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1.
Proc Natl Acad Sci U S A ; 110(35): 14330-5, 2013 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-23940329

RESUMEN

Protection against influenza is mediated by neutralizing antibodies, and their induction at high and sustained titers is key for successful vaccination. Optimal B cells activation requires delivery of help from CD4(+) T lymphocytes. In lymph nodes and tonsils, T-follicular helper cells have been identified as the T cells subset specialized in helping B lymphocytes, with interleukin-21 (IL-21) and inducible costimulatory molecule (ICOS1) playing a central role for this function. We followed the expansion of antigen-specific IL-21(+) CD4(+) T cells upon influenza vaccination in adults. We show that, after an overnight in vitro stimulation, influenza-specific IL-21(+) CD4(+) T cells can be measured in human blood, accumulate in the CXCR5(-)ICOS1(+) population, and increase in frequency after vaccination. The expansion of influenza-specific ICOS1(+)IL-21(+) CD4(+) T cells associates with and predicts the rise of functionally active antibodies to avian H5N1. We also show that blood-derived CXCR5(-)ICOS1(+) CD4(+) T cells exert helper function in vitro and support the differentiation of influenza specific B cells in an ICOS1- and IL-21-dependent manner. We propose that the expansion of antigen-specific ICOS1(+)IL-21(+) CD4(+) T cells in blood is an early marker of vaccine immunogenicity and an important immune parameter for the evaluation of novel vaccination strategies.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Humanos , Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/sangre , Gripe Humana/prevención & control , Interleucinas , Vacunación
2.
Eur J Immunol ; 43(3): 641-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23238926

RESUMEN

Cross-protection against divergent strains of influenza virus is an objective of various vaccination approaches. B cells cross-neutralizing several influenza A heterosubtypes have been isolated from cultured human memory B cells (MBCs) and plasmablasts early after influenza vaccination or infection. However, a systematic assessment of the frequency of MBCs and plasmablasts in the blood of healthy individuals is lacking. Here, we show that under resting conditions about 45% of human adults never vaccinated nor exposed to avian A/H5N1 influenza have detectable circulating MBCs cross-reacting with H5N1. This proportion rises to 63.3% among subjects with a large pool of MBCs specific for seasonal H1N1 (i.e. frequency ≥1% of total IgG MBCs). Moreover, subjects with high baseline frequencies of H1N1-specific MBCs had an expansion of H5N1-specific MBCs producing H5-neutralizing antibodies already after the first dose of an MF59-adjuvanted H5N1 vaccine. These results suggest that H1N1-specific MBCs contain a subset of cells cross-reacting to H5. We propose that a proportion of human adults have a pool of H5/H1 cross-reactive MBCs that contribute to the rapid rise of the antibody response to divergent influenza strains. This may have implications on vaccination strategies aimed at counteracting future influenza pandemics.


Asunto(s)
Memoria Inmunológica , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Adulto , Animales , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , Reacciones Cruzadas/inmunología , Humanos , Inmunoglobulina G/inmunología , Vacunas contra la Influenza/administración & dosificación
3.
J Infect ; 85(5): 481-491, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36087745

RESUMEN

OBJECTIVES: Invasive meningococcal disease (IMD) is a life-threatening disease that can rapidly progress to death or leave survivors with severe, life-long sequelae. Five meningococcal serogroups (A, B, C, W and Y) account for nearly all IMD. Meningococcal serogroup distribution fluctuates over time across the world and age groups. Here, we consider the potential public health impact of a pentavalent MenABCWY vaccine developed to help further control meningococcal disease and improve immunisation rates. RESULTS: The GSK MenABCWY vaccine combines the antigenic components of MenACWY-CRM (Menveo®) and 4CMenB (Bexsero®), building on a wide body of clinical experience and real-world evidence. Both approved vaccines have acceptable safety profiles, demonstrate immunogenicity, and are broadly used, including in national immunisation programmes in several countries. Since the advent of quadrivalent vaccines, public health in relation to IMD has improved, with a decline in the overall incidence of IMD and an increase in vaccine coverage. CONCLUSION: A pentavalent MenABCWY has the potential to provide further public health benefits through practical, broad IMD protection programmes encompassing serogroups A, B, C, W and Y, and is currently in late-stage development.


