Tato stránka byla automaticky přeložena a přesnost překladu není zaručena. Podívejte se prosím na anglická verze pro zdrojový text.

Mucosal and Systemic Immunity Correlates of Protection Against Influenza in Young Children, Aged 2-5 Years (MUSIC-Flu) (MUSIC-Flu)

Mucosal and Systemic Immunity Correlates of Protection Against Influenza in Young Children (MUSIC-Flu)

Title: Mucosal and systemic immunity correlates of protection against influenza in young children (MUSIC-Flu). The goal of this observational study is to better understand how immune responses in the blood and mucosa are linked to protection against influenza infection and illness in young children. We will compare immune responses in children who get influenza infection to those who do not.

Children aged 2-5 years of age will be followed from April through October 2026 during the influenza season in South Africa. During this time, nasal swabs will be collected three times per week to test for influenza and other respiratory viruses. Information on symptoms and temperature will be collected by nurses at weekly visits and daily by caregivers using an electronic symptom diary.

Blood samples will be collected before and after the influenza season, and at two additional time points during the study. Special immune cells will also be collected from blood samples before and after the season. In addition, samples from the nose and mouth will be collected every month. These samples will be tested to measure immune responses, including antibodies, signaling proteins (cytokines), and specific immune cells (T cells and B cells).

Přehled studie

Postavení

Nábor

Podmínky

Detailní popis

Annual influenza epidemics cause an estimated 290 000-650 000 deaths globally, with a disproportionately high burden in sub-Saharan Africa. In South Africa, approximately 20% of the population develops influenza-associated illness annually, with the highest rates of severe illness and mortality among infants and the elderly. Children under five years of age show particularly high infection rates (up to 67 per 100 person-seasons) and play a key role in transmission. Pediatric vaccination programmed in high-income countries have shown indirect protection to vulnerable populations, but such strategies are not implemented in sub-Saharan Africa in part because the mechanism for the indirect effects are not well understood and because influenza vaccination is only moderately effective. To elucidate the mechanism through which the indirect effects are acting, such as through reducing transmission, and to develop more effective vaccines, further studies and trials are needed.

Correlates of protection are immune markers that predict if an individual will be protected from infection or illness. For vaccine trials, it is a useful tool to allow for the estimation of immune responses without doing large efficacy trials. For influenza, the commonly accepted correlate of protection, especially for inactivated vaccines, is antibodies against the haemagglutinin surface protein, measured as HAI titers. However, limitations exist with HAI titer as a correlate of protection, particularly in children where higher titers are needed for protection compared to adults. More recent research has suggested promise that mucosal immune markers may better correlate with influenza infection and illness, as this is where the infection begins, but these markers have not yet been fully identified or described. In this study we aim to identify additional correlates of protection/infection, including mucosal correlates, to provide essential evidence to inform vaccine development, regulatory pathways, and implementation strategies aimed at reducing influenza transmission and disease burden in South Africa and other similar settings.

Aim:

To describe and compare humoral and cellular immune responses to natural influenza virus infection in the mucosa and blood to identify possible correlates of protection against influenza infection, illness and duration of virus shedding.

Primary objectives:

In children aged 2-5 years:

  1. Characterize mucosal and systemic immune markers profiles among children with and without PCR- and/or serologically-confirmed naturally acquired influenza infection
  2. Characterize mucosal and systemic immune marker profiles among children with and without PCR-confirmed naturally acquired influenza-associated illness
  3. Characterize how natural infection-induced mucosal and systemic immune markers may correlate with reduction in viral load and duration of shedding during influenza infection Secondary objectives

1. Determine whether immune markers that correlate with protection against infection also correlate with protection against illness and with reduction in viral load/duration of shedding 2. Assess the impact of respiratory viral co-infection between influenza virus and RSV or SARS-CoV-2 on influenza presentation, viral load, duration of shedding, and on the magnitude/direction of mucosal/systemic immune responses 3. Quantify the waning of naturally-induced mucosal and systemic immunity over time and estimate the half-life of immune markers 4. Evaluate seroconversion and boosting rates following PCR-confirmed infection and correlate these with mucosal markers 5. Utilize mathematical modelling to define the optimal target product profiles for pediatric transmission-reducing vaccines capable of significantly lowering influenza burden in all ages 6. In a subset of participants: 6.1. Describe how cellular immunity markers (CD4+, CD8+ T cells) from mucosa and periphery correlate with 6.1.1. Protection against PCR- and/or serologically-confirmed influenza infection 6.1.2. Protection against PCR-confirmed influenza illness 6.1.3. Duration of shedding and viral load during PCR-confirmed influenza infection 6.2. Describe the kinetics of cellular immunity (CD4+ and CD8+ T cells)

