801 research outputs found
COVID-19 and inequalities in educational achievement in Italy
We use longitudinal data from over 1.5 million Italian students to examine differences in the mathematics and reading achievement of students who completed primary and lower secondary school in 2020–21 (COVID cohort) and those who completed it in 2018–19 (non-COVID cohort). We also examine the evolution of inequalities by gender, socio-economic condition, and prior academic achievement during the pandemic. On average, the primary school COVID cohort experienced a small increase in reading achievement and a drop in mathematics achievement compared to the non-COVID cohort. The lower secondary school COVID cohort experienced a large reduction in mathematics achievement and a smaller reduction in reading achievement compared to the non-COVID cohort. Previously middle-achieving students suffered the most from the pandemic, while high achievers gained. Socio-economic inequalities in achievement remained stable for secondary school students and somewhat decreased for primary school students between the non-COVID and COVID cohorts. Gender disparities were broadly reduced across domains and school levels, except for primary school mat
Chimeric influenza haemagglutinins: Generation and use in pseudotype neutralization assays
Recently chimeric influenza haemagglutinins (cHAs) have been generated as potential 'universal' vaccination antigens and as tools to identify HA stalk-directed antibodies via their use as antigens in ELISA, and virus or pseudotype-based neutralization assays. The original methods [1], [2] used for their generation require the amplification of regions of interest (head and stalk) using primers containing SapI sites and subsequent cloning into pDZ plasmid. This requires precise primer design, checking for the absence of SapI sites in the sequence of interest, and multi-segment ligation. As an alternative strategy we have developed and optimized a new protocol for assembling the cHA by exploiting Gibson Assembly. •This method also requires precise primer design, but it is rapid and methodologically simple to perform. We have evaluated that using this method it is possible to construct a cHA encoding DNA in less than a week.•Additional weeks are however necessary to optimize the production of pseudotyped lentiviral particles and to perform neutralization assays using them as surrogate antigens.•In comparison to the original protocols, we have also observed that performing parallel neutralization assays using pseudotypes harbouring the two parental HAs, permits effective delineation between stalk and head antibody responses in the samples tested
Recommended from our members
The production and development of H7 Influenza virus pseudotypes for the study of humoral responses against avian viruses
In recent years, high pathogenicity avian influenza (HPAI) virus, H5N1, low pathogenicity avian influenza (LPAI) virus, H9N2, and both HPAI and LPAI H7 viruses have proved devastating for the affected economies reliant on poultry industry, and have posed serious public health concerns. These viruses have repeatedly caused zoonotic disease in humans, raising concerns of a potential influenza pandemic. Despite the focus on the HPAI H5N1 outbreak in 1997 some H7 strains have also shown to be occasionally adaptable to infecting humans. Therefore, applying knowledge of the H5 virus evolution and spread to the development of sensitive
serological methods is likely to improve our ability to understand and respond to the emergence of other HPAI and LPAI viruses, present within the avian populations, with the potential to infect humans and other species. In the present study we describe the construction and production of lentiviral pseudotypes bearing envelope glycoproteins of LPAI and HPAI H7 avian influenza viruses, which have been responsible for several outbreaks in the past decade. The H7 pseudotypes were evaluated in pseudotype-based neutralization (pp-NT) assays in order to detect and quantify the presence of neutralizing antibodies in avian sera, which were confirmed H7 positive by inhibition of haemagglutination (HI) test. Overall, our results substantiate influenza virus pseudotype neutralization as a robust tool for influenza sero-surveillance
Recommended from our members
The use of equine influenza pseudotypes for serological screening
Standard assays used for influenza serology present certain practical issues, such as inter-laboratory variability,
complex protocols and the necessity for handling certain virus strains in high biological containment facilities. In an attempt to address this, avian and human influenza HA pseudotyped retroviruses have been successfully employed in antibody neutralization assays. In this study we generated an equine influenza pseudotyped lentivirus for serological screening. This was achieved by co-transfection of HEK293T cells with plasmids expressing the haemagglutinin (HA) protein of an H3N8 subtype equine influenza virus strain, HIV gag-pol and firefly luciferase reporter genes and harvesting virus from supernatant. In order to produce infective pseudotype particles it was necessary to additionally co-transfect a plasmid encoding the TMPRSS2 endoprotease to cleave the HA. High titre pseudotype virus (PV) was then used in PV antibody neutralization assays (PVNAs) to successfully distinguish between vaccinated and non-vaccinated equines. The sera were also screened by single radial haemolysis (SRH) assay. There was a 65% correlation between the results of the two assays, with the PVNA assay appearing slightly more sensitive. Future work will extend the testing of the PVNA with a larger number of
serum samples to assess sensitivity/specificity, inter/intra-laboratory variability and to define a protective titre
- …