Asunto(s)
Infecciones Meningocócicas , Vacunas Meningococicas , Neisseria meningitidis , Humanos , Infecciones Meningocócicas/epidemiología , Infecciones Meningocócicas/prevención & control , Salud Pública , Vacunas Combinadas , Vacunas Conjugadas
4.
Hum Vaccin Immunother ; 18(1): 1981085, 2022 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-34614379

RESUMEN

A fully liquid MenACWY-CRM vaccine presentation has been developed, modifying the meningococcal serogroup A (MenA) component from lyophilized to liquid. The safety and immunogenicity of the liquid presentation at the end of the intended shelf-life (aged for 24 or 30 months) were compared to the licensed lyophilized/liquid presentation. This multicenter, randomized (1:1), observer-blind, phase 2b study (NCT03433482) enrolled adolescents and young adults (age 10-40 years). In part 1, 844 participants received one dose of liquid presentation stored for approximately 24 months or licensed presentation. In part 2, 846 participants received one dose of liquid presentation stored for approximately 30 months or licensed presentation. After storage, the MenA free saccharide (FS) level was approximately 25% and O-acetylation was approximately 45%. The primary objective was to demonstrate non-inferiority of the liquid presentation to licensed presentation, as measured by human serum bactericidal assay (hSBA) geometric mean titers (GMTs) against MenA, 1-month post-vaccination. Immune responses against each vaccine serogroup were similar between groups. Between-group ratios of hSBA GMTs for MenA were 1.21 (part 1) and 1.11 (part 2), with two-sided 95% confidence interval lower limits (0.94 and 0.87, respectively) greater than the prespecified non-inferiority margin (0.5), thus meeting the primary study objective. No safety concerns were identified. Despite reduced O-acetylation of MenA and increased FS content, serogroup-specific immune responses induced by the fully liquid presentation were similar to those induced by the licensed MenACWY-CRM vaccine, with non-inferior anti-MenA responses. The safety profiles of the vaccine presentations were similar.


Asunto(s)
Infecciones Meningocócicas , Vacunas Meningococicas , Neisseria meningitidis , Adolescente , Adulto , Anciano , Anticuerpos Antibacterianos , Niño , Humanos , Infecciones Meningocócicas/prevención & control , Serogrupo , Vacunas Conjugadas , Adulto Joven
5.
Vaccine ; 39(45): 6628-6636, 2021 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-34635373

RESUMEN

BACKGROUND: The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilised MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid formulation in a single vial has been developed to further improve the vaccine presentation. Since the MenA structure is subject to hydrolytic degradation, this study was conducted to compare the immunogenicity and safety of the investigational MenACWY-CRM liquid vaccine with the licensed vaccine. METHODS: In this multicentre, randomised, controlled, observer-blind, phase 2b study, 979 healthy adults were administered a single dose of MenACWY-CRM liquid presentation or the currently licensed MenACWY-CRM vaccine. MenA free saccharide generation was accelerated to approximately 30% in the liquid presentation and MenA polysaccharide O-acetylation was reduced to approximately 40%, according to a controlled procedure. Immunological non-inferiority of the MenACWY-CRM liquid to the licensed vaccine, as measured by human serum bactericidal assay (hSBA) geometric mean titres (GMTs) against MenA 1 month post-vaccination, was the primary study objective. Safety assessment was among the secondary objectives. RESULTS: Immune responses against each serogroup were similar between the two vaccine groups and was non-inferior for MenA. Adjusted hSBA GMTs for MenA were 185.16 and 211.33 for the MenACWY-CRM liquid presentation and currently licensed vaccine presentation, respectively. The between-group ratio of hSBA GMTs for MenA was 0.88, with a two-sided 95% confidence interval lower limit of 0.64, greater than the prespecified non-inferiority margin of 0.5, thus meeting the primary study objective. Both vaccines were well tolerated. No serious adverse events were considered related to vaccination. CONCLUSIONS: The levels of MenA free saccharide and polysaccharide O-acetylation did not affect the immunogenicity of the fully liquid presentation, which was demonstrated to be non-inferior to the immunogenicity of the currently licensed MenACWY-CRM vaccine against MenA. The immunogenicity, reactogenicity and safety profiles of the two vaccine presentations were similar.