Methods:

Study design: Prospective, non-interventional, cohort study. Study site and population: The study will be conducted in Jouberton in the North West Province of South Africa, which was the site of previous studies of community influenza and SARS-CoV-2 transmission (PHIRST and PHIRST-C) and an intensive cohort study among toddlers that estimated the incidence of influenza infection (ISiT). Enrolled participants will be healthy children aged 2-5 years, resident in Jouberton and available for follow up for the duration of the study.

Sample size: We will enrol a maximum of 150 children, which even if loss to follow-up reaches close to 30% and the final sample size is 100, will provide 80% power to detect a 50% protection with an influenza attack rate of 45%.

Enrolment and follow up: We will enrol healthy children at clinics in Jouberton, attending for Expanded Progamme of Immunization (EPI) vaccination or other well-child visits. Children aged 2-5 years will be pre-screened and those meeting enrolment criteria will be formally enrolled at the clinic following written informed consent from a parent.

Potential participants will be evaluated for study eligibility and eligible children with caregiver consent will be enrolled and baseline data collected from March through April 2026.

Children will be followed from April through October 2026 during the influenza season. Follow-up includes collection of thrice weekly mid-turbinate nasal swabs to be tested by reverse transcription polymerase chain reaction (RT-PCR) for influenza and other respiratory viruses. One swab per week will be collected by study nurses during a household visit, and two additional swabs per week will be collected by the caregiver. Data on symptoms and tympanic temperature will be collected by nurses at weekly visits and daily by caregivers using an electronic symptom diary. Serum will be collected before and after the season, and at two additional time points during the follow-up period. Peripheral blood mononuclear cells (PBMCs) will be collected before and after the season, and nasal mucosal fluid, oral fluid and nasopharyngeal swabs will be collected monthly to test for immunological markers, including antibodies, cytokines and T- and B-cells.

Analysis: To explore how mucosal and systemic immune markers correlate with protection against influenza infection, illness and virus shedding, we will summaries and compare marker levels between groups with and without influenza infection using geometric means and regression modelling.

Typ studie

Pozorovací

Zápis (Odhadovaný)

150

Kontakty a umístění

Tato část poskytuje kontaktní údaje pro ty, kteří studii provádějí, a informace o tom, kde se tato studie provádí.

Studijní kontakt

  • Jméno: Cheryl Cohen, MBBCh, FCPath(SA) Micro, PhD
  • Telefonní číslo: +27 11 3866593
  • E-mail: cherylc@nicd.ac.za

Studijní záloha kontaktů

  • Jméno: Jackie Kleynhans, MSc, MPH, PhD
  • Telefonní číslo: +27 11 5550383
  • E-mail: jackiel@nicd.ac.za

Studijní místa

    • North West
      • Jouberton, North West, Jižní Afrika, 2193
        • Nábor
        • Peri Natal HIV Research Unit
        • Kontakt:
        • Kontakt:
          • Jocelyn Moyes, MBBch, Msc (Med)
          • Telefonní číslo: +27 828832044
          • E-mail: jocelynm@nicd.ac.za

Kritéria účasti

Výzkumníci hledají lidi, kteří odpovídají určitému popisu, kterému se říká kritéria způsobilosti. Některé příklady těchto kritérií jsou celkový zdravotní stav osoby nebo předchozí léčba.

Kritéria způsobilosti

Věk způsobilý ke studiu

2 roky až 5 let (Dítě)

Přijímá zdravé dobrovolníky

Ano

Pohlaví způsobilá ke studiu

Všechno

Metoda odběru vzorků

Vzorek nepravděpodobnosti

Studijní populace

All health children aged 2 -5 years of age, residing in the Jouberton Township

Popis

Inclusion Criteria:

  • Children aged 2-5 years of age (i.e. from the second birthday until 5 years and 11 months of age) at the time of enrolment.

