Humoral and cellular immune responses in vaccinated and unvaccinated children following SARS-CoV-2 Omicron infection.

Objectives: The immune response in children elicited by SARS-CoV-2 Omicron infection alone or in combination with COVID-19 vaccination (hybrid immunity) is poorly understood. We examined the humoral and cellular immune response following SARS-CoV-2 Omicron infection in unvaccinated children and children who were previously vaccinated with COVID-19 mRNA vaccine.

Methods: Participants were recruited as part of a household cohort study conducted during the Omicron predominant wave (Jan to July 2022) in Victoria, Australia.

The role of respiratory syncytial virus G protein in immune cell infection and pathogenesis.

Severe respiratory syncytial virus (RSV) disease is a significant contributor to the global burden of disease in infants and children. The RSV attachment protein (G) has been shown to be critical in invading airway epithelial cells through its CX3C motif interacting with the host receptor CX3CR1. The ubiquitous expression of this receptor on immune cells may explain their susceptibility to RSV infection.

Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015-2021.

Background: Data available for RSV and influenza infections among children < 2 years in Mongolia are limited. We present data from four districts of Ulaanbaatar from April 2015 to June 2021.

Methods: This study was nested in an enhanced surveillance project evaluating pneumococcal conjugate vaccine (PCV13) impact on the incidence of hospitalized lower respiratory tract infections (LRTIs).

Impact of pneumococcal conjugate vaccine 13 introduction on severe lower respiratory tract infections associated with respiratory syncytial virus or influenza virus in hospitalized children in Ulaanbaatar, Mongolia.

Objectives: Limited data indicate a beneficial effect of pneumococcal conjugate vaccines (PCVs) on respiratory syncytial virus (RSV) and influenza infections in young children. We evaluated the impact of 13-valent PCV (PCV13) introduction on the incidence of severe lower respiratory tract infections (LRTIs) associated with RSV or influenza in hospitalized children.

Methods: Our study was restricted to children aged <2 years with arterial oxygen saturation <93% and children with radiologically confirmed pneumonia nested in a pneumonia surveillance project in four districts of Ulaanbaatar city, Mongolia.

Differential anti-viral response to respiratory syncytial virus A in preterm and term infants.

Background: Preterm infants are more likely to experience severe respiratory syncytial virus (RSV) disease compared to term infants. The reasons for this are multi-factorial, however their immature immune system is believed to be a major contributing factor.

Methods: We collected cord blood from 25 preterm (gestational age 30.

Aerosol Delivery of Palivizumab in a Neonatal Lamb Model of Respiratory Syncytial Virus Infection.

(1) Background: Palivizumab has been an approved preventative monoclonal antibody for respiratory syncytial virus (RSV) infection for over two decades. However, due to its high cost and requirement for multiple intramuscular injections, its use has been limited mostly to high-income countries. Following our previous study showing the successful lung deposition of aerosolised palivizumab in lambs, this current study evaluated the "proof-of-principle" effect of aerosolised palivizumab delivered as a therapeutic to neonatal lambs following RSV infection.

Estimating the economic burden of respiratory syncytial virus infections in infants in Vietnam: a cohort study.

Background: Little information is available on the costs of respiratory syncytial virus (RSV) in Vietnam or other low- and middle-income countries. Our study estimated the costs of LRTIs associated with RSV infection among children in southern Vietnam.

Methods: We conducted a prospective cohort study evaluating household and societal costs associated with LRTIs stratified by RSV status and severity among children under 2 years old who sought care at a major pediatric referral hospital in southern Vietnam.

Understanding the increased susceptibility to asthma development in preterm infants.

Preterm birth is associated with aberrant pulmonary development and increased susceptibility to a range of chronic lung diseases. Even in healthy preterms, the prevalence of physician-diagnosed asthma is far higher than in infants born at term. While physiological, environmental, and genetic factors have been studied extensively, few studies have investigated the immunological factors underpinning this increased susceptibility.

Comparison of antibody responses to SARS-CoV-2 variants in Australian children.

There is limited understanding of antibody responses in children across different SARS-CoV-2 variants. As part of an ongoing household cohort study, we assessed the antibody response among unvaccinated children infected with Wuhan, Delta, or Omicron variants, as well as vaccinated children with breakthrough Omicron infection, using a SARS-CoV-2 S1-specific IgG assay and surrogate virus neutralization test (% inhibition). Most children infected with Delta (100%, 35/35) or Omicron (81.

Two new dimethylpyranoflavanones from the roots of .

Two previously unreported dimethylpyranoflavanones, pyronomelodorones A and B ( and ), along with five known compounds, 7--methyldihydrowogonin (), 5,6,7-trimethoxyflavanone (), 5,6-dihydroxy-7-methoxy-dihydroflavone (), 5,7,8-trimethoxydihydroflavone (), and pinostrobin (), were isolated from the roots of The structures of all isolates were fully characterized using spectroscopic data and comparison with the previous literature. All isolates were evaluated for their -glucosidase inhibition and their cytotoxicity against KB, HepG2, and MCF7 cell lines. Among the isolates, compound exhibited the most inhibitory activity against -glucosidase and was superior to the positive control with an IC value of 1.

SARS-CoV-2 infection in children and implications for vaccination.

The COVID-19 pandemic caused by novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for more than 500 million cases worldwide as of April 2022. Initial estimates in 2020 found that children were less likely to become infected with SARS-CoV-2 and more likely to be asymptomatic or display mild COVID-19 symptoms. Our early understanding of COVID-19 transmission and disease in children led to a range of public health measures including school closures that have indirectly impacted child health and wellbeing.

Placoisoflavones A and B, two new cytotoxic isoflavonoids from N.D.Khôi & Yakovlev.

Two previously unreported isoflavonoids, placoisoflavones A and B ( and ), along with five known compounds, calopogonium isoflavone B (), jamaicin (), 6-methoxycalopogonium isoflavone A (), vestitol (), and caviunin () have been isolated from the stems of N.D.Khôi & Yakovlev.

New Benzil and Isoflavone Derivatives with Cytotoxic and NO Production Inhibitory Activities from .

The phytochemical investigation of stems led to the isolation of a new isoflavone derivative () and three new benzil derivatives (-), together with four known pyranoisoflavones (-). The structures of all isolated compounds were determined on the basis of extensive spectroscopic analyses, including NMR and HRMS spectral data, as well as comparison of their spectroscopic data with those reported in the literature. The cytotoxicity of all isolated compounds was assessed against the human liver hepatocellular carcinoma (Hep G2) cell line, and compound displayed the most significant cytotoxicity with an IC value of 8.

New Flavonoid Derivatives from and Their α-Glucosidase Inhibitory and Cytotoxic Activities.

Three new flavonoid derivatives, melodorones A-C (-), together with four known compounds, tectochrysin (), chrysin (), onysilin (), and pinocembrin (), were isolated from the stem bark of Their structures were determined on the basis of extensive spectroscopic methods, including NMR and HRESIMS, and by comparison with the literature. Compounds - were evaluated for their in vitro α-glucosidase inhibition and cytotoxicity against KB, Hep G2, and MCF7 cell lines. Among them, compound exhibited the best activity against -glucosidase and was superior to the positive control with an IC value of 2.

A case report describing the immune response of an infant with congenital heart disease and severe COVID-19.

Background: Children with SARS-CoV-2 infection generally present with milder symptoms or are asymptomatic in comparison with adults, however severe disease occurs in a subset of children. To date, the immune correlates of severe COVID-19 in young children have been poorly characterised.

Methods: We report the kinetics of immune responses in relation to clinical and virological features in an infant with acute severe COVID-19 using high-dimensional flow cytometry and multiplex cytokine analysis.

Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis.

Background: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infection in young children. We previously estimated that in 2015, 33·1 million episodes of RSV-associated acute lower respiratory infection occurred in children aged 0-60 months, resulting in a total of 118 200 deaths worldwide. Since then, several community surveillance studies have been done to obtain a more precise estimation of RSV associated community deaths.

Comparison of Seroconversion in Children and Adults With Mild COVID-19.

Importance: The immune response in children with SARS-CoV-2 infection is not well understood.

Objective: To compare seroconversion in nonhospitalized children and adults with mild SARS-CoV-2 infection and identify factors that are associated with seroconversion.

Design, Setting, And Participants: This household cohort study of SARS-CoV-2 infection collected weekly nasopharyngeal and throat swabs and blood samples during the acute (median, 7 days for children and 12 days for adults [IQR, 4-13] days) and convalescent (median, 41 [IQR, 31-49] days) periods after polymerase chain reaction (PCR) diagnosis for analysis.

Can early measles vaccination control both measles and respiratory syncytial virus infections?

Measles virus and respiratory syncytial virus (RSV) are two important global health pathogens causing substantial morbidity and mortality worldwide. The current measles vaccination schedule has the first dose given at 9-12 months of age and the second dose given at 15-18 months of age. Measles outbreaks have been associated with an increase in severe RSV infections in children younger than 6 months, probably as a result of measles-induced immunosuppression.

Immune Profiling of Cord Blood From Preterm and Term Infants Reveals Distinct Differences in Pro-Inflammatory Responses.

Background: Preterm infants are highly vulnerable to infectious disease. While many factors are likely to contribute to this enhanced susceptibility, the immature nature of the preterm immune system is postulated as one key factor.

Methods: In our study, we used high-dimensional flow cytometry and cytokine assays to characterise the immune profiles in 25 preterm (range: 30.

Children and Adults in a Household Cohort Study Have Robust Longitudinal Immune Responses Following SARS-CoV-2 Infection or Exposure.

Children have reduced severity of COVID-19 compared to adults and typically have mild or asymptomatic disease. The immunological mechanisms underlying these age-related differences in clinical outcomes remain unexplained. Here, we quantify 23 immune cell populations in 141 samples from children and adults with mild COVID-19 and their PCR-negative close household contacts at acute and convalescent time points.

The effects of the dietary compound L-sulforaphane against respiratory pathogens.

L-sulforaphane (LSF) is an isothiocyanate derived from cruciferous vegetables that has long been known for its anticarcinogenic, antioxidant and anti-inflammatory effects. LSF also possesses antimicrobial properties, although the evidence for this is limited. Respiratory pathogens, such as Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes and respiratory syncytial virus (RSV), are leading global causes of illness and death among children aged under five years, particularly in resource-poor countries where access to vaccines are limited or, in the case of S.