2,436 research outputs found
Kinetics and persistence of anti-SARS-CoV-2 neutralisation and antibodies after BNT162b2 vaccination in a Swiss cohort
Introduction: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), substantial effort has been made to gain knowledge about the immunity elicited by infection or vaccination.
Methods: We studied the kinetics of antibodies and virus neutralisation induced by vaccination with BNT162b2 in a Swiss cohort of SARS-CoV-2 naïve (n = 40) and convalescent (n = 9) persons. Blood sera were analysed in a live virus neutralisation assay and specific IgG and IgA levels were measured by enzyme-linked immunoassay and analysed by descriptive statistics.
Results: Virus neutralisation was detected in all individuals 2-4 weeks after the second vaccine. Both neutralisation and antibodies remained positive for >4 months. Neutralisation and antibodies showed positive correlation, but immunoglobulin G (IgG) and immunoglobulin A (IgA) seroconversion took place 2-4 weeks faster than neutralisation. Spike-protein specific IgG levels rose significantly faster and were more stable over time than virus neutralisation titres or IgA responses. For naïve but not convalescent persons, a clear boosting effect was observed. Convalescent individuals showed faster, more robust and longer-lasting immune responses after vaccination compared to noninfected persons. No threshold could be determined for spike protein-specific IgG or IgA that would confer protection in the neutralisation assay, implicating the need for a better correlate of protection then antibody titres alone.
Conclusions: This study clearly shows the complex translation of antibody data and virus neutralisation, while supporting the evidence of a single dose being sufficient for effective antibody response in convalescent individuals.
Trial registration: ClinicalTrials.gov NCT04979871.
Keywords: BNT162b2; COVID-19; SARS-CoV-2; antibody response; mRNA vaccine; neutralisation assay
Power resources and successful trade union actions that address precarity in adverse contexts: The case of Central and Eastern Europe
Is it possible for trade unions to fight precarity in an adverse global context? Although existing research suggests this is possible, there is limited understanding of the interplay of resources that enable unions to address precarity in deregulated markets. This study employs a power resource approach to investigate how unions overcome their external constraints. It draws upon 130 in-depth interviews with key informants across nine Central and Eastern European countries to investigate successful and unsuccessful union actions in sectors with differing external resources. In each sector, unions that mobilise their internal resources have been able to reduce various precarity dimensions, such as low wages, lack of voice, and irregular working time. The results reveal that unions whose objectives are based on convincing win–win discourses can make strides, acting as drivers of change in precarity patterns even in unfavourable conditions. Moreover, the study introduces a multi-dimensional conceptualisation of union success, identifying union actions that result in measurable improvements in precarity dimensions for all worker types. To deepen understanding of the role unions play in fighting precarity in adverse contexts, future research could investigate union actions that improve a wider range of precarity dimensions for all workers
Targeting Ara h 2 with human‐derived monoclonal antibodies prevents peanut‐induced anaphylaxis in mice
Background: Peanut allergy is a type‐I hypersensitivity immune reaction mediated by the binding of peanut allergens to IgE‐FcεRI complexes on mast cells and basophils and by their subsequent cellular degranulation. Of all major peanut allergens, Ara h 2 is considered the most anaphylactic. With few options but allergen avoidance, effective treatment of allergic patients is needed. Passive immunotherapy (herein called PIT) based on prophylactic administration of peanut‐specific monoclonal antibodies (mAbs) may present a promising treatment option for this under‐served disease.
Method: Fully human recombinant anti‐peanut IgG mAbs were tested in mice sensitized to peanut allergen extract. Allergic mice received intravenous immunotherapy with anti‐peanut Ara h 2‐specific IgG1 or IgG4 mAbs cocktails, and were then challenged by a systemic injection of high‐dose peanut allergen extract. The protection from allergic anaphylaxis was measured by monitoring the core body temperature.
Results: PIT with peanut‐specific mAbs was associated with a significant and dose‐dependent reduction of anaphylactic reactions in peanut‐sensitized mice challenged with peanut allergen extract. Complete protection was observed at doses approximately 0.3–0.6 mg mAbs. Mixtures of mAbs were more effective than single mAbs, and effective treatment could be obtained with mAbs of both IgG1 and IgG4 subclasses. The therapeutic effect of anti‐Ara h 2 mAbs was based on allergen neutralization and independent of the Fcγ receptor and mast‐cell inhibition.