    • Healthy children as established by medical history and clinical examination before entering the study.
    • Parent availability and willingness to provide written informed consent to all study procedures
    • Child planning to reside in the selected community for the duration of the study.

Exclusion Criteria:

  • Presence of malnutrition (defined as z score for age <-2 based on WHO child grown standard at time of screening for eligibility).

    • Presence of any serious systemic disorder determined by medical history and/or physical examination that would compromise the participant's health or is likely to result in non-conformance to the protocol or a child who is on treatment for any chronic medical condition.
    • Prior history of receiving influenza vaccination.
    • Not providing consent for storage and shipment of samples for immunological testing.
    • Parent of participating child not able, available or willing to accept active weekly follow-up by the study staff, performing a twice-weekly caregiver swab and completing symptom diary on an electronic device or any medical condition in the parents that, in the judgment of the investigator, would interfere with or serves as a contraindication to protocol adherence or a parent's ability to give informed consent. History of chronic administration (defined as more than 14 days) of immunosuppressant medications, including corticosteroids, in the last 6 months (those on inhaled or topical steroids may be permitted to participate in the study.
    • Child is HIV-infected as identified by self-report or if screening of study eligibility identifies that the child is HIV-infected.

Studijní plán

Tato část poskytuje podrobnosti o studijním plánu, včetně toho, jak je studie navržena a co studie měří.

Jak je studie koncipována?

Detaily designu

  • Observační modely: COHORT
  • Časové perspektivy: PROSPECTIVE

Kohorty a intervence

Skupina / kohorta
Health children aged 2-5 years

Observational

Co je měření studie?

Primární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Geometric Mean Titers (GMT) (with 95% CIs) of systemic and mucosal immune markers at each scheduled time point, stratified by infection status (infected vs uninfected) Immune markers include systemic (neutralizing, hemagglutinin, IgM, and IgG) and mucosa
Časové okno: Time frame is at 2, 4 and 6 months of follow-up
Time frame is at 2, 4 and 6 months of follow-up
Time to first laboratory-confirmed influenza infection Association between immune marker levels and time to first influenza infection will be estimated using Cox proportional hazards regression, reported as hazard ratios with 95% confidence intervals.
Časové okno: From start of follow-up until the first RT-PCR-confirmed infection or the end of follow-up in October 2026, whichever occurs first, assessed up to 6 months
From start of follow-up until the first RT-PCR-confirmed infection or the end of follow-up in October 2026, whichever occurs first, assessed up to 6 months
Geometric Mean Titers (GMT) (with 95% CIs) of systemic and mucosal immune markers at each scheduled time point, stratified by PCR-confirmed influenza-like illness (ILI) status (symptomatic ILI infected vs symptomatic ILI uninfected)
Časové okno: At each study sample collection time point (monthly) and then the end of the follow-up period, 6 months from the start of the influenza season (April 2026)

Immune markers include systemic (neutralizing, hemagglutinin, IgM, and IgG) and mucosal (IgM, IgG, and IgA) anti-influenza antibodies.

