Serological response and breakthrough infection after COVID-19 vaccination in patients with cirrhosis and post-liver transplant

BACKGROUND: Vaccine hesitancy and lack of access remain major issues in disseminating COVID-19 vaccination to liver patients globally. Factors predicting poor response to vaccination and risk of breakthrough infection are important data to target booster vaccine programs. The primary aim of the current study was to measure humoral responses to 2 doses of COVID-19 vaccine. Secondary aims included the determination of factors predicting breakthrough infection. METHODS: COVID-19 vaccination and Biomarkers in cirrhosis And post-Liver Transplantation is a prospective, multicenter, observational case-control study. Participants were recruited at 4-10 weeks following first and second vaccine doses in cirrhosis [n = 325; 94% messenger RNA (mRNA) and 6% viral vaccine], autoimmune liver disease (AILD) (n = 120; 77% mRNA and 23% viral vaccine), post-liver transplant (LT) (n = 146; 96% mRNA and 3% viral vaccine), and healthy controls (n = 51; 72% mRNA, 24% viral and 4% heterologous combination). Serological end points were measured, and data regarding breakthrough SARS-CoV-2 infection were collected. RESULTS: After adjusting by age, sex, and time of sample collection, anti-Spike IgG levels were the lowest in post-LT patients compared to cirrhosis (p < 0.0001), AILD (p < 0.0001), and control (p = 0.002). Factors predicting reduced responses included older age, Child-Turcotte-Pugh B/C, and elevated IL-6 in cirrhosis; non-mRNA vaccine in AILD; and coronary artery disease, use of mycophenolate and dysregulated B-call activating factor, and lymphotoxin-α levels in LT. Incident infection occurred in 6.6%, 10.6%, 7.4%, and 15.6% of cirrhosis, AILD, post-LT, and control, respectively. The only independent factor predicting infection in cirrhosis was low albumin level. CONCLUSIONS: LT patients present the lowest response to the SARS-CoV-2 vaccine. In cirrhosis, the reduced response is associated with older age, stage of liver disease and systemic inflammation, and breakthrough infection with low albumin level

First measurement of the |t|-dependence of coherent J/ψ photonuclear production

The first measurement of the cross section for coherent J/ψ photoproduction as a function of |t|, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the ALICE detector in ultra-peripheral Pb–Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02TeV with the J/ψ produced in the central rapidity region |y|<0.8, which corresponds to the small Bjorken-x range (0.3−1.4)×10−3. The measured |t|-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according to the leading-twist approximation, or gluon-saturation effects from the impact-parameter dependent Balitsky–Kovchegov equation. These new results are therefore a valid tool to constrain the relevant model parameters and to investigate the transverse gluonic structure at very low Bjorken-x.publishedVersio

Spin alignment measurements using vector mesons with ALICE detector at the LHC

We present new measurements related to spin alignment of K*(0) vector mesons at mid-rapidity for Pb-Pb collisions at root s(NN) = 2.76 and 5.02 TeV. The spin alignment measurements are carried out with respect to production plane and 2nd order event plane. At low p(T) the spin density matrix element rho(00) for K*(0) is found to have values slightly below 1/3, while it is consistent with 1/3, i.e. no spin alignment, at high p(T). Similar values of rho(00) are observed with respect to both production plane and event plane. Within statistical and systematic uncertainties, rho(00) values are also found to be independent of root s(NN). rho(00) also shows centrality dependence with maximum deviation from 1/3 for mid-central collisions with respect to both the kinematic planes. The measurements for K*(0) in pp collisions at root s = 13 TeV and for K-s(0) (a spin 0 hadron) in 20-40\% central Pb-Pb collisions at root s(NN) = 2.76 TeV are consistent with no spin alignment

Muon physics at forward rapidity with the ALICE detector upgrade

ALICE is the experiment specifically designed to study the Quark-Gluon Plasma (QGP) in heavy-ion collisions at the CERN LHC. The ALICE detector will be upgraded during the Long Shutdown 2, planned for 2019-2020, in order to cope with the maximum interaction rate of 50 kHz of Pb-Pb collisions foreseen for Runs 3 and 4. The ambitious programme of high-precision measurements, expected for muon physics after 2020, requires an upgrade of the front-end and readout electronics of the existing Muon Spectrometer. This concerns the Cathode Pad Chambers (CPC) used for tracking and the Resistive Plate Chambers (RPC) used for triggering and for muon identification. The Muon Forward Tracker (MFT), an internal tracker added in front of the front absorber of the existing Muon Spectrometer, is also part of the ALICE detector upgrade programme. It is based on an assembly of circular planes made of Monolithic Active Pixel Sensors (MAPS), covering the pseudorapidity range 2.5 < eta < 3.6. The MFT will improve present measurements and enable new ones. A selection of results from physics performance studies will be presented, together with an overview of the technical aspects of the upgrade project