Conclusion: This is the first report that shows that human‐derived anti‐peanut mAbs can prevent allergic anaphylaxis in mice. The study demonstrates that neutralizing allergenic epitopes on Ara h 2 by mAbs may represent a promising treatment option in peanut‐allergy
Determination of the number of light neutrino species from single photon production at LEP
A determination of the number of light neutrino families performed by measuring the cross section of single photon production in \ee\ collision near the \Zo\ resonance is reported. From an integrated luminosity of , collected during the years 1991--94, we have observed 2091 single photon candidates with an energy above 1~\GeV\ in the polar angular region . From a maximum likelihood fit to the single photon cross section, the \Zo\ decay width into invisible particles is measured to be \Ginv = 498 \pm 12 \mathrm{(stat)} \pm 12 \mathrm{(sys)~MeV}. Using the Standard Model couplings of neutrinos to the \Zo, the number of light neutrino species is determined to be $N_\nu = 2.98 \pm 0.07 (\mathrm{stat}) \pm 0.07 (\mathrm{sys}).
Search for R-Parity Breaking Sneutrino Exchange at LEP
We report on a search for R--parity breaking effects due to supersymmetric tau--sneutrino exchange in the reactions e+e- to e+e- and e+e- to mu+mu- at centre--of--mass energies from 91~{\GeV} to 172~{\GeV}, using the L3 detector at LEP. No evidence for deviations from the Standard Model expectations of the measured cross sections and forward--backward asymmetries for these reactions is found. Upper limits for the couplings and for sneutrino masses up to m_{\SNT} \leq 190~\GeV are determined from an analysis of the expected effects due to tau sneutrino exchange
Search for charged Higgs bosons in collisions at centre-of-mass energies between 130 and 183 GeV
A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at centre-of-mass energies from \mbox{130 to 183 \GeV{}}, corresponding to an integrated luminosity of 88.3 \pb. The Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed candidates are consistent with the expectations from Standard Model background processes. A lower limit of 57.5 \GeV{} on the charged Higgs mass is derived at 95\% CL, independent of the decay branching ratio \mathrm{Br(H^\pm\ra \tau\nu)}
Heavy Quarkonium Production in Z Decays
We report measurements of the inclusive production of heavy quarkonium states in decays based on the analysis of 3.6 million hadronic events collected by the L3 detector at LEP. The measurement of inclusive J production and an improved confidence level upper limit on production are presented. In addition, two independent measurements of the ratio, , of prompt J mesons to those from B decay are made using two different isolation cuts to separate prompt J mesons from J mesons produced in the decays of b hadrons. The results are: % \begin{eqnarray} \mathrm{Br}(\mathrm{Z} \rightarrow \mathrm{J} + \mathrm{X}) & = & (3.21 \pm 0.21 \; \mathrm{(stat.)} \; ^{+ 0.19}_{- 0.28} \; \mathrm{(sys.)} ) \times 10^{-3} \; , \nonumber \\ \mathrm{Br}(\mathrm {Z} \rightarrow \Upsilon(\mathrm{1S} + X) & < & 4.4 \times 10^{-5} \; , \nonumber \\ %% f_{\mathrm{p}} & = & (7.1 \pm 2.1 \; \mathrm{(stat.)} \; \pm 1.2 \; \mathrm{(sys.)} \; ^{+1.5}_{-0.8} \;\mathrm{(theo.)} ) \times 10^{-2} \; . \nonumbe
Study of Neutral-Current Four-Fermion and ZZ Production in Collisions at = 183 GeV
Study of Neutral--Current Four--Fermion and ZZ \\ Production in Collisions at 183 GeV A study of neutral--current four--fermion processes is performed using a data sample corresponding to 55.3~pb of integrated luminosity collected by the L3 detector at LEP at an average centre--of--mass energy of 183~\GeV. The neutral--current four--fermion cross sections for final states with a pair of charged leptons plus jets and with four charged leptons are measured to be consistent with the Standard Model predictions. Events with fermion pair masses close to the Z boson mass are selected in all observable final states and the ZZ production cross section is measured to be %\begin{center} %\end{center} in agreement with the Standard Model expectation. No evidence for the existence of anomalous triple gauge boson ZZZ and ZZ couplings is found and limits on these couplings are set
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