Asunto(s)
Infecciones Meningocócicas , Vacunas Meningococicas , Adulto , Anticuerpos Antibacterianos , Humanos , Vacunación , Vacunas Conjugadas
6.
J Travel Med ; 23(3)2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26994987

RESUMEN

BACKGROUND: Conventional rabies pre-exposure prophylaxis (PrEP) and Japanese encephalitis (JE) primary series vaccination regimens each require up to 4 weeks to complete and, thus, may not be feasible for individuals who need these immunizations on short notice. This Phase 3b, randomized, controlled, observer-blind study evaluated the immunogenicity and safety of concomitant administration of a purified chick embryo cell culture rabies vaccine and an inactivated, adsorbed JE vaccine according to an accelerated (1 week) regimen when compared with the conventional regimens (4 weeks). This report describes the kinetics of immune responses up to 1 year after vaccination. METHODS: A total of 661 healthy adults (18 to ≤65 years) were randomized into the following accelerated or conventional vaccine regimens: Rabies + JE-Conventional, Rabies + JE-Accelerated, Rabies-Conventional and JE-Conventional. Immunogenicity was assessed by virus neutralization tests. Safety and tolerability were also evaluated. RESULTS: Irrespective of rabies vaccination regimen, ≥97% of subjects had adequate levels of rabies virus neutralizing antibody (RVNA) concentrations (≥0.5 IU/ml) up to Day 57, with percentages of subjects with RVNA concentrations ≥0.5 IU/ml at Day 366 ranging between 68% in the Rabies + JE-Accelerated group and 80% of subjects in the Rabies-Conventional group. The Rabies + JE-Accelerated group revealed high JE neutralizing antibody titers at all-time points. At Day 366, the percentage of subjects with antibody titers indicative of seroprotection (PRNT50 titers ≥1:10) remained high across JE vaccine groups (86-94%). CONCLUSIONS: The accelerated PrEP rabies and JE vaccination regimens, once licensed, could represent a valid alternative in the short-term to currently recommended conventional regimens. The concomitant administration of these two vaccines does not compromise immune responses to any of the vaccine antigens particularly when aiming for short-term protection. Further evidence will clarify the need for and timing to administration of rabies vaccine booster doses in subjects primed with an accelerated PrEP regimen. (NCT01662440).


Asunto(s)
Encefalitis Japonesa/prevención & control , Vacunas contra la Encefalitis Japonesa/administración & dosificación , Profilaxis Pre-Exposición/métodos , Vacunas Antirrábicas/administración & dosificación , Rabia/prevención & control , Viaje , Adulto , Animales , Anticuerpos Antivirales/sangre , Austria , Embrión de Pollo , Chlorocebus aethiops , Método Doble Ciego , Femenino , Alemania , Humanos , Inmunización Secundaria , Vacunas contra la Encefalitis Japonesa/efectos adversos , Masculino , Persona de Mediana Edad , Vacunas Antirrábicas/efectos adversos , Suiza , Células Vero/virología , Adulto Joven
7.
Vaccine ; 33(15): 1824-9, 2015 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-25728316