Open heavy-flavour production and elliptic flow in p-Pb collisions at the LHC with ALICE

Measurements of open heavy flavour production in p-A collisions allow the investigation of Cold Nuclear Matter effects. In addition, they are an important tool for a complementary investigation of the long-range correlations found in small systems in the light flavour sector. In this work, production measurements of D mesons at mid-rapidity in p-Pb collisions at root S-NN = 5.02 TeV are reported. Production yields are also reported for the heavy-flavour hadron decay electrons at central rapidity at root(SNN) = 5.02 and 8.16 TeV. The elliptic flow (nu(2)) of heavy-flavour hadron decay electrons in high multiplicity p-Pb collisions at root(SNN) = 5.02 TeV is found to be positive with a significance larger than 5 sigma

Unveiling the strong interaction among hadrons at the LHC

ALICE Collaboration., Acharya, S., Adamová, D. et al. Publisher Correction: Unveiling the strong interaction among hadrons at the LHC. Nature 590, E13 (2021). https://doi.org/10.1038/s41586-020-03142-2The study of (anti-)deuteron production in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper the production of (anti-)deuterons is studied as a function of the charged particle multiplicity in inelastic pp collisions at root s = 13 TeV using the ALICE experiment. Thanks to the large number of accumulated minimum bias events, it has been possible to measure (anti-)deuteron production in pp collisions up to the same charged particle multiplicity (dN(ch)/d eta similar to 26) as measured in p-Pb collisions at similar centre-of-mass energies. Within the uncertainties, the deuteron yield in pp collisions resembles the one in p-Pb interactions, suggesting a common formation mechanism behind the production of light nuclei in hadronic interactions. In this context the measurements are compared with the expectations of coalescence and statistical hadronisation models (SHM).Peer reviewe

Light (anti-)nuclei production and elliptic flow at the LHC with ALICE

Results on the production of stable light nuclei, including deuterons, He-3, He-4 and the corresponding anti-nuclei, in Pb-Pb collisions at root s(NN) = 2.76 TeV and root s(NN) = 5.02 TeV are presented and compared with theoretical predictions and with the results in small systems to provide insight into the production mechanisms of (anti-)nuclei at colliders. The experimental results are presented giving a critical view of their comparison to the expectations from coalescence and hydrodynamic models that aim at describing both the p(T)-spectra and the elliptic flow

Higher moment fluctuations of identified particle distributions from ALICE

Cumulants of conserved charges fluctuations are regarded as a potential tool to study the criticality in the QCD phase diagram and to determine the freeze-out parameters in a model-independent way. At LHC energies, the measurements of the ratio of the net-baryon (net-proton) cumulants can be used to test the lattice QCD predictions. In this work, we present the first measurements of cumulants of the net-proton number distributions up to $4^{th}$ order in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 and 5.02 TeV as a function of collision centrality. We compare our cumulant ratios results with the STAR experiment net-proton results measured in the first phase of the Beam Energy Scan program at RHIC. The results can be used to obtain the chemical freeze-out parameters at LHC.Comment: 4 pages, 3 figures, Proceedings of XXVIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018

Direct photon elliptic flow in Pb-Pb collisions at root s(NN)=2.76 TeV

The elliptic flow of inclusive and direct photons was measured at mid-rapidity in two centrality classes 0-20% and 20-40% in Pb-Pb collisions at root s(NN) = 2.76 TeV by ALICE. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the detector material with the e(broken vertical bar)e pairs reconstructed in the central tracking system. The results of the two methods were combined and the direct-photon elliptic flow was extracted in the transverse momentum range 0.9 < p(T) < 6.2 GeV/c. A comparison to RHIC data shows a similar magnitude of the measured direct-photon elliptic flow. Hydrodynamic and transport model calculations are systematically lower than the data, but are found to be compatible. (C) 2018 The Author. Published by Elsevier B.V.Peer reviewe

Measuring (KSK +/-)-K-0 interactions using pp collisions at root s=7 TeV

We present the first measurements of femtoscopic correlations between the K-S(0) and K-+/- particles in pp collisions at root s = 7 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding solely via the a(0)(980) resonance. The extracted kaon source radius and correlation strength parameters for (KSK-)-K-0 are found to be equal within the experimental uncertainties to those for (KSK+)-K-0. Results of the present study are compared with those from identical-kaon femtoscopic studies also performed with pp collisions at root s = 7 TeV by ALICE and with a (KSK +/-)-K-0 measurement in Pb-Pb collisions at root s(NN) = 2.76 TeV. Combined with the Pb-Pb results, our pp analysis is found to be compatible with the interpretation of the a (980) having a tetraquark structure instead of that of a diquark. (C) 2018 Published by Elsevier B.V.Peer reviewe