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Assessing Vaccine Effectiveness of R21/Matrix-M Across Malaria Transmission Settings (AVERT) (AVERT)

3 agosto 2026 aggiornato da: Clinton Health Access Initiative Inc.

Real-World Effectiveness of the R21/Matrix-M Malaria Vaccine in Children in Burkina Faso and Uganda

The AVERT study is a prospective observational test-negative case control study evaluating the real-world effectiveness of the R21/Matrix-M malaria vaccine among children younger than 5 years in Burkina Faso and Uganda. Children who seek outpatient care with suspected malaria and are eligible for the national R21/Matrix-M vaccination program will be enrolled. Malaria infection will be determined by blood smear microscopy. Children with a positive microscopy result will be classified as cases and children with a negative result as controls. Vaccination history, including the number and timing of doses, will be obtained primarily from vaccination cards or other written records. Vaccine effectiveness will be estimated by comparing the odds of vaccination among cases and controls.

Panoramica dello studio

Stato

Reclutamento

Condizioni

Intervento / Trattamento

Descrizione dettagliata

R21/Matrix-M has been introduced through national immunization programs, but its effectiveness under routine conditions may differ from efficacy observed in clinical trials because children may receive different numbers of doses, doses may be delayed, protection may wane, and malaria transmission and other prevention measures vary across settings.

AVERT will use a prospective test-negative case-control design at approximately 22 outpatient health facilities in moderate- to high-transmission areas of Burkina Faso and Uganda. Consecutive children younger than 5 years who meet country definitions for suspected malaria, are eligible for R21/Matrix-M vaccination, and have caregiver consent will be enrolled. All participants will undergo malaria testing as part of routine care, with study blood smear microscopy used to assign case or control status. A structured caregiver questionnaire will collect demographic, clinical, residential, socioeconomic, health-care access, and malaria-prevention information. R21/Matrix-M dose number and vaccination dates will be verified primarily from vaccination cards, individual health records, or facility vaccination registers.

Cases and controls will be matched, when feasible, by geographic area and calendar time. Conditional or standard logistic regression will estimate adjusted odds ratios comparing vaccinated and unvaccinated children, and vaccine effectiveness will be calculated as (1 - adjusted odds ratio) x 100%. Analyses will be conducted separately by country and will assess effectiveness by dose, time since vaccination, dose spacing, transmission intensity, sex, and use of seasonal malaria chemoprevention, insecticide-treated nets, and indoor residual spraying. A health-system-perspective economic evaluation will estimate incremental cost per uncomplicated clinical malaria case averted.

Tipo di studio

Osservativo

Iscrizione (Stimato)

20000

Contatti e Sedi

Questa sezione fornisce i recapiti di coloro che conducono lo studio e informazioni su dove viene condotto lo studio.

Luoghi di studio

  • Burkina Faso
    • Boucle Mouhoun
      • Boromo, Boucle Mouhoun, Burkina Faso
        • Reclutamento
        • Boromo urbain 1
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Boromo, Boucle Mouhoun, Burkina Faso
        • Reclutamento
        • Ouahabou
        • Contatto:
          • h Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
    • Hauts-Bassins Region
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Béréba
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Dohoun
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Kari
        • Contatto:
          • Halidou Tinto
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Déguélin
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Karangasso-Vigué
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Sourmousso
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Reclutamento
        • Wara
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
    • Oubri
      • Zorgo, Oubri, Burkina Faso
        • Reclutamento
        • Mankarga T
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Zorgo, Oubri, Burkina Faso
        • Reclutamento
        • Mankarga V3
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
      • Zorgo, Oubri, Burkina Faso
        • Reclutamento
        • Mankarga V6
        • Contatto:
          • Halidou Tinto, PhD
          • Numero di telefono: +226 25 40 92 12
          • Email: tintoh@crun.bf
  • Uganda
    • Acholi
      • Kitgum, Acholi, Uganda
        • Non ancora reclutamento
        • Kitgum-Matidi HCIII
        • Contatto:
      • Kitgum, Acholi, Uganda
        • Non ancora reclutamento
        • Namokora HCIV
        • Contatto:
      • Omoro, Acholi, Uganda
        • Non ancora reclutamento
        • Lalogi HCIV
        • Contatto:
    • Bunyoro
      • Kikube, Bunyoro, Uganda
        • Non ancora reclutamento
        • Rwenyawawa HCIII
        • Contatto:
    • Busoga
      • Kaliro, Busoga, Uganda
        • Non ancora reclutamento
        • Nawaikoke HCIII
        • Contatto:
      • Mayuge, Busoga, Uganda
        • Non ancora reclutamento
        • Kigandalo HCIV
        • Contatto:
    • Karamoja
      • Moroto, Karamoja, Uganda
        • Non ancora reclutamento
        • Nadunget HCIII
        • Contatto:
    • Lango
      • Otuke, Lango, Uganda
        • Non ancora reclutamento
        • Orum HCIV
        • Contatto:
      • Oyam, Lango, Uganda
        • Non ancora reclutamento
        • Otwal HCIII
        • Contatto:

Criteri di partecipazione

I ricercatori cercano persone che corrispondano a una certa descrizione, chiamata criteri di ammissibilità. Alcuni esempi di questi criteri sono le condizioni generali di salute di una persona o trattamenti precedenti.

Criteri di ammissibilità

Età idonea allo studio

  • Bambino

Accetta volontari sani

No

Metodo di campionamento

Campione non probabilistico

Popolazione di studio

Children younger than 5 years who reside in the catchment areas of selected health facilities in R21/Matrix-M implementation districts in Burkina Faso or Uganda, are age-eligible for vaccination under the relevant national schedule, and present for outpatient care with suspected malaria. Participants are recruited from health facilities in moderate- to high-transmission settings.

Descrizione

Inclusion Criteria:

  • Residence in an area where R21/Matrix-M is implemented and within the catchment area of a selected study facility.
  • Younger than 5 years and eligibleto receive R21/Matrix-M under the national vaccination schedule at rollout.
  • Meets the country definition of suspected malaria, generally axillary temperature of at least 37.5 degrees Celsius or a history of fever within the previous 24 hours, and is undergoing malaria testing.
  • Written informed consent provided by an adult caregiver aged 18 years or older.

Exclusion Criteria:

  • Caregiver is unable or unwilling to provide informed consent.
  • Severe non-malaria illness at presentation that would interfere with study participation.
  • Repeat presentation within the protocol-defined exclusion window after a previous enrollment: within 14 days after a microscopy-positive visit; or more than 7 but fewer than 14 days after a microscopy-negative visit. A microscopy-negative visit followed by a positive diagnosis within 7 days will be reclassified as positive rather than treated as a new enrollment.
  • Documented receipt of any RTS,S malaria vaccine dose.

Piano di studio

Questa sezione fornisce i dettagli del piano di studio, compreso il modo in cui lo studio è progettato e ciò che lo studio sta misurando.

Come è strutturato lo studio?

Dettagli di progettazione

Coorti e interventi

Gruppo / Coorte
Intervento / Trattamento
Suspected malaria cases that test positive using microscopy
Eligible children with suspected malaria whose enrollment blood smear microscopy result is positive for P. falciparum infection
Biologico: R21/Matris-M Malaria vaccine
R21/Matrix-M vaccination received through routine national immunization programs. The study will record the number and dates of doses received. Children will be classified as having received 0, 1, 2, 3, or 4 eligible doses, with prespecified grouped classifications used if individual dose categories are underpowered. Doses given fewer than 14 days before malaria testing will not count toward the primary exposure classification.
Suspected malaria cases that test negative using microscopy
Eligible children with suspected malaria whose enrollment blood smear microscopy result is negative for P. falciparum infection
Biologico: R21/Matris-M Malaria vaccine
R21/Matrix-M vaccination received through routine national immunization programs. The study will record the number and dates of doses received. Children will be classified as having received 0, 1, 2, 3, or 4 eligible doses, with prespecified grouped classifications used if individual dose categories are underpowered. Doses given fewer than 14 days before malaria testing will not count toward the primary exposure classification.

Cosa sta misurando lo studio?

Misure di risultato primarie

Misura del risultato
Misura Descrizione
Lasso di tempo
Dose-specific effectiveness of R21/Matrix-M against microscopy-confirmed clinical malaria
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month study recruitment period
Adjusted vaccine effectiveness will be calculated as (1 - adjusted odds ratio) x 100%. The odds ratio will compare the odds of each documented R21/Matrix-M dose category among microscopy-positive malaria cases with the odds among microscopy-negative controls, using children with 0 doses as the primary reference group. Prespecified grouped dose categories will be used if individual dose categories do not have adequate statistical power.
At the enrollment illness episode, during the approximately 7- to 8-month study recruitment period

Misure di risultato secondarie

Misura del risultato
Misura Descrizione
Lasso di tempo
Effectiveness of R21/Matrix-M by time since vaccination
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Adjusted vaccine effectiveness will be estimated by categorical and/or continuous time since the most recent eligible vaccine dose, including interactions between dose and time.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Effect modification of vaccine effectiveness by malaria transmission intensity
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Dose-specific vaccine effectiveness will be compared across prespecified malaria transmission levels within each country.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Effect modification of vaccine effectiveness by sex
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Dose-specific vaccine effectiveness will be estimated using vaccination-by-sex interaction terms and sex-stratified analyses.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Effect modification by other malaria prevention interventions
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Dose-specific vaccine effectiveness will be assessed in relation to seasonal malaria chemoprevention, insecticide-treated net use, and indoor residual spraying using interaction analyses.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Effectiveness according to vaccine dose timing
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Among vaccinated children, effectiveness will be compared for on-time and late vaccination and in analyses restricted to doses spaced 3 to 5 weeks apart. A late dose is defined as a dose received at least 2 weeks after the scheduled date.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Effectiveness of the fourth dose relative to the three-dose primary series
Lasso di tempo: At the enrollment illness episode, during the approximately 7- to 8-month recruitment period
Adjusted vaccine effectiveness of 4 doses compared with 3 doses will be estimated using the odds of microscopy-confirmed malaria.
At the enrollment illness episode, during the approximately 7- to 8-month recruitment period

Collaboratori e investigatori

Qui è dove troverai le persone e le organizzazioni coinvolte in questo studio.

Sponsor

Clinton Health Access Initiative Inc.

Collaboratori

University of California, San Francisco
Institut de Recherche en Sciences de la Sante, Burkina Faso
Ministry of Health, Uganda
Ministry of Health, Burkina Faso
Infectious Diseases Research Collaboration, Uganda

Investigatori

  • Investigatore principale: Isabel Rodriguez-Barraquer, MD, PhD, University of California, San Francisco
  • Investigatore principale: Halidou Tinto, PhD, Institut de Recherche en Sciences de la Santé (Burkina Faso)
  • Investigatore principale: Joaniter Nankabirwa, MD, PhD, Infectious Diseases Research Collaboration, Kampala, Uganda

Studiare le date dei record

Queste date tengono traccia dell'avanzamento della registrazione dello studio e dell'invio dei risultati di sintesi a ClinicalTrials.gov. I record degli studi e i risultati riportati vengono esaminati dalla National Library of Medicine (NLM) per assicurarsi che soddisfino specifici standard di controllo della qualità prima di essere pubblicati sul sito Web pubblico.

Studia le date principali

Inizio studio (Effettivo)

14 luglio 2026

Completamento primario (Stimato)

1 giugno 2027

Completamento dello studio (Stimato)

1 agosto 2027

Date di iscrizione allo studio

Primo inviato

3 agosto 2026

Primo inviato che soddisfa i criteri di controllo qualità

3 agosto 2026

Primo Inserito (Effettivo)

6 agosto 2026

Aggiornamenti dei record di studio

Ultimo aggiornamento pubblicato (Effettivo)

6 agosto 2026

Ultimo aggiornamento inviato che soddisfa i criteri QC

3 agosto 2026

Ultimo verificato

1 agosto 2026

Maggiori informazioni

Termini relativi a questo studio

Parole chiave

Termini MeSH pertinenti aggiuntivi

Altri numeri di identificazione dello studio

  • AVERT-2026-01
  • INV-097482 (Altro numero di sovvenzione/finanziamento: Gates Foundation)
  • 2026-06-05 (Altro numero di sovvenzione/finanziamento: Givewell)

Piano per i dati dei singoli partecipanti (IPD)

Hai intenzione di condividere i dati dei singoli partecipanti (IPD)?

INDECISO

Informazioni su farmaci e dispositivi, documenti di studio

Studia un prodotto farmaceutico regolamentato dalla FDA degli Stati Uniti

No

Studia un dispositivo regolamentato dalla FDA degli Stati Uniti

No

Queste informazioni sono state recuperate direttamente dal sito web clinicaltrials.gov senza alcuna modifica. In caso di richieste di modifica, rimozione o aggiornamento dei dettagli dello studio, contattare register@clinicaltrials.gov. Non appena verrà implementata una modifica su clinicaltrials.gov, questa verrà aggiornata automaticamente anche sul nostro sito web .

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