RESUMEN

BACKGROUND: A first tick-borne encephalitis (TBE) vaccine booster in children is currently suggested 3 years after completing either a conventional (doses on Days 0, 28 and 300) or accelerated conventional (doses on Days 0, 14 and 300) TBE immunization schedule. This recommendation, however, may not be appropriate in cases where different TBE vaccines have been used interchangeably during the primary immunization series. METHODS: To provide robust data to better inform such recommendations, TBE antibody persistence was evaluated after 3-5 years in four groups of children (aged 5-15 years): two groups previously primed with three doses of Encepur(®) Children (conventional/accelerated conventional schedule); and two groups previously primed with two doses of FSME-IMMUN(®) followed by a third dose of Encepur(®) Children (conventional/accelerated conventional schedule). Immunogenicity was evaluated using neutralization (NT) assays based on both vaccine antigens as well as on the Enzyme Linked Immunosorbent Assay (ELISA). RESULTS: In the two Encepur(®) Children groups (full series), protective NT titers of ≥10 were detected in 98-100% of children up to 5 years after their last primary vaccination, irrespective of schedule. In contrast, only 65-70% subjects in the FSME-IMMUN(®) Junior groups (mixed series) displayed NT titers ≥10 after 3 years. Thus, due to lower probability of achieving/maintaining long-term protective antibody levels (recently defined by the World Health Organization as an NT titer ≥10) after this time point, both FSME-IMMUN Junior groups were discontinued. CONCLUSION: A strong antibody response persists for at least 5 years after full primary vaccination with Encepur(®) Children. The study thus provides support for extending the time interval for a first booster dose after primary vaccination (conventional/accelerated conventional schedule) with Encepur(®) Children from 3 to 5 years.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Virus de la Encefalitis Transmitidos por Garrapatas/inmunología , Encefalitis Transmitida por Garrapatas/prevención & control , Vacunas Virales/inmunología , Adolescente , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Estudios de Seguimiento , Humanos , Esquemas de Inmunización , Inmunización Secundaria , Masculino , Pruebas de Neutralización , Vacunación , Vacunas Virales/administración & dosificación , Organización Mundial de la Salud
9.
Hum Vaccin Immunother ; 10(1): 92-9, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24047817

RESUMEN

An investigational tetravalent vaccine combining pre-pandemic, MF59®-adjuvanted A/H5N1 vaccine with non-adjuvanted, trivalent, seasonal influenza vaccine has been developed, which has the potential to be used for pre-pandemic priming and to improve levels of compliance and coverage. It is important to determine whether the safety and immunogenicity of the combination vaccine is equivalent to that of the two separate vaccines when administered concomitantly. Healthy adults (n=601) were randomly assigned to three vaccination groups to receive either: (1) tetravalent vaccine and placebo concomitantly (in separate arms) on Day 1, followed by A/H5N1 vaccine on Day 22; (2) A/H5N1 vaccine and placebo concomitantly on Day 1, followed by tetravalent vaccine on Day 22; or (3) A/H5N1 and seasonal vaccines concomitantly on Day 1, followed by A/H5N1 vaccine on Day 22. Antibody responses were measured using single radial hemolysis (SRH), haemagglutination inhibition (HI), and microneutralization (MN) assays on Days 1, 22, and 43. Solicited adverse reactions were recorded for seven days after vaccination. Spontaneous adverse events were recorded throughout the study. The tetravalent vaccine elicited antibody titers equivalent to those for separate A/H5N1 and seasonal vaccines, and sufficient to meet the European licensure criteria against A/H5N1 and all three seasonal strains. Local and systemic reactions were mainly mild to moderate. No vaccine-related serious adverse events occurred. These findings demonstrate that MF59-adjuvanted A/H5N1 and seasonal influenza vaccines had an acceptable safety profile and could be effectively administered as a tetravalent formulation, supporting the possibility of integrating pre-pandemic priming into seasonal influenza vaccination programs.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Subtipo H5N1 del Virus de la Influenza A/inmunología , Virus de la Influenza B/inmunología , Vacunas contra la Influenza/inmunología , Polisorbatos/administración & dosificación , Escualeno/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Femenino , Voluntarios Sanos , Pruebas de Inhibición de Hemaglutinación , Humanos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Polisorbatos/efectos adversos , Escualeno/efectos adversos , Adulto Joven
10.
Expert Opin Biol Ther ; 13(1): 121-35, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23189937

