Infections In Early Childhood Research Articles

Prenatal and early life exposure to air pollution and the risk of severe lower respiratory tract infections during early childhood: the Espoo Cohort Study

BackgroundThere is inconsistent evidence of the effects of exposure to ambient air pollution on the occurrence of lower respiratory tract infections (LRTIs) in early childhood. We assessed the effects of...

Recurrent upper respiratory tract infections in early childhood: a newly defined clinical condition

BackgroundRecurrent Upper Respiratory Tract Infections (R-URTIs) pose a significant challenge in pediatric healthcare, affecting both children and their families. This study aimed to investigate the prevalence, risk factors, and clinical implications of R-URTI in children aged 0–5 years.MethodsThis observational study involved a sample of 483 children aged 0–5 years, focusing on establishing a practical and dynamic definition of R-URTI. Family pediatricians prospectively collected socio-demographic information, medical history, and recorded the occurrence of URTI episodes. Children were followed from recruitment until March 2021, predating the COVID-19 outbreak.ResultsA substantial prevalence of R-URTIs was found, estimating it at 5–10% among this age group. To define R-URTI, a practical and dynamic criterion was proposed: children experiencing a minimum of four URTI episodes, each lasting four days or more, within a six-month period, with intervals of well-being in between.ConclusionsThe study highlighted that specific risk factors for R-URTI were elusive, suggesting that this condition may affect children regardless of their family or clinical history. Moreover, the study’s stratification by age group and times of observation facilitated patient-specific clinical decision-making. The proposed definition may represent a valuable tool for clinicians in diagnosing and addressing R-URTI cases.

Rhinovirus protease cleavage of nucleoporins: perspective on implications for airway remodeling.

Human Rhinoviruses (RV) are a major cause of common colds and infections in early childhood and can lead to subsequent development of asthma via an as yet unknown mechanism. Asthma is a chronic inflammatory pulmonary disease characterized by significant airway remodeling. A key component of airway remodeling is the transdifferentiation of airway epithelial and fibroblast cells into cells with a more contractile phenotype. Interestingly, transforming growth factor-beta (TGF-β), a well characterized inducer of transdifferentiation, is significantly higher in airways of asthmatics compared to non-asthmatics. RV infection induces TGF-β signaling, at the same time nucleoporins (Nups), including Nup153, are cleaved by RV proteases disrupting nucleocytoplasmic transport. As Nup153 regulates nuclear export of SMAD2, a key intermediate in the TGF-β transdifferentiation pathway, its loss of function would result in nuclear retention of SMAD2 and dysregulated TGF-β signaling. We hypothesize that RV infection leads to increased nuclear SMAD2, resulting in sustained TGF-β induced gene expression, priming the airway for subsequent development of asthma. Our hypothesis brings together disparate studies on RV, asthma and Nup153 with the aim to prompt new research into the role of RV infection in development of asthma.

Genotypes predisposing for celiac disease and autoimmune diabetes and risk of infections in early childhood.

Infections in early childhood have been associated with risk of celiac disease (CD) and type 1 diabetes (T1D). We investigated whether this is driven by susceptibility genes for autoimmune disease by comparing infection frequency by genetic susceptibility variants for CD or T1D. We genotyped 373 controls and 384 children who developed CD or T1D in the population-based Norwegian Mother, Father and Child Cohort study (MoBa) study for human leukocyte antigen(HLA)-DQ, FUT2, SH2B3, and PTPN22, and calculated a weighted non-HLA genetic risk score (GRS) for CD and T1D based on over 40 SNPs. Parents reported infections in questionnaires when children were 6 and 18 months old. We used negative binomial regression to estimate incidence rate ratio (IRR) for infections by genotype. HLA genotypes for CD and T1D or non-HLA GRS for T1D were not associated with infections. The non-HLA GRS for CD was associated with a nonsignificantly lower frequency of infections (aIRR: 0.95, 95%CI: 0.87-1.03 per weighted allele score), and significantly so when restricting to healthy controls (aIRR: 0.89, 0.81-0.99). Participants homozygous for rs601338(A;A) at FUT2, often referred to as nonsecretors, had a nonsignificantly lower risk of infections (aIRR: 0.91, 95%CI: 0.83-1.01).SH2B3 and PTPN22 genotypes were not associated with infections. The association between infections and risk of CD (OR: 1.15 per five infections) was strengthened after adjustment for HLA genotype and non-HLA GRS (OR: 1.24). HLA variants and non-HLA GRS conferring susceptibility for CD were not associated with increased risk of infections in early childhood and is unlikely to drive the observed association between infections and risk of CD or T1D in many studies.

IgG Seroreactivites to Viral Capsid Protein VP1 of JC and BK Polyomaviruses in Children at Early Ages with Special Reference to Parental Cofactors.

BK (BKPyV) and JC (JCPyV) polyomaviruses are widespread in humans. Transmission at an early age and the role of parents in spreading these viruses through the family are incompletely understood. Our aim was to determine the seroprevalence of BKPyV and JCPyV in infants at the age of 1, 2, 6, 12, 24, and 36 months and to assess the frequency of BKPyV and JCPyV seroconversion. A variety of maternal and paternal covariates were also tested as potential predictors of these early childhood infections. We used multiplex serology to analyze antibodies to BKPyV and JCPyV from baseline to 3-year follow-up visits. We observed that there was nearly perfect correlation in BKPyV and JCPyV serum IgG antibody levels between the mother-infant pairs during the first year of the infant's life. No correlation among BKPyV antibody titers were found in father-child pairs, whereas JCPyV antibody levels of the father and child had a significant correlation at the 2-year follow-up visit. BKPyV infection may be associated with a child's predisposition to allergy. In conclusion, after the decay of maternal antibodies, children start to develop their own immunity toward BKPyV and JCPyV, and horizontal transmission of infection in the family can occur.

Interferon-beta exposure in-utero and the risk of infections in early childhood.

Knowledge within the field of multiple sclerosis treatment during pregnancy is vital to ensure the most optimal clinical practice. Immunomodulatory treatment in pregnancy could in theory affect the normal development and maturation of the immune system of the fetus with a potential increased risk of infections, consequently. We therefore set out to investigate whether exposure to interferon-beta in utero affected the risk of acquiring infections in early childhood. This retrospective matched cohort study utilized data from the Danish Multiple Sclerosis Registry linked with national Danish registries to identify all children born of mothers with MS in Denmark from 1998 to 2018. The study included 510 children exposed to interferon-beta in utero. The children were matched 1:1 on various of demographic characteristics with children born to mothers with untreated MS and 1:3 with children born to mothers without MS. Each child was followed for up to five years. Using individual-level data, we investigated all-cause mortality, rate of hospital admissions due to infections, and redeemed prescriptions of antibiotics. The primary statistical model applied was a negative binomial regression analysis. We found no differences in childhood mortality, for hospital admissions the rate ratio compared to healthy controls was 0.79 (0.62-1.00). Regarding antibiotic prescriptions, the results were similar (RR 1.00 (0.90-1.11). Furthermore, we found no certain dose-response relationship between interferon-beta exposure duration and hospital admission rate (P=0.47) or redeemed antibiotic prescription (P=0.71). Exposure to interferon-beta during gestation has little to no impact on the risk of acquiring significant infections during the first five years of childhood.

IFNL4 Genotypes and Risk of Childhood Burkitt Lymphoma in East Africa.

Interferon lambda 4 (IFN-λ4) is a novel type-III interferon that can be expressed only by carriers of the genetic variant rs368234815-dG within the first exon of the IFNL4 gene. Genetic inability to produce IFN-λ4 (in carriers of the rs368234815-TT/TT genotype) has been associated with improved clearance of hepatitis C virus (HCV) infection. The IFN-λ4-expressing rs368234815-dG allele (IFNL4-dG) is most common (up to 78%) in West sub-Saharan Africa (SSA), compared to 35% of Europeans and 5% of individuals from East Asia. The negative selection of IFNL4-dG outside Africa suggests that its retention in African populations could provide survival benefits, most likely in children. To explore this hypothesis, we conducted a comprehensive association analysis between IFNL4 genotypes and the risk of childhood Burkitt lymphoma (BL), a lethal infection-associated cancer most common in SSA. We used genetic, epidemiologic, and clinical data for 4,038 children from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) and the Malawi Infections and Childhood Cancer case-control studies. Generalized linear mixed models fit with the logit link controlling for age, sex, country, P. falciparum infection status, population stratification, and relatedness found no significant association between BL risk and 3 coding genetic variants within IFNL4 (rs368234815, rs117648444, and rs142981501) and their combinations. Because BL occurs in children 6-9 years of age who survived early childhood infections, our results suggest that additional studies should explore the associations of IFNL4-dG allele in younger children. This comprehensive study represents an important baseline in defining the health effects of IFN-λ4 in African populations.

A Case of Subacute Sclerosing Panencephalitis: A Myriad of Masquerades on Neuroimaging

Subacute sclerosing panencephalitis (SSPE) is a neurodegenerative disease caused by persisting measles virus (MeV) in the central nervous tissue of the patients. About one in ten thousand children who contract the infection in early childhood develop SSPE. Fulminant SSPE is a rare disease with fatal consequences. Magnetic resonance imaging (MRI) can help in making a diagnosis, but all the possible changes encompassing all stages and their correlation with severity are yet to be described. We report a case of fulminant SSPE with unusual findings on MRI, which led to great difficulty and delay in making the correct diagnosis.

Eosinophil granule proteins as a biomarker in managing asthma and allergies.

In the past few decades, biomarkers have been successfully used for the diagnosis, treatment, and monitoring of disease. Taking together clinical, genetic, lifestyle, and information on relevant biomarkers, the therapy of diseases can be personalized to an individual. Several novel biomarkers have been recently reported for allergic diseases. However, to interpret the validity of biomarker data, the validation of their reliability, precision, and reproducibility is imperative. Once validated, they can be used in therapeutic product development and in clinical practice. Eosinophils are multifunctional leukocytes and major effector cells that play a crucial role in the immunological mechanisms of allergic disease. Measuring eosinophils has been the gold standard for treating and monitoring eosinophil-related diseases such as asthma, atopic dermatitis, and allergic rhinitis. However, eosinophil numbers/percentages yield little information about eosinophil activity. Eosinophil activation leads to the extracellular release of 4 granule proteins, with the most promising biomarker of the 4 being eosinophil-derived neurotoxin (EDN). EDN is more easily recovered from measuring instruments and cell surfaces than other eosinophil biomarkers because of its weaker electrical charge. EDN is known to be released from eosinophils at a greater efficiency, adding to its recoverability. It also has antiviral activity in respiratory infections associated with allergic disease development in early life (eg, respiratory syncytial virus and human rhinovirus infections in early childhood). EDN can be measured in several body fluids, including blood, urine, sputum, nasal secretions, and bronchoalveolar lavage. EDN is a stable biomarker utilized to precisely diagnose, treat, and monitor many eosinophil-related allergic diseases. This eosinophil granule protein may prove useful in precision medicine approaches and should always be considered as a useful tool for the clinician to give the best patient care possible.

Coronavirus spike protein-specific antibodies indicate frequent infections and reinfections in infancy and among BNT162b2-vaccinated healthcare workers

The prevalence of seasonal human coronavirus (HCoV) infections in early childhood and adults has not been well analyzed in longitudinal serological studies. Here we analyzed the changes in HCoV (229E, HKU1, NL63, OC43, MERS, and SARS-CoV-2) spike-specific antibody levels in follow-up serum specimens of 140 children at the age of 1, 2, and 3 years, and of 113 healthcare workers vaccinated for Covid-19 with BNT162b2-vaccine. IgG antibody levels against six recombinant HCoV spike subunit 1 (S1) proteins were measured by enzyme immunoassay. We show that by the age of three years the cumulative seropositivity for seasonal HCoVs increased to 38–81% depending on virus type. BNT162b2 vaccinations increased anti-SARS-CoV-2 S1 antibodies, but no increase in seasonal coronavirus antibodies associated with vaccinations. In healthcare workers (HCWs), during a 1-year follow-up, diagnostic antibody rises were seen in 5, 4 and 14% of the cases against 229E, NL63 and OC43 viruses, respectively, correlating well with the circulating HCoVs. In 6% of the HCWs, a diagnostic antibody rise was seen against S1 of HKU1, however, these rises coincided with anti-OC43 S1 antibody rises. Rabbit and guinea pig immune sera against HCoV S1 proteins indicated immunological cross-reactivity within alpha-CoV (229E and NL63) and beta-CoV (HKU1 and OC43) genera.

Exploring the Complex Associations Between Prenatal and Early-Life Infections and Obsessive-Compulsive and Tic-Related Disorders

An association between rheumatic fever and chorea was first posited at the beginning of the 19th century, but it was not until the mid–19th century that these observations crystalized into a widely accepted understanding that rheumatism caused Sydenham chorea ( 1 Martino D. Tanner A. Defazio G. Church A.J. Bhatia K.P. Giovannoni G. Dale R.C. Tracing Sydenham’s chorea: Historical documents from a British paediatric hospital. Arch Dis Child. 2005; 90: 507-511 Crossref PubMed Scopus (13) Google Scholar ). Advances in diagnostic methods, including the use of the stethoscope to detect cardiac manifestations of rheumatic fever, partially explain this discovery. However, perhaps an even more significant factor was the gradual shift during this period in the locus of medical care from the home to specialized centers, such as children’s hospitals, which led to case-based registries ( 1 Martino D. Tanner A. Defazio G. Church A.J. Bhatia K.P. Giovannoni G. Dale R.C. Tracing Sydenham’s chorea: Historical documents from a British paediatric hospital. Arch Dis Child. 2005; 90: 507-511 Crossref PubMed Scopus (13) Google Scholar ). It was from examination of these registries that British researchers were initially able to show a temporal relationship between seasonal spikes in rheumatic fever and chorea in children. SEE CORRESPONDING ARTICLE ON PAGE 1023 SEE CORRESPONDING ARTICLE ON PAGE 1023 Prenatal and Early Childhood Infections and Subsequent Risk of Obsessive-Compulsive Disorder and Tic Disorders: A Nationwide, Sibling-Controlled StudyBiological PsychiatryVol. 93Issue 11PreviewPostinfectious autoimmune processes are hypothesized to be causally related to both obsessive-compulsive disorder (OCD) and tic disorders, but current evidence is conflicting. This study examined whether prenatal maternal (and paternal, as an internal control) infections and early childhood infections in the offspring (i.e., during the first 3 years of life) were associated with a subsequent risk of OCD and Tourette syndrome or chronic tic disorder (TS/CTD). Full-Text PDF Open Access

Mayer‐Rokitansky‐Küster‐Hauser syndrome presented as recurrent urinary tract infection in childhood (case report)

AbstractBackgroundMayer‐Rokitansky‐Küster‐Hauser syndrome (MRKH) is characterized by the absence of the uterus and upper two‐thirds of the vagina, normal secondary sexual development, and 46XX karyotype is one of the rare types of Mullerian agenesis. There may be associated congenital anomalies in other organ systems especially those with the same embryogenesis such as the urinary tract mostly in its upper parts present in 40% of cases including renal agenesis, ectopic kidney (unilateral or bilateral), renal hypoplasia, horseshoe kidneys, and hydronephrosis. Other organ systems also may be affected such as skeletal and auditory systems. MRKH is diagnosed mostly during or after adolescence because of unexpected amenorrhea or disturbed sexual experiences.Case reportWe present a 3‐year‐old girl coming with recurrent bouts of urinary tract infections diagnosed as having MRKH syndrome established by imaging and genetic studies. Our case is very rare and interesting because it presents itself as a recurrent urinary tract infection in early childhood which is rare and unusual. In this case, early detection helped us to prevent chronic kidney disease and also planning to perform necessary minimal but very important surgical procedures before initiation of sexual activities to relieve the psychosocial aspect of the syndrome both for the child and parents.ConclusionHealth givers should keep in mind that rare syndromes may present as a repeated quite common problem or have confusing or conceiving presentations. This point will assist us in the early detection of rare diseases at an earlier age or stage.

Subacute myoclonic measles encephalitis - An opportunistic HIV-associated infection.

An unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression. This is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania. The presumptive diagnosis of subacute myoclonic measles encephalitis (SMME) was based on: (1) epidemiological data, previous measles episode or presumed contact with measles virus (MV), (2) clinical presentation with initial localized myoclonic jerks with rapid extension and subsequent motor deficit with preserved mental status, and (3) neuroimaging studies revealing cortical gray matter lesions. Definitive diagnosis was based on a neuropathological exam and immunohistochemistry of brain tissues, and measles RNA detection in the cerebrospinal fluid (CSF). Thirty-six patients were diagnosed with a particular form of SME during consecutive measles outbreaks in Romania: 1996-1998 (22); 2005-2008 (12); 2010-2011 (1) and 2016-2018 (1). Most children were born in the late 80s and had parenterally acquired HIV infection in early childhood. Before the episode of SMME, 11 patients had confirmed measles, while the rest, without typical rash, had a respiratory tract infection and/or presumed previous measles contact. In all patients, the clinical onset was sudden, with unilateral myoclonus. MRI findings revealed mainly focal cortical gray matter lesions. Neurologic symptoms progressed rapidly to coma and death in most patients. Three patients survived SMME, they had higher CD4 count at onset, slower progression of neurological symptoms, and benefit of immune recovery with cART. Immunocytochemistry studies revealed MV in the brain with a pattern suggesting an ascending viral neural infection. MV was isolated from CSF in 7 out of 8 patients. Sequence analysis of MV RNA from both nasopharyngeal swabs and CSF was available for one patient with similar N-450 strain characteristics. During an outbreak of measles, neurological manifestations, especially myoclonus in immunosuppressed patients, can be related to measles even in the absence of an acute episode. This particular form of subacute myoclonic measles encephalitis is an opportunistic fatal disease. Immune recovery due to effective antiretroviral treatment might increase survival.

Editorial comment on: Diet‐associated vertically transferred metabolites and risk of asthma, allergy, eczema, and infections in early childhood

The peer review history for this article is available at https://www.webofscience.com/api/gateway/wos/peer-review/10.1111/pai.13947.

Association of Asthma Risk Alleles With Acute Respiratory Tract Infections and Wheezing Illnesses in Young Children.

Genome-wide association studies have identified several risk alleles for early childhood asthma, particularly in the 17q21 locus and in the cadherin-related family member 3 (CDHR3) gene. Contribution of these alleles to the risk of acute respiratory tract infections (ARI) in early childhood is unclear. We analyzed data from the STEPS birth-cohort study of unselected children and the VINKU and VINKU2 studies on children with severe wheezing illness. Genome-wide genotyping was performed on 1011 children. We analyzed the association between 11 preselected asthma risk alleles and the risk of ARIs and wheezing illnesses of various viral etiologies. The asthma risk alleles in CDHR3, GSDMA, and GSDMB were associated with an increased rate of ARIs (for CDHR3, incidence rate ratio [IRR], 1.06; 95% confidence interval [CI], 1.01-1.12; P = .02), and risk allele in CDHR3 gene with rhinovirus infections (IRR, 1.10; 95% CI, 1.01-1.20, P = .03). Asthma risk alleles in GSDMA, GSDMB, IKZF3, ZPBP2, and ORMDL3 genes were associated with wheezing illnesses in early childhood, especially rhinovirus-positive wheezing illnesses. Asthma risk alleles were associated with an increased rate of ARIs and an increased risk of viral wheezing illnesses. Nonwheezing and wheezing ARIs and asthma may have shared genetic risk factors. Clinical Trials Registration. NCT00494624 and NCT00731575.

The Novel ZBTB24 Mutation Identified in an Iranian Patient with Type 2 ICF Syndrome

Autosomal-recessive immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is mainly determined by recurrent tract respiratory and gastrointestinal infections in early childhood due to agammaglobulinemia. Most patients with ICF syndrome die of infection at a young age, usually in the first or second decade of life. The leading cause of ICF disorders is mutations in genes whose products play a role in DNA methylation. ICF syndrome is classified into two groups: type 1 (ICF1) patients have mutations in the DNMT3B gene, and about half of type 2 (ICF2) patients have mutations in the ZBTB24 gene. In this study, we report the case of a 34-year-old female of Iranian consanguineous parents, who was diagnosed at one year of age with ICF-2 syndrome with recurrent infections, mental retardation, and a homozygous novel mutation in the ZBTB24 gene.

Early childhood lower respiratory tract infection and premature adult death from respiratory disease in Great Britain: a national birth cohort study

Lower respiratory tract infections (LRTIs) in early childhood are known to influence lung development and lifelong lung health, but their link to premature adult death from respiratory disease is unclear. We aimed to estimate the association between early childhood LRTI and the risk and burden of premature adult mortality from respiratory disease. This longitudinal observational cohort study used data collected prospectively by the Medical Research Council National Survey of Health and Development in a nationally representative cohort recruited at birth in March, 1946, in England, Scotland, and Wales. We evaluated the association between LRTI during early childhood (age <2 years) and death from respiratory disease from age 26 through 73 years. Early childhood LRTI occurrence was reported by parents or guardians. Cause and date of death were obtained from the National Health Service Central Register. Hazard ratios (HRs) and population attributable risk associated with early childhood LRTI were estimated using competing risks Cox proportional hazards models, adjusted for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and smoking at age 20-25 years. We compared mortality within the cohort studied with national mortality patterns and estimated corresponding excess deaths occurring nationally during the study period. 5362 participants were enrolled in March, 1946, and 4032 (75%) continued participating in the study at age 20-25 years. 443 participants with incomplete data on early childhood (368 [9%] of 4032), smoking (57 [1%]), or mortality (18 [<1%]) were excluded. 3589 participants aged 26 years (1840 [51%] male and 1749 [49%] female) were included in the survival analyses from 1972 onwards. The maximum follow-up time was 47·9 years. Among 3589 participants, 913 (25%) who had an LRTI during early childhood were at greater risk of dying from respiratory disease by age 73 years than those with no LRTI during early childhood (HR 1·93, 95% CI 1·10-3·37; p=0·021), after adjustment for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and adult smoking. This finding corresponded to a population attributable risk of 20·4% (95% CI 3·8-29·8) and 179 188 (95% CI 33 806-261 519) excess deaths across England and Wales between 1972 and 2019. In this prospective, life-spanning, nationally representative cohort study, LRTI during early childhood was associated with almost a two times increased risk of premature adult death from respiratory disease, and accounted for one-fifth of these deaths. National Institute for Health and Care Research Imperial Biomedical Research Centre, Royal Brompton and Harefield National Health Service (NHS) Foundation Trust, Royal Brompton and Harefield Hospitals Charity and Imperial College Healthcare NHS Trust, UK Medical Research Council.

Diet-associated vertically transferred metabolites and risk of asthma, allergy, eczema, and infections in early childhood.

Evidence suggests maternal pregnancy dietary intake and nutrition in the early postnatal period to be of importance for the newborn child's health. However, studies investigating diet-related metabolites transferred from mother to child on disease risk in childhood are lacking. We sought to investigate the influence of vertically transferred metabolites on risk of atopic diseases and infections during preschool age. In the Danish population-based COPSAC2010 mother-child cohort, information on 10 diet-related vertically transferred metabolites from metabolomics profiles of dried blood spots (DBS) at age 2-3 days was analyzed in relation to the risk of childhood asthma, allergy, eczema, and infections using principal component and single metabolite analyses. In 678 children with DBS measurements, a coffee-related metabolite profile reflected by principal component 1 was inversely associated with risk of asthma (odds ratio (95% CI) 0.78 (0.64; 0.95), p=.014) and eczema at age 6 years (0.79 (0.65; 0.97), p=.022). Furthermore, increasing stachydrine (fruit-related), 3-carboxy-4-methyl-5-propyl-2-furanpropanoate (fish-related), and ergothioneine (fruit-, green vegetables-, and fish-related) levels were all significantly associated with reduced risks of infections at age 0-3 years (p < .05). This study demonstrates associations between pregnancy diet-related vertically transferred metabolites measured in children in early life and risk of atopic diseases and infections in childhood. The specific metabolites associated with a reduced disease risk in children may contribute to the characterization of a healthy nutritional profile in pregnancy using a metabolomics-based unbiased tool for predicting childhood health.

First Impressions Matter: Immune Imprinting and Antibody Cross-Reactivity in Influenza and SARS-CoV-2.

Many rigorous studies have shown that early childhood infections leave a lasting imprint on the immune system. The understanding of this phenomenon has expanded significantly since 1960, when Dr. Thomas Francis Jr first coined the term "original antigenic sin", to account for all previous pathogen exposures, rather than only the first. Now more commonly referred to as "immune imprinting", this effect most often focuses on how memory B-cell responses are shaped by prior antigen exposure, and the resultant antibodies produced after subsequent exposure to antigenically similar pathogens. Although imprinting was originally observed within the context of influenza viral infection, it has since been applied to the pandemic coronavirus SARS-CoV-2. To fully comprehend how imprinting affects the evolution of antibody responses, it is necessary to compare responses elicited by pathogenic strains that are both antigenically similar and dissimilar to strains encountered previously. To accomplish this, we must be able to measure the antigenic distance between strains, which can be easily accomplished using data from multidimensional immunological assays. The knowledge of imprinting, combined with antigenic distance measures, may allow for improvements in vaccine design and development for both influenza and SARS-CoV-2 viruses.

Geographically targeted chronic infection screening: lessons from a hepatitis B pilot study in the UK.

Chronic hepatitis B (CHB) most commonly occurs following infection in early childhood. Prevalence varies markedly around the globe. Country of birth is therefore a strong predictor of CHB risk in adults. We used country of birth census data to predict CHB risk and carry out geographically targeted screening in East Yorkshire, UK. Despite engaging individuals born in high-prevalence countries with testing, we observed lower than expected prevalence in targeted highest-risk areas, which may indicate barriers to testing for people with undiagnosed CHB. Improved strategies for engagement with high-risk groups will be key for viral hepatitis elimination.