High accumulation in tobacco seeds of hemagglutinin antigen from avian (H5N1) influenza.

Tobacco seeds can be used as a cost effective system for production of recombinant vaccines. Avian influenza is an important respiratory pathogen that causes a high degree of mortality and becomes a serious threat for the poultry industry. A safe vaccine against avian flu produced at low cost could help to prevent future outbreaks. We have genetically engineered tobacco plants to express extracellular domain of hemagglutinin protein from H5N1 avian influenza virus as an inexpensive alternative for production purposes. Two regulatory sequences of seed storage protein genes from Phaseolus vulgaris L. were used to direct the expression, yielding 3.0 mg of the viral antigen per g of seeds. The production and stability of seed-produced recombinant HA protein was characterized by different molecular techniques. The aqueous extract of tobacco seed proteins was used for subcutaneous immunization of chickens, which developed antibodies that inhibited the agglutination of erythrocytes after the second application of the antigen. The feasibility of using tobacco seeds as a vaccine carrier is discussed.

Influenza vaccine: development of a novel intranasal and subcutaneous recombinant adjuvant.

The synthetic peptide GK-1, derived from Taenia crassiceps, enhances the protection induced by human influenza vaccine in both young and aged mice. Herein, the adjuvant properties of GK-1 fused to the pVIII protein of a heat-inactivated phagemid vector (FGK1) when co-administered with the influenza vaccine were assessed, to evaluate its feasibility as a low-cost adjuvant. In mice, FGK1 significantly increased the expected IgG and IgA anti-influenza antibody levels both in sera and in bronchoalveolar fluids when intranasally or subcutaneously co-administered with influenza vaccine. Single-dose pig co-immunization with FGK1 and influenza vaccine induced serum levels of IgG anti-influenza antibodies similar to those elicited by a two-dose immunization with the influenza vaccine alone. Preclinical evaluation of FGK1 with the influenza vaccine is currently in progress, in order to recommend its use for veterinary purposes.

Immunogenicity and reactogenicity of 2009 influenza A (H1N1) inactivated monovalent non-adjuvanted vaccine in elderly and immunocompromised patients.

BACKGROUND: Immunosuppressed individuals present serious morbidity and mortality from influenza, therefore it is important to understand the safety and immunogenicity of influenza vaccination among them. METHODS: This multicenter cohort study evaluated the immunogenicity and reactogenicity of an inactivated, monovalent, non-adjuvanted pandemic (H1N1) 2009 vaccine among the elderly, HIV-infected, rheumatoid arthritis (RA), cancer, kidney transplant, and juvenile idiopathic arthritis (JIA) patients. Participants were included during routine clinical visits, and vaccinated according to conventional influenza vaccination schedules. Antibody response was measured by the hemagglutination-inhibition assay, before and 21 days after vaccination. RESULTS: 319 patients with cancer, 260 with RA, 256 HIV-infected, 149 elderly individuals, 85 kidney transplant recipients, and 83 with JIA were included. The proportions of seroprotection, seroconversion, and the geometric mean titer ratios postvaccination were, respectively: 37.6%, 31.8%, and 3.2 among kidney transplant recipients, 61.5%, 53.1%, and 7.5 among RA patients, 63.1%, 55.7%, and 5.7 among the elderly, 59.0%, 54.7%, and 5.9 among HIV-infected patients, 52.4%, 49.2%, and 5.3 among cancer patients, 85.5%, 78.3%, and 16.5 among JIA patients. The vaccine was well tolerated, with no reported severe adverse events. CONCLUSIONS: The vaccine was safe among all groups, with an acceptable immunogenicity among the elderly and JIA patients, however new vaccination strategies should be explored to improve the immune response of immunocompromised adult patients. (ClinicalTrials.gov, NCT01218685).

Incidencia de enfermedades respiratorias en funcionarios vacunados y no vacunados contra la influenza: Servicio de Salud Metropolitano Sur Oriente año 2000 / Incidence of acute respiratory disease among health care personnel with and without influenza vaccination: Servicio de Salud Metropolitano Sur Oriente year 2000

Durante el período invernal las infecciones respiratorias agudas (IRA) son causa de un alto número de licencias médicas, cuando este hecho se manifiesta en el personal de salud, que se encuentra más expuesto y que tiene como objetivo atender a la población en este período, no sólo se trata de ausentismo laboral sino un menoscabo importante en la oferta de atención médica. Estos dos hechos han sido los pilares fundamentales, en muchos países, que justifican la vacunación del personal de salud contra la influenza. Se presenta un estudio de cohorte del personal del Servicio de Salud Metropolitano Sur Oriente vacunado y no vacunado contra la influenza y, la incidencia de infecciones respiratorias durante el año 2000. El total del personal vacunado fue de 3.479 personas y los no vacunados alcanzaron a 272; los casos de infección respiratorias, ocurridos en el período mayo-octubre del mismo año alcanzaron a 644 eventos que se clasificaron en CIE-10 con los códigos: J-00 a J-22 (infecciones agudas del sistema respiratorio). J-45 (asma) y H-67 (otitis media aguda). los resultados de este trabajo demuestran una menor incidencia de gripe, que generan licencia médica, en los funcionarios expuestos a vacuna antiinfluenza. La diferencia entre expuestos y no expuestos a la vacuna fue estadísticamente significativa (p < 0,0001; X²); la vacuna actuó como un mecanismo de protección efectivo, disminuyendo el riesgo de enfermar de influenza (RR = 0,13; IC 0,086 - 0,203). Si bien no es el objetivo de esta vacunación la protección contra otras IRA, se pudo constatar una disminución en la ocurrencia de otras patologías respiratorias entre los vacunados, que resultaron también significativas en el análisis estadísticos

Safety and antigenicity of influenza A/Hong Kong/68-ts-1 (E) (H3N2).

Influenza A/Hong Kong/68-ts-1 [E] (H3N2) vaccine was administered intranasally to 18 seronegative children 14 to 32 months of age. Fourteen children, 78%, shed influenza A/Hong Kong virus for a mean of eight days following vaccination. Sixteen children, 89%, experienced a fourfold or greater rise in hemagglutination-inhibition antibody. Some children appeared to experience a febrile reaction to the vaccine although interpretation of this data was complicated by intercurrent illness. These findings demonstrate that influenza A ts-1 [E] replicates more readily in the young seronegative child than in the HAI negative adult. In addition, the temperature-sensitive marker of the vaccine was not genetically stable in four of the vaccinated children. Careful evaluation of any future live respiratory viral vaccines needs to be undertaken in the young seronegative child before the vaccine's safety is fully established.