RESUMEN

INTRODUCTION: Aflunov is an egg-derived, subunit vaccine from Novartis Vaccines and Diagnostics containing 7.5 µg of hemagglutinin (HA) from the avian A/H5N1 virus and the oil-in-water adjuvant MF59. AREAS COVERED: Aflunov behaves as a pre-pandemic vaccine. It has a good safety profile at all ages. At all ages, it induces high and persisting antibody titers and activation of HA-specific Th0/Th1 CD4(+) T cells, the levels of which correlate with the neutralizing antibody titers after a booster dose 6 months later. Aflunov triggers strong immunological memory, which persists for at least 6 - 8 years and can be rapidly boosted with a heterovariant vaccine strain, inducing very high neutralizing antibody titers within one week. These antibodies broadly and strongly cross-react with drifted H5N1 virus strains from various clades. Finally, the MF59 changes the pattern of HA recognition by antibodies that react with the HA1 more than with the HA2 region. EXPERT OPINION: The available data show that Aflunov is a pre-pandemic vaccine suitable not only for stockpiling in case of a pandemic, but also before a pandemic is declared, with the ultimate objective of preventing the onset of an influenza pandemic.


Asunto(s)
Vacunas contra la Influenza/uso terapéutico , Gripe Humana/prevención & control , Adulto , Anciano , Niño , Ensayos Clínicos como Asunto , Estudios de Factibilidad , Humanos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología
11.
PLoS One ; 8(8): e70620, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23976947

RESUMEN

Understanding the impact that human memory B-cells (MBC), primed by previous infections or vaccination, exert on neutralizing antibody responses against drifted influenza hemagglutinin (HA) is key to design best protective vaccines. A major obstacle to these studies is the lack of practical tools to analyze HA-specific MBCs in human PBMCs ex vivo. We report here an efficient method to identify MBCs carrying HA-specific BCR in frozen PBMC samples. By using fluorochrome-tagged recombinant HA baits, and vaccine antigens from mismatched influenza strains to block BCR-independent binding, we developed a protocol suitable for quantitative, functional and molecular analysis of single MBCs specific for HA from up to two different influenza strains in the same tube. This approach will permit to identify the naive and MBC precursors of plasmablasts and novel MBCs appearing in the blood following infection or vaccination, thus clarifying the actual contribution of pre-existing MBCs in antibody responses against novel influenza viruses. Finally, this protocol can allow applying high throughput deep sequencing to analyze changes in the repertoire of HA⁺ B-cells in longitudinal samples from large cohorts of vaccinees and infected subjects with the ultimate goal of understanding the in vivo B-cell dynamics driving the evolution of broadly cross-protective antibody responses.


Asunto(s)
Linfocitos B/citología , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Memoria Inmunológica , Subtipo H1N1 del Virus de la Influenza A/química , Subtipo H3N2 del Virus de la Influenza A/química , Virus de la Influenza B/química , Gripe Humana/inmunología , Anticuerpos Neutralizantes/biosíntesis , Anticuerpos Neutralizantes/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Separación Celular/métodos , Reacciones Cruzadas , Citometría de Flujo/métodos , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Virus de la Influenza B/inmunología , Vacunas contra la Influenza/química , Vacunas contra la Influenza/inmunología , Gripe Humana/virología , Unión Proteica , Anticuerpos de Dominio Único/biosíntesis , Anticuerpos de Dominio Único/inmunología
12.
Clin Vaccine Immunol ; 19(12): 1943-8, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23081815

RESUMEN

Preparedness against an A/H5N1 influenza pandemic requires well-tolerated, effective vaccines which provide both vaccine strain-specific and heterologous, cross-clade protection. This study was conducted to assess the immunogenicity and safety profile of an MF59-adjuvanted, prepandemic influenza vaccine containing A/turkey/Turkey/01/2005 (H5N1) strain viral antigen. A total of 343 participants, 194 adults (18 to 60 years) and 149 elderly individuals (≥61 years), received two doses of the investigational vaccine given 3 weeks apart. Homologous and heterologous antibody responses were analyzed by hemagglutination inhibition (HI), single radial hemolysis (SRH), and microneutralization (MN) assays 3 weeks after administration of the first vaccine dose and 3 weeks and 6 months after the second dose. Immunogenicity was assessed according to European licensure criteria for pandemic influenza vaccines. After two vaccine doses, all three European licensure criteria were met for adult and elderly subjects against the homologous vaccine strain, A/turkey/Turkey/1/2005, when analyzed by HI and SRH assays. Cross-reactive antibody responses were observed by HI and SRH analyses against the heterologous H5N1 strains, A/Indonesia/5/2005 and A/Vietnam/1194/2004, in adult and elderly subjects. Solicited local and systemic reactions were mostly mild to moderate in severity and occurred less frequently in the elderly than in adult vaccinees. In both adult and elderly subjects, MF59-adjuvanted vaccine containing 7.5 µg of A/Turkey strain influenza virus antigen was highly immunogenic, well tolerated, and able to elicit cross-clade, heterologous antibody responses against A/Indonesia and A/Vietnam strains 6 weeks after the first vaccination.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Anticuerpos Antivirales/sangre , Reacciones Cruzadas , Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Polisorbatos/administración & dosificación , Escualeno/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Adolescente , Adulto , Anciano , Anticuerpos Antivirales/inmunología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Polisorbatos/efectos adversos , Escualeno/efectos adversos , Adulto Joven
13.
Vaccine ; 30(35): 5285-92, 2012 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-22659448

RESUMEN

Vaccination is the most effective preventive strategy to control influenza. The demonstration of lot-to-lot consistency to confirm the reliability of the manufacturing process has become a mandatory step in vaccine development. This phase III, observer-blind, controlled trial assessed lot-to-lot consistency, immunogenicity, and safety of a subunit trivalent influenza vaccine (Agrippal®, Novartis Vaccines and Diagnostics) in healthy adults aged 18-49 years. The immunogenicity and safety profile of Agrippal was compared with a control vaccine (Fluvirin®, Novartis Vaccines and Diagnostics). A total of 1507 subjects were randomized 2:2:2:1 to receive one vaccination of one of the three lots of influenza vaccine or control vaccine. Antibody levels were measured by hemagglutination inhibition assay on days 1 and 22. Adverse reactions were solicited via diary cards for 7 days after vaccination, and unsolicited adverse events were collected throughout the study period. Equivalence of day 22 immune responses to the three lots was shown for each of the three strains. Robust immunogenic responses after one dose were observed for all vaccine groups, and both Center for Biologics Evaluation and Research criteria for licensure of influenza vaccines were met for all three virus strains. Both vaccines exhibited a robust safety profile and were well tolerated, with no differences in local and systemic solicited reactions or in unsolicited adverse events. The demonstration of consistency between manufacturing lots confirms for purposes of clinical development the reliability of the production process. The robust immunogenic responses and favorable safety profiles further support the use of trivalent subunit influenza vaccines Agrippal and Fluvirin for active immunization against influenza.


Asunto(s)
Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Adolescente , Adulto , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/normas , Gripe Humana/inmunología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Método Simple Ciego , Vacunación , Adulto Joven
14.
Viral Immunol ; 25(3): 216-25, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22691101

RESUMEN

The objective of this study was to evaluate and compare the immunogenicity, safety, and tolerability of two influenza subunit vaccines, a primarily European-marketed trivalent vaccine (Agrippal®, Novartis Vaccines), and a predominantly U.S.-marketed control trivalent vaccine (Fluvirin®, Novartis Vaccines), in subjects aged 3-64 y. The immunogenicity of both vaccines was evaluated according to the Center for Biologics Evaluation and Research (CBER) criteria. This clinical trial was performed between April and December 2007 in Argentina. A total of 1893 subjects were stratified into three age groups (3-8 y, 9-17 y, and 18-64 y), and randomized in a 2:1 ratio to receive either Agrippal or Fluvirin. Adolescents and adults received one dose of vaccine intramuscularly, whereas children aged 3-8 years received two vaccine doses, administered 4 wk apart. Antibody levels were measured by means of hemagglutination inhibition assay before vaccination (baseline); 21 d after the first vaccination (adults and adolescents); and, for children aged 3-8 y, 28 d after the first vaccination and 21 d after the second vaccine dose. Adverse reactions were solicited via diary cards for 7 d after each vaccination, and unsolicited adverse events were reported throughout the study period. Both vaccines were safe and well-tolerated, and elicited robust immunogenic responses in all age groups, meeting both CBER licensure criteria for all three viral strains after completion of the age-recommended vaccination schedule. These findings support the use of the trivalent subunit influenza vaccines Agrippal and Fluvirin for universal vaccination campaigns on an annual basis. ClinicalTrials.gov: NCT00464672.


Asunto(s)
Anticuerpos Antivirales/sangre , Vacunas contra la Influenza , Gripe Humana/inmunología , Gripe Humana/prevención & control , Vacunas de Productos Inactivados , Vacunas de Subunidad , Adolescente , Adulto , Argentina , Niño , Preescolar , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Vacunación , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/efectos adversos , Vacunas de Productos Inactivados/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/inmunología , Adulto Joven
15.
Clin Ther ; 32(13): 2186-97, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21316535

RESUMEN

BACKGROUND: Preparedness for an H5N1 influenza pre-pandemic requires effective and well-tolerated emergency vaccination strategies that provide both pandemic strain-specific and heterologous protection. OBJECTIVES: This was a pivotal study for the regulatory approval process for a candidate MF59-adjuvanted H5N1 vaccine. Its goals were to identify the preferred primary 2-dose vaccination schedule in adults and to assess whether the vaccine met European Committee for Medicinal Products for Human Use (CHMP) licensure criteria. METHODS: Healthy volunteers aged 18 to 60 years received 1 of 4 randomized schedules in which the 2 doses of vaccine were separated by a 1-, 2-, 3-, or 6-week interval. Three blood samples (~20 mL(-1)) were obtained from each subject: the first sample, immediately before administration of the first dose of vaccine; the second, immediately before administration of the second dose; and the third, 21 days after administration of the second dose. Hemagglutination inhibition (HI), microneutralization (MN), and single radial hemolysis (SRH) were assayed after each dose. Immunogenicity was assessed based on the CHMP licensure criteria for annual influenza vaccines (number of seroconversions or significant increase in HI titer >40%; mean geometric increase >2.5; and proportion of subjects achieving an HI titer ≥40 or SRH titer >25 mm(2) should be >70% [seroprotection]). Subjects recorded all adverse events occurring within 7 days of vaccine administration; information on any serious adverse events was collected throughout the study (duration, 202 days). RESULTS: All study participants (N = 240) were white, with a mean age of 33 years and a mean body mass index of 24.6 kg/m(2). Equal numbers of men and women were assigned to each vaccination schedule. The CHMP criterion for seroprotection was achieved when the 2 doses of vaccine were separated by 2 (76%), 3 (72%), and 6 (79%) weeks; similar results were obtained on MN and SRH analysis. On the SRH analysis, the candidate vaccine showed a heterologous immune response to the H5N1/turkey/Turkey/1/05 (NIBRG-23; clade 2) influenza antigen. The vaccine met 2 of the 3 European licensure criteria, with seroconversion rates of 69% and 65% in the groups assigned to a 2- and 3-week interval between doses, respectively, and geometric mean ratios of 4.3 and 4.5. There were no serious adverse events related to vaccination. The most common adverse events reported within 7 days of the first and second doses of vaccine were mild to moderate injection-site pain (63%-73% and 34%-48%, respectively) and fatigue (25%-30% and 13%-24%). CONCLUSIONS: Two 7.5-µg doses of MF59-adjuvanted H5N1 influenza vaccine given 2, 3, or 6 weeks apart afforded H5N1-specific immunity and met the CHMP licensure criterion for seroprotection in these healthy volunteers. Clinically relevant levels of heterologous immunity were observed when the 2 doses of vaccine were administered either 2 or 3 weeks apart; however, the licensure criterion for seroprotection was not met in this case.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza , Gripe Humana/prevención & control , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Esquema de Medicación , Femenino , Hemaglutinación/efectos de los fármacos , Pruebas de Inhibición de Hemaglutinación , Hemólisis/efectos de los fármacos , Humanos , Inmunización Secundaria , Memoria Inmunológica/efectos de los fármacos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Gripe Humana/virología , Masculino , Persona de Mediana Edad , Polisorbatos/administración & dosificación , Polisorbatos/efectos adversos , Escualeno/administración & dosificación , Escualeno/efectos adversos , Escualeno/inmunología , Adulto Joven
16.
Clin Vaccine Immunol ; 17(11): 1817-9, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20810680
17.
Influenza Other Respir Viruses ; 2(6): 243-9, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19453401

RESUMEN

Influenza is a major cause of worldwide morbidity and mortality through frequent seasonal epidemics and infrequent pandemics. Morbidity and mortality rates from seasonal influenza are highest in the most frail, such as the elderly, those with underlying chronic conditions and very young children. Antigenic mismatch between strains recommended for vaccine formulation and circulating viruses can further reduce vaccine efficacy in these populations. Seasonal influenza vaccines with enhanced, cross-reactive immunogenicity are needed to address these problems and can confer a better immune protection, particularly in seasons were antigenic mismatch occurs. A related issue for vaccine development is the growing threat of pandemic influenza caused by H5N1 avian strains. Vaccines against strains with pandemic potential offer the best approach for reducing the potential impact of a pandemic. However, current non-adjuvanted pre-pandemic vaccines offer suboptimal immunogenicity against H5N1. For both seasonal and pre-pandemic vaccines, the addition of adjuvants may be the best approach for providing enhanced cross-reactive immunogenicity. MF59, the first oil-in-water emulsion licensed as an adjuvant for human use, can enhance vaccine immune responses through multiple mechanisms. A trivalent MF59-adjuvanted seasonal influenza vaccine (Fluad has shown to induce significantly higher immune responses to influenza vaccination in the elderly, compared with non-adjuvanted vaccines, and to provide cross-reactive immunity against divergent influenza strains. Similar results have been generated with a MF59-adjuvanted H5N1 pre-pandemic vaccine, which showed higher and broader immunogenicity compared with non-adjuvanted pre-pandemic vaccines.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/farmacología , Brotes de Enfermedades/prevención & control , Gripe Humana/prevención & control , Polisorbatos/administración & dosificación , Polisorbatos/farmacología , Escualeno/administración & dosificación , Escualeno/farmacología , Vacunas/inmunología , Animales , Anticuerpos Antivirales/sangre , Reacciones Cruzadas , Humanos , Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza
18.
Clin Vaccine Immunol ; 13(9): 1010-3, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16960112

RESUMEN

Squalene is a naturally occurring oil which has been used in the development of vaccine adjuvants, such as the oil-in-water emulsion MF59. In past years, by use of noncontrolled and nonvalidated assays, a claim was made that antisqualene antibodies were detectable in the sera of individuals with the so-called Gulf War syndrome. Using a validated enzyme-linked immunosorbent assay for the quantitation of immunoglobulin G (IgG) and IgM antibodies against squalene, we demonstrated that antisqualene antibodies are frequently detectable at very low titers in the sera of subjects who were never immunized with vaccines containing squalene. More importantly, vaccination with a subunit influenza vaccine with the MF59 adjuvant neither induced antisqualene antibodies nor enhanced preexisting antisqualene antibody titers. In conclusion, antisqualene antibodies are not increased by immunization with vaccines with the MF59 adjuvant. These data extend the safety profile of the MF59 emulsion adjuvant.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Formación de Anticuerpos , Escualeno/metabolismo , Vacunas/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Adulto , Anciano , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/inmunología , Persona de Mediana Edad , Vacunas/administración & dosificación
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