At each study sample collection time point (monthly) and then the end of the follow-up period, 6 months from the start of the influenza season (April 2026)
Time to first laboratory-confirmed influenza illness Association between baseline immune marker levels and time to first influenza illness will be estimated using Cox proportional hazards regression, reported as hazard ratios with 95% confidence interval
Časové okno: From start of follow-up until the first symptomatic RT-PCR-confirmed influenza episode or the end of follow-up in October 2026, whichever occurs first, assessed up to 6 months
From start of follow-up until the first symptomatic RT-PCR-confirmed influenza episode or the end of follow-up in October 2026, whichever occurs first, assessed up to 6 months
Median Viral Load Median influenza viral load (e.g., log10 copies/mL or Ct-derived quantitative estimate) among participants with ≥1 influenza-positive RT-PCR swab during follow-up.
Časové okno: From the first influenza-positive RT-PCR result until the last positive RT-PCR result during the infection episode, assessed during follow-up through October 2026, up to 6 months from the start of follow-up
From the first influenza-positive RT-PCR result until the last positive RT-PCR result during the infection episode, assessed during follow-up through October 2026, up to 6 months from the start of follow-up
Duration of Viral Shedding Number of days of RT-PCR positivity among participants with ≥1 influenza-positive swab during follow-up
Časové okno: Starting from the first follow-up visit, time to first influenza-positive RT-PCR to last positive RT-PCR during infection episode for each influenza episode(separated by 14 days) to the end of the six month follow-up period.
Starting from the first follow-up visit, time to first influenza-positive RT-PCR to last positive RT-PCR during infection episode for each influenza episode(separated by 14 days) to the end of the six month follow-up period.
Duration of Viral Shedding Number of days of RT-PCR positivity among participants with ≥1 influenza-positive swab during follow-up
Časové okno: From the first influenza-positive RT-PCR result until the last positive RT-PCR result during the infection episode, assessed through the end of follow-up in October 2026, up to 6 months from the start of follow-up.
From the first influenza-positive RT-PCR result until the last positive RT-PCR result during the infection episode, assessed through the end of follow-up in October 2026, up to 6 months from the start of follow-up.

Spolupracovníci a vyšetřovatelé

Zde najdete lidi a organizace zapojené do této studie.

Sponzor

Spolupracovníci

Vyšetřovatelé

  • Vrchní vyšetřovatel: Cheryl Cohen, MBBCh, FCPath(SA) Micro, PhD
  • Vrchní vyšetřovatel: Jackie Kleynhans Kleynhans, MSc, MPH, PhD, National Institute for Communicable Disease

Publikace a užitečné odkazy

Osoba odpovědná za zadávání informací o studiu tyto publikace poskytuje dobrovolně. Mohou se týkat čehokoli, co souvisí se studiem.

Obecné publikace

  • https://crdm.nicd.ac.za/wp-content/uploads/2026/04/MUSIC-Flu-Protocol-v3-20260206-Appvd-20260225-Inc-ICF-Apx.pdf

Termíny studijních záznamů

Tato data sledují průběh záznamů studie a předkládání souhrnných výsledků na ClinicalTrials.gov. Záznamy ze studií a hlášené výsledky jsou před zveřejněním na veřejné webové stránce přezkoumány Národní lékařskou knihovnou (NLM), aby se ujistily, že splňují specifické standardy kontroly kvality.

Hlavní termíny studia

Začátek studia (Aktuální)

12. března 2026

Primární dokončení (Odhadovaný)

31. října 2026

Dokončení studie (Odhadovaný)

31. října 2026

Termíny zápisu do studia

První předloženo

8. dubna 2026

První předloženo, které splnilo kritéria kontroly kvality

2. října 2026

První zveřejněno (Aktuální)

6. října 2026

Aktualizace studijních záznamů

Poslední zveřejněná aktualizace (Aktuální)

6. října 2026

Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality

2. října 2026

Naposledy ověřeno

1. října 2026

Více informací

Termíny související s touto studií

Další identifikační čísla studie

  • MUSIC-Flu
  • IP24-017/ 6 U01IP001269-02-01 (Jiný identifikátor: Centers for Disease Control and Prevention, Atlanta, USA)

Plán pro data jednotlivých účastníků (IPD)

Plánujete sdílet data jednotlivých účastníků (IPD)?

NE

Popis plánu IPD

Demographic, virological, and immunological data will be shared with collaborating laboratories and investigators involved in testing study specimens. All data will be shared in an anonymized format, identified only by study and sample identification numbers. No personal identifying information, such as participant or caregiver names, surnames, contact details, or any other identifiers, will be shared. The child's date of birth will not be shared; instead, only age in months at enrolment will be provided for analytical purposes.

Informace o lécích a zařízeních, studijní dokumenty

Studuje lékový produkt regulovaný americkým FDA

Ne

Studuje produkt zařízení regulovaný americkým úřadem FDA

Ne

Tyto informace byly beze změn načteny přímo z webu clinicaltrials.gov. Máte-li jakékoli požadavky na změnu, odstranění nebo aktualizaci podrobností studie, kontaktujte prosím register@clinicaltrials.gov. Jakmile bude změna implementována na clinicaltrials.gov, bude automaticky aktualizována i na našem webu .