213 research outputs found

    Actes unilatéraux

    Get PDF

    Vaccination with viral vectors expressing NP, M1 and chimeric hemagglutinin induces broad protection against influenza virus challenge in mice

    Get PDF
    Seasonal influenza virus infections cause up to half a million deaths each year, the majority of which are older adults. Annual influenza virus vaccination protects against disease, but in the event of a mismatch between the circulating strain and vaccine strain, vaccine effectiveness is severely impacted. Therefore, there is an urgent need for a vaccine that induces broad protection against drifted seasonal and emerging pandemic influenza viruses. One approach in designing such a universal influenza virus vaccine is based on targeting conserved regions of the influenza virus hemagglutinin (HA), the major glycoprotein on the surface of the virus. Using chimeric hemagglutinin constructs (cHA), the immune system can be primed to produce antibody responses against the conserved immunosubdominant stalk region rather than the variable immunodominant head region. Furthermore, replication deficient viral vectors based on Chimpanzee Adenovirus (ChAdOx1) and Modified Vaccinia Ankara (MVA) virus expressing the influenza virus internal antigens, such as the nucleoprotein (NP) and the matrix protein 1 (M1), are capable of inducing strong influenza specific T cell responses in vaccinated individuals. This is another approach towards a broadly cross-protective influenza vaccine given the degree of conservation of NP and M1 across different influenza virus strains. Here, we combine these two platforms to evaluate the efficacy of a viral vector-based group 2 cHA intramuscular vaccination regime in mice to confer protection against influenza virus challenge of matched and mismatched group 2 strains. We show that vectored vaccines expressing both cHA and an NP-M1 fusion protein, in a prime-boost regimen (with different cHAs given at each vaccination), provide enhanced protection against H3N2 and H10N8 virus challenge when compared to vaccination with cHA alone or NP-M1 alone. The vaccine induced antibody responses against divergent HAs, NP, M1, and whole virus correlated with nature of administered vaccine and extent of protection seen across vaccinated groups. Influenza specific T cell responses were also increased in the vectored vaccines expressing both the cHA and the NP-M1 fusion protein. For further characterization, we are interested in looking at an optimal vaccination regimen, the possibility of an additional boost to induce cross-reactive antibodies, and the nature of the induced antibodies. Overall, these results improve our understanding of vaccination platforms capable of harnessing cellular and humoral immunity with the ultimate goal of designing a universal influenza vaccine

    Satisfaction with Life Scale among adolescents and young adults in Portugal: extending evidence of construct validity

    Get PDF
    The paper presents three empirical studies designed to extend the test of the construct validity of the Satisfaction With Life Scale (SWLS) among Portuguese students. In the first study, the responses of 461 elementary and secondary education students were submitted to a principal component analysis. A solution of one single factor was chosen, accounting for 55.7 % of the total variance, with Cronbach alpha coefficient and inter-item correlation above .70 and .20, respectively. The second study used a sample of 317 undergraduate students and registered a similar factor solution for SWLS (/pq = 0.99), which accounted for 65.6 % of the total variance (Cronbach alpha .89 and inter-item correlation above .20). A test–retest analysis registered coefficients of .70 (T2) and .77 (T3) and no significant statistically differences between T2, T3 and T1. The third study used a sample of 107 foster care youths from elementary and secondary education. Confirmatory factor analysis results indicate adequate fit indexes for the one-factor solution (v2/df = 2.70, GFI = .96, CFI = .96), which showed convergent validity, reliability and homogeneity. In conclusion, there is psychometric evidence for the one-factor structure of the SWLS in Portugal.FCTCOMPET

    Dimensionality and measurement invariance in the Satisfaction with Life Scale in Norway

    Get PDF
    Purpose Results from previous studies examining the dimensionality and factorial invariance of the Satisfaction with Life Scale (SWLS) are inconsistent and often based on small samples. This study examines the factorial structure and factorial invariance of the SWLS in a Norwegian sample. Methods Confirmatory factor analysis (AMOS) was conducted to explore dimensionality and test for measurement invariance in factor structure, factor loadings, intercepts, and residual variance across gender and four age groups in a large (N = 4,984), nationally representative sample of Norwegian men and women (15–79 years). Results The data supported a modified unidimensional structure. Factor loadings could be constrained to equality between the sexes, indicating metric invariance between genders. Further testing indicated invariance also at the strong and strict levels, thus allowing analyses involving group means. The SWLS was shown to be sensitive to age, however, at the strong and strict levels of invariance testing. Conclusion In conclusion, the results in this Norwegian study seem to confirm that a unidimensional structure is acceptable, but that a modified single-factor model with correlations between error terms of items 4 and 5 is preferred. Additionally, comparisons may be made between the genders. Caution must be exerted when comparing age groups

    West Nile Virus–associated Flaccid Paralysis

    Get PDF
    The causes and frequency of acute paralysis and respiratory failure with West Nile virus (WNV) infection are incompletely understood. During the summer and fall of 2003, we conducted a prospective, population-based study among residents of a 3-county area in Colorado, United States, with developing WNV-associated paralysis. Thirty-two patients with developing paralysis and acute WNV infection were identified. Causes included a poliomyelitislike syndrome in 27 (84%) patients and a Guillain-Barré–like syndrome in 4 (13%); 1 had brachial plexus involvement alone. The incidence of poliomyelitislike syndrome was 3.7/100,000. Twelve patients (38%), including 1 with Guillain-Barré–like syndrome, had acute respiratory failure that required endotracheal intubation. At 4 months, 3 patients with respiratory failure died, 2 remained intubated, 25 showed various degrees of improvement, and 2 were lost to followup. A poliomyelitislike syndrome likely involving spinal anterior horn cells is the most common mechanism of WNV-associated paralysis and is associated with significant short- and long-term illness and death

    Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

    Get PDF
    This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction

    The Curse of Online Friends: The Detrimental Effects of Online Social Network Usage on Well-Being

    Get PDF
    In the pursuit of happiness, it has been conventionally accepted that more friends would bring us a better quality of life. However, with the advent of social networking sites, unprecedented social influence has pervaded our daily lives. Across two studies we show that even though people feel more satisfied with their lives when they view the friends added on Facebook, reading friends’ posts reduces their well-being. This is because the more friends people have on Facebook, the more ostentatious information they see. The resultant drop in life satisfaction occurs because people fail to draw a connection between the number of friends and the amount of ostentatious information. Moreover, this decrease in life satisfaction is mediated by envy. We contribute to the literature on consumer well-being by identifying a novel and ubiquitous phenomenon of making social comparisons with hundreds of people, a phenomenon that arose with the advent of social networking and was previously outside the scope of social comparison literature
    corecore