Initial antigen encounter determines robust T-cell immunity against SARS-CoV-2 BA.2.86 variant three years later.

Objectives: We aimed to evaluate the adaptive immune responses cross-recognition of the hypermutated SARS-CoV-2 BA.2.86 variant and identify the determinants influencing this recognition.

Alterations of the IKZF1-IKZF2 tandem in immune cells of schizophrenia patients regulate associated phenotypes.

Schizophrenia is a complex multifactorial disorder and increasing evidence suggests the involvement of immune dysregulations in its pathogenesis. We observed that IKZF1 and IKZF2, classic immune-related transcription factors (TFs), were both downregulated in patients' peripheral blood mononuclear cells (PBMCs) but not in their brain. We generated a new mutant mouse model with a reduction in Ikzf1 and Ikzf2 to study the impact of those changes.

Identification of Predictors of Shift Work Adaptation and Its Association With Immune, Hormonal and Metabolite Biomarkers.

We explored predictors of shift work adaptation and how it relates to disease risk biomarker levels. These analyses included 38 male, rotating shift workers, sampled twice at the end of a 3-week night shift and a 3-week day shift rotation. Participants collected all 24-h urine voids, wore activity sensors, and responded to questionnaires during each shift.

Mental illness and antibody responses after COVID-19 vaccination in a prospective population-based study in Catalonia.

Unlabelled: Background Mental illnesses have been overlooked as a potential factor influencing antibody responses to COVID-19 vaccine. Associations between mental disorders and antibody response might vary by specific disorders, depend on the long-term course of the illness and relate to psychotropic treatment.

Methods: The association between mental illness diagnoses (mood affective disorders, anxiety disorders, other) over ten years and psychotropic drug prescription based on electronic health records with antibody levels (IgG and IgA) post COVID-19 vaccination was assessed in 939 vaccinated adults from Catalonia, Spain.

Prognostic performance of early immune and endothelial activation markers in mild-to-moderate COVID-19 outpatients: a nested case-control study.

Introduction: Evidence on the association of biomarkers of host response to infection with COVID-19 clinical outcomes has focused mainly on hospitalized patients. We investigated the prognostic performance of 39 immune and endothelial activation markers measured early in the course of disease to predict the development of severe COVID-19 and hospitalization.

Methods: We conducted a nested case-control study from a randomized clinical trial evaluating the efficacy of COVID-19 convalescent plasma in outpatients aged 50 years or older presenting with mild-to-moderate COVID-19.

The association of Helicobacter pylori with adverse pregnancy outcomes in three European birth cohorts.

Background: Helicobacter pylori is a prevalent infection that may complicate pregnancy, but evidence remains limited, controversial and may not apply to all pregnant women.

Objective: This study aims to evaluate whether Helicobacter pylori is a risk factor for adverse pregnancy outcomes and to identify vulnerable subpopulations.

Study Design: Multiplex serology was utilized to measure blood levels of immunoglobulin G against eight Helicobacter pylori antigens in 1372 pregnant women from three European birth cohorts: BiB (United Kingdom), Rhea (Greece) and INMA (Spain).

The effect of Plasmodium falciparum exposure and maternal anti-circumsporozoite protein antibodies on responses to RTS,S/AS01 vaccination in infants and children: an ancillary observational immunological study to a phase 3, randomised clinical trial.

Background: The RTS,S/AS01 malaria vaccine showed lower antibody response and protective efficacy in infants aged 6-12 weeks compared with children aged 5-17 months (for whom this vaccine is recommended). We aimed to study the effect of previous Plasmodium falciparum exposure on the antibody responses to RTS,S/AS01 vaccination in infants and children, and the mediating effect of baseline (including maternal) anti-circumsporozoite protein (CSP) antibodies.

Methods: In this observational study, we included children and infants from six African countries (Burkina Faso, Gabon, Ghana, Kenya, Mozambique, and Tanzania) enrolled in the MAL067 immunology ancillary study of the RTS,S/AS01 phase 3 clinical trial from March 27, 2009, to Jan 21, 2011.

Effect of RTS,S/AS01 vaccine booster dose on cellular immune responses in African infants and children.

RTS,S/AS01, the first approved malaria vaccine, demonstrated moderate efficacy during the phase 3 pediatric trial. We previously investigated cell-mediated immune (CMI) responses following the primary 3-dose immunization and now report responses to the booster dose given 18 months later. Thirty CMI markers were measured by Luminex in supernatants of peripheral blood mononuclear cells from 709 children and infants after RTS,S/AS01 antigen stimulation, and their associations with malaria risk and antibodies one month post-booster and one year later were assessed.

Antibody responses to common viruses according to COVID-19 severity and postacute sequelae of COVID-19.

Limited research suggests that certain viruses reactivate in severe-acute-respiratory-syndrome-coronavirus 2 infection, contributing to the development of postacute sequelae of COVID-19 (PASC). We examined 1083 infected individuals from a population-based cohort, and assessed differences in plasma immunoglobulin (Ig)G and immunoglobulin A levels against Epstein-Barr virus (EBV), cytomegalovirus, varicella zoster virus (VZV), BK polyomavirus, KI polyomavirus, WU polyomavirus (WUPyV), respiratory syncytial virus, and Adv-36 according to the severity of previous COVID-19 and PASC history. Individuals who had experienced severe COVID-19 had higher antibody responses to latent viruses.

Antibody mechanisms of protection against malaria in RTS,S-vaccinated children: a post-hoc serological analysis of phase 2 trial.

Background: The RTS,S malaria vaccine is currently recommended for children aged 5-6 months in regions with moderate-to-high Plasmodium falciparum transmission. However, vaccination only confers 55% efficacy over 12 months and wanes within 18 months. The immunological mechanisms of RTS,S-mediated immunity are poorly understood; therefore, we aimed to identify antibody response types associated with protection against malaria in children vaccinated with RTS,S.

Malaria and other infections induce polyreactive antibodies that impact SARS-CoV-2 seropositivity estimations in endemic settings.

Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence is used to estimate the proportion of individuals within a population previously infected, to track viral transmission, and to monitor naturally and vaccine-induced immune protection. However, in sub-Saharan African settings, antibodies induced by higher exposure to pathogens may increase unspecific seroreactivity to SARS-CoV-2 antigens, resulting in false positive responses. To investigate the level and type of unspecific seroreactivitiy to SARS-CoV-2 in Africa, we measured immunoglobulin G (IgG), IgA, and IgM to a broad panel of antigens from different pathogens by Luminex in 602 plasma samples from African and European subjects differing in coronavirus disease 2019, malaria, and other exposures.

Correlates of protection and determinants of SARS-CoV-2 breakthrough infections 1 year after third dose vaccination.

Background: The emergence of new SARS-CoV-2 variants and the waning of immunity raise concerns about vaccine effectiveness and protection against COVID-19. While antibody response has been shown to correlate with the risk of infection with the original variant and earlier variants of concern, the effectiveness of antibody-mediated protection against Omicron and the factors associated with protection remain uncertain.

Methods: We evaluated antibody responses to SARS-CoV-2 spike (S) and nucleocapsid (N) antigens from Wuhan and variants of concern by Luminex and their role in preventing breakthrough infections 1 year after a third dose of mRNA vaccination, in a cohort of health care workers followed since the pandemic onset in Spain (N = 393).

Evaluation of the accuracy of a multi-infection screening test based on a multiplex immunoassay targeting imported diseases common in migrant populations.

Background: We aimed to evaluate the performance of a novel multiplex serological assay, able to simultaneously detect IgG of six infections, as a screening tool for imported diseases in migrants.

Methods: Six panels of 40 (n = 240) anonymized serum samples with confirmed infections were used as positive controls to assess the multiplex assay's sensitivity. One panel of 40 sera from non-infected subjects was used to estimate the seropositivity cutoffs, and 32 non-infected sera were used as negative controls to estimate each serology's sensitivity and specificity.

RTS,S/AS02A Malaria Vaccine-Induced IgG Responses Equally Recognize Native-Like Fucosylated and Nonfucosylated Plasmodium falciparum Circumsporozoite Proteins.

The RTS,S/AS02A malaria vaccine is based on the Plasmodium falciparum circumsporozoite protein (PfCSP), which is O-fucosylated on the sporozoite surface. We determined whether RTS,S/AS02A-induced immunoglobulin G (IgG) antibodies recognize vaccine-like nonfucosylated PfCSP better than native-like fucosylated PfCSP. Similar to previous vaccine trials, RTS,S/AS02A vaccination induced high anti-PfCSP IgG levels associated with malaria protection.

Associations between prenatal malaria exposure, maternal antibodies at birth, and malaria susceptibility during the first year of life in Burkina Faso.

In this study, we investigated how different categories of prenatal malaria exposure (PME) influence levels of maternal antibodies in cord blood samples and the subsequent risk of malaria in early childhood in a birth cohort study ( = 661) nested within the COSMIC clinical trial (NCT01941264) in Burkina Faso. infections during pregnancy and infants' clinical malaria episodes detected during the first year of life were recorded. The levels of maternal IgG and IgG to 15 .

Prepandemic personal concentrations of per- and polyfluoroalkyl substances (PFAS) and other pollutants: Specific and combined effects on the incidence of COVID-19 disease and SARS-CoV-2 infection.

Objective: To investigate the specific and combined effects of personal concentrations of some per- and polyfluoroalkyl substances (PFAS), other persistent organic pollutants (POPs), and chemical elements -measured in individuals' blood several years before the pandemic- on the development of SARS-CoV-2 infection and COVID-19 disease in the general population.

Methods: We conducted a prospective cohort study in 240 individuals from the general population of Barcelona. PFAS, other POPs, and chemical elements were measured in plasma, serum, and whole blood samples, respectively, collected in 2016-2017.

Long-Term Exposure to Air Pollution and COVID-19 Vaccine Antibody Response in a General Population Cohort (COVICAT Study, Catalonia).

Background: Ambient air pollution has been associated with COVID-19 disease severity and antibody response induced by infection.

Objectives: We examined the association between long-term exposure to air pollution and vaccine-induced antibody response.

Methods: This study was nested in an ongoing population-based cohort, COVICAT, the GCAT-Genomes for Life cohort, in Catalonia, Spain, with multiple follow-ups.

Seroprevalence and socioeconomic impact of the first SARS-CoV-2 infection wave in a small town in Navarre, Spain.

The characterization of the antibody response to SARS-CoV-2 and its determinants are key for the understanding of COVID-19. The identification of vulnerable populations to the infection and to its socioeconomic impact is indispensable for inclusive policies. We conducted an age-stratified cross-sectional community-based seroprevalence survey between June 12th and 19th 2020-during the easing of lockdown-in Cizur, Spain.

Individual blood concentrations of persistent organic pollutants and chemical elements, and COVID-19: A prospective cohort study in Barcelona.

Background: There is wide, largely unexplained heterogeneity in immunological and clinical responses to SARS-CoV-2 infection. Numerous environmental chemicals, such as persistent organic pollutants (POPs) and chemical elements (including some metals, essential trace elements, rare earth elements, and minority elements), are immunomodulatory and cause a range of adverse clinical events. There are no prospective studies on the effects of such substances on the incidence of SARS-CoV-2 infection and COVID-19.

RBD-Based ELISA and Luminex Predict Anti-SARS-CoV-2 Surrogate-Neutralizing Activity in Two Longitudinal Cohorts of German and Spanish Health Care Workers.

The ability of antibodies to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important correlate of protection. For routine evaluation of protection, however, a simple and cost-efficient anti-SARS-CoV-2 serological assay predictive of serum neutralizing activity is needed. We analyzed clinical epidemiological data and blood samples from two cohorts of health care workers in Barcelona and Munich to compare several immunological readouts for evaluating antibody levels that could be surrogates of neutralizing activity.