practical alternative for the analysis of minute amounts of Hib polysaccharide, which can be lower than with the conventional approaches.
Assuntos
Cápsulas Bacterianas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Haemophilus influenzae tipo b/química , Cápsulas Bacterianas/metabolismo , Vacinas Anti-Haemophilus/química , Haemophilus influenzae tipo b/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Sensibilidade e Especificidade , Acetato de Sódio/química , Hidróxido de Sódio/químicaRESUMO
Formaldehyde is a one-carbon, highly water-soluble aldehyde that is used in certain vaccines to inactivate viruses and to detoxify bacterial toxins. As part of the manufacturing process, some residual formaldehyde can remain behind in vaccines at levels less than or equal to 0.02%. Environmental and occupational exposure, principally by inhalation, is a continuing risk assessment focus for formaldehyde. However, exposure to formaldehyde via vaccine administration is qualitatively and quantitatively different from environmental or occupational settings and calls for a different perspective and approach to risk assessment. As part of a rigorous and ongoing process of evaluating the safety of biological products throughout their lifecycle at the FDA, we performed an assessment of formaldehyde in infant vaccines, in which estimates of the concentrations of formaldehyde in blood and total body water following exposure to formaldehyde-containing vaccines at a single medical visit were compared with endogenous background levels of formaldehyde in a model 2-month-old infant. Formaldehyde levels were estimated using a physiologically-based pharmacokinetic (PBPK) model of formaldehyde disposition following intramuscular (IM) injection. Model results indicated that following a single dose of 200 µg, formaldehyde is essentially completely removed from the site of injection within 30 min. Assuming metabolism at the site of injection only, peak concentrations of formaldehyde in blood/total body water were estimated to be 22 µg/L, which is equivalent to a body burden of 66 µg or <1% of the endogenous level of formaldehyde. Predicted levels in the lymphatics were even lower. Assuming no adverse effects from endogenous formaldehyde, which exists in blood and extravascular water at background concentrations of 0.1 mM, we conclude that residual, exogenously applied formaldehyde continues to be safe following incidental exposures from infant vaccines.
Assuntos
Reagentes de Ligações Cruzadas/farmacocinética , Formaldeído/farmacocinética , Modelos Biológicos , Reagentes de Ligações Cruzadas/administração & dosagem , Reagentes de Ligações Cruzadas/efeitos adversos , Vacina contra Difteria, Tétano e Coqueluche/química , Formaldeído/administração & dosagem , Formaldeído/efeitos adversos , Vacinas Anti-Haemophilus/química , Vacinas contra Hepatite B/química , Humanos , Lactente , Injeções Intramusculares , Vacina Antipólio de Vírus Inativado/química , Medição de RiscoRESUMO
INTRODUCTION: The introduction of injectable vaccines targeting new diseases into childhood immunization programs has resulted in the need for combination vaccines to reduce the number of injections given during early childhood and maintain acceptability of targeting multiple pathogens by vaccination. Currently, there is only one licensed hexavalent combination vaccine which targets diphtheria, polio, tetanus, Haemophilus influenzae type b, hepatitis B and pertussis. A new, fully liquid formulation hexavalent vaccine ( Hexaxim ) has been developed and is currently undergoing licensure for use in childhood immunization programs. AREAS COVERED: Safety and immunogenicity studies of Hexaxim have been undertaken in a diversity of settings, been evaluated with different dosing schedules and in comparison to the other licensed hexavalent vaccine (Infanrix hexa). This review of published journal articles and conference proceeding is focused on the studies in which Hexaxim has been evaluated and which are contributing to its pending licensure. Non-inferiority was demonstrated at the level of proportion of children developing seroprotective titers or showing seroconversion following the primary series of vaccine compared to the same target-antigens included in licensed combination vaccines. Also, Hexaxim was associated with a favorable safety and tolerability profile when administered during the first 6 months of life. Adequate and robust memory responses were elicited following a booster dose in the second year of life. EXPERT OPINION: The development of new hexavalent combination vaccines targeting established pathogens is likely to assist in improving compliance and timeliness of vaccination in infants. These formulations will, however, need to be monitored for medium- and long-term effectiveness amidst growing concern of waning immunity against diseases such as pertussis when using acellular-pertussis vaccine and possibly hepatitis B when using combination vaccines. Nevertheless, the development of such combination vaccines remains necessary to help with the introduction of other new vaccines into an already crowded childhood immunization schedules.
Assuntos
Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/química , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/química , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/química , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacina Antipólio de Vírus Inativado/química , Animais , Química Farmacêutica , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Vacinas Anti-Haemophilus/imunologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Vacinas contra Hepatite B/imunologia , Humanos , Esquemas de Imunização , Vacina Antipólio de Vírus Inativado/imunologia , Vacinação/tendências , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/química , Vacinas Combinadas/imunologiaRESUMO
A 2-year-old girl presented with an intensely itching subcutaneous nodule on the front of a thigh. The nodule persisted for 10 months until it was excised. Subsequent investigation for malignancy and systemic disease showed no pathological findings. The diagnosis, persistent itching vaccination granuloma, was revealed by hazard almost 2 years after the onset of symptoms. Persistent itching subcutaneous nodules at the injection site for aluminium containing vaccines (mostly diphtheria-tetanus-pertussis combination vaccines for primary immunisation of infants) may appear with a long delay after the vaccination (months), cause prolonged itching (years) and are often associated with contact allergy to aluminium. The condition is poorly recognised in Health Care which may lead to prolonged symptoms and unnecessary investigations.
Assuntos
Alumínio/efeitos adversos , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Toxidermias/etiologia , Granuloma/induzido quimicamente , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas contra Hepatite B/efeitos adversos , Prurido/induzido quimicamente , Pré-Escolar , Vacina contra Difteria, Tétano e Coqueluche/química , Toxidermias/cirurgia , Feminino , Granuloma/cirurgia , Vacinas Anti-Haemophilus/química , Vacinas contra Hepatite B/química , Humanos , Coxa da Perna , Fatores de TempoRESUMO
Haemophilus parasuis causes contagious porcine Glässer's disease leading to severe losses in the swine industry. In this study, we established an efficient Escherichia colibased system for the expression of H. parasuis major outer-membrane protein (MOMP) that has been known as a good vaccine candidate against Glässer's disease. Use of an E. coli-derived pelB leader sequence made it possible to produce recombinant MOMP (rMOMP) as the soluble forms without an additional refolding process. Using two different animal models, it was evaluated that the rMOMP was capable of inducing a significant immune response and providing protection against H. parasuis infection.
Assuntos
Proteínas da Membrana Bacteriana Externa/biossíntese , Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/metabolismo , Haemophilus parasuis/metabolismo , Proteínas Recombinantes/biossíntese , Animais , Anticorpos Antibacterianos/imunologia , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Western Blotting , Modelos Animais de Doenças , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Cobaias , Infecções por Haemophilus/imunologia , Vacinas Anti-Haemophilus/química , Vacinas Anti-Haemophilus/genética , Vacinas Anti-Haemophilus/imunologia , Haemophilus parasuis/genética , Haemophilus parasuis/imunologia , Camundongos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Solubilidade , Análise de SobrevidaRESUMO
Quimi-Hib is a conjugate vaccine against Haemophilus influenza type b (Hib) where the Hib antigen is the only one produced by chemical synthesis. NMR has become the alternative of choice for the identity of intermediates during the chemical synthesis of Hib antigen. We explore a rapid quantitative proton magnetic resonance (qHNMR) assay for the determination of N,N-dimethylformamide (DMF) as a residual in one of the critical intermediates. The proposed assay has been shown to be accurate, precise for intermediate precision conditions (relative standard deviation <3% for spectrometer-to-spectrometer variations), specific (no detected interferences), and rugged (percentage difference <3% for day-to-day and spectrometer-to-spectrometer variations). The quantitative NMR assay can replace the common chromatographic methods for monitoring the DMF contents in one crucial step of the synthetic scheme.
Assuntos
Dimetilformamida/análise , Vacinas Anti-Haemophilus/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Prótons , Vacinas Conjugadas/químicaRESUMO
BACKGROUND: A hepatitis B vaccine was manufactured with a modified process (mpHBV) that incorporated double the usual amount of phosphate. Following a study in young adults, the mpHBV was evaluated in infants in a combination hepatitis B and Haemophilus influenzae B vaccine (mpHBV-Hib). METHODS: The mpHBV-Hib was compared with the licensed bivalent HBV-Hib vaccine Comvax™ for immunogenicity and safety. Both vaccines contained 5 µg/0.5 mL of hepatitis B surface antigen (HBsAg) and 7.5 µg/0.5 mL of PRP-OMPC (polyribosylribitol phosphate outer membrane protein complex). A total of 543 infants were randomized 1:1 to receive either vaccine at 2, 4 and 12 months of age. A pneumococcal conjugate vaccine (PCV) was given concomitantly. Immunogenicity was assessed at 1-month post-dose 3. RESULTS: Seroprotection rates [% subjects with anti-hepatitis B surface antigen antibody titers (anti-HBs) ≥10 mIU/mL)] were 100% and 99% for mpHBV-Hib and the licensed control (Comvax™), respectively. Anti-HBs geometric mean titers (GMTs) were 4204 (95% CI, 3411-5182) and 1683 (95% CI, 1350-2099) mIU/mL, respectively. Anti-PRP seroprotection rates (SPR) at ≥0.15 µg/mL and at ≥1.0 µg/mL were 97% and 94%, respectively, for mpHBV-Hib and 96% and 92%, respectively, for the control. Anti-PRP GMTs were 7.1 µg/mL for mpHBV-Hib and 8.0 µg/mL for the control. Reactogenicity of the two vaccines was similar. CONCLUSIONS: The mpHBV in combination with Hib and with co-administered PCV was highly immunogenic. The safety profile of mpHBV-Hib was comparable to the licensed control. Both the control and mpHBV-Hib met acceptability criteria for seroprotection rates to hepatitis B, with higher anti-HBs GMTs noted for mpHBV-Hib.
Assuntos
Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Anti-Haemophilus/imunologia , Vacinas contra Hepatite B/efeitos adversos , Vacinas contra Hepatite B/imunologia , Hepatite B/prevenção & controle , Imunização Secundária/métodos , Vacinação/métodos , Anticorpos Antibacterianos/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Feminino , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/química , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/química , Humanos , Lactente , Masculino , Vacinas Pneumocócicas/administração & dosagem , Polissacarídeos Bacterianos/imunologia , Vacinas Conjugadas/administração & dosagemRESUMO
P6 has been a vaccine candidate for nontypable Haemophilus influenzae (NTHi) based on its location on the outer membrane and immunogenicity. Because P6 is attached to the inner peptidoglycan layer of NTHi, and is putatively surface exposed, it must be a transmembrane protein. We examined the P6 structure using computational modeling, site-directed mutagenesis, and nuclear magnetic resonance spectroscopy. We found that P6 cannot be a transmembrane protein, and therefore may not be surface exposed. We conclude that there may be another protein on the surface of NTHi that has epitopes similar if not identical to P6.