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

3 de agosto de 2026 atualizado por: 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.

Visão geral do estudo

Status

Recrutamento

Condições

Intervenção / Tratamento

Descrição detalhada

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 de estudo

Observacional

Inscrição (Estimado)

20000

Contactos e Locais

Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.

Locais de estudo

  • Burkina Faso
    • Boucle Mouhoun
      • Boromo, Boucle Mouhoun, Burkina Faso
        • Recrutamento
        • Boