Asthma, Immunity, Respiratory Infection
Conditions
Keywords
Childhood Immunity, Immune Development, Infectious Disease Surveillance, asthma, respiratory infection
Brief summary
This prospective observational study will enroll approximately 1,200 children from birth through 7 years of age in Zhejiang Province, China. Participants will include general healthy children from the community, children with a history of serious or recurrent infections, and children with confirmed or highly suspected asthma. No treatment will be assigned by the researchers. Health information will be collected through questionnaires, vaccination and medical records, regular follow-up, and active surveillance of respiratory infections. Blood, stool, and nasopharyngeal swab samples will be collected at enrollment and annual visits. Additional blood and respiratory samples will be collected during selected respiratory infection events. Laboratory assessments may include antibody, pathogen, microbiome, and single-cell analyses. The study aims to characterize biomarkers of anti-infective immunity in children and assess their risk of infection. Xiamen University, Zhejiang Provincial Center for Disease Control and Prevention, and Xiang An Biomedicine Laboratory are the co-sponsors of this study. Hanqing He (Zhejiang Provincial CDC) and Tianying Zhang (Xiamen University) serve as the co-principal investigators.
Detailed description
This prospective observational cohort study combines scheduled longitudinal assessments, active surveillance of respiratory infections, healthcare data linkage, and biospecimen-based laboratory analyses to characterize biomarkers of anti-infective immunity in children and assess their risk of infection. Questionnaire data and biological samples will be collected at baseline and annual visits. Respiratory infection events will be monitored through regular contact with participants' families, voluntary symptom reporting, sentinel hospital surveillance, and available healthcare records. Remote follow-up will generally occur every 8 to 12 weeks and may increase to every 4 weeks during periods of increased respiratory pathogen activity. Eligible respiratory infection events will trigger acute-phase sampling, preferably within 3 days after illness onset or at the initial clinical visit, and recovery-phase sampling at 21 ± 4 days after onset. All eligible respiratory infection-related hospitalizations will trigger sampling. Outpatient or emergency department events may trigger sampling no more than twice per participant per year, with an interval of at least 6 weeks between events. Laboratory assessments may include vaccine- and pathogen-specific antibodies, respiratory pathogen detection, cytokines, gut microbiome analysis, genomic analysis, and selected single-cell analyses.
Interventions
None listed
Sponsors
Zhejiang Provincial Center for Disease Control and Prevention
Xiamen University
Xiang An Biomedicine Laboratory
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
0 Days to 7 Years
Healthy volunteers
Yes
Inclusion criteria
* Children from birth through 7 years of age (younger than 8 years at enrollment). * The participant's parent or legal guardian is able to understand the study, voluntarily agrees to participation, and provides written informed consent. * The participant resides in the study area and is expected to be available for long-term follow-up. * For the General Community Cohort: no known serious underlying disease before enrollment. * For the Infection Observation Cohort: either a history of hospitalization for an infectious disease before 3 years of age, with documented information on the pathogen, infection site, or clinical diagnosis; or at least three healthcare visits for respiratory infections during the 12 months before enrollment. * For the Childhood Asthma Cohort: physician-confirmed asthma or highly suspected asthma according to the protocol-defined age-specific criteria. Children younger than 1 year will not be included in this cohort.
Exclusion criteria
* An acute illness within 14 days before enrollment, including respiratory, gastrointestinal, dermatologic, or urinary symptoms or conditions specified in the protocol. * Known primary immunodeficiency, malignant tumor, serious congenital disorder, or another condition that may substantially alter immune status. * Long-term use of immunosuppressive or other immunomodulatory medications, defined as continuous or intermittent use for a cumulative duration of at least 3 months. * A diagnosed coagulation abnormality or bleeding disorder, including coagulation factor deficiency, other coagulation disorders, or platelet abnormalities. * Any other condition that, in the investigator's judgment, makes the child unsuitable for participation.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory infection-related healthcare visit or hospitalization events | From enrollment through 48 months | Multiplex respiratory pathogen PCR assay |
| Transcriptional profiles of peripheral blood mononuclear cells (PBMCs) | Baseline, 12, 24, 36 and 48 months | Single-cell RNA sequencing and analysis will be performed on PBMCs collected at the annual study visits. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Vaccine-induced antibody response | Baseline and 12, 24, 36, and 48 months | Antibody levels against hepatitis B, pertussis, and varicella vaccine antigens will be measured in samples collected at the annual study visits. |
| Antibody levels against respiratory pathogens | Baseline and 12, 24, 36, and 48 months | Respiratory syncytial virus (RSV) neutralizing antibodies, Humanmetapneumovirus (HMPV) neutralizing antibodies, Parainfluenza virus (PIV) neutralizing antibodies, and Mycoplasma pneumoniae IgG will be measured in samples collected at the annual study visits. |
| Gut Microbiome Diversity | Baseline and 12, 24, 36, and 48 months | Metagenomic sequencing will be performed on stool samples collected at the annual study visits. |
Countries
China
Contacts
CONTACTHanqing He, PhD
CONTACTTianying Zhang, PhD
STUDY_CHAIRJun Zhang, Master
Xiamen University
PRINCIPAL_INVESTIGATORHanqing He, PhD
Zhejiang Provincial Center for Disease Control and Prevention
PRINCIPAL_INVESTIGATORTianying Zhang, PhD
Xiamen University
Outcome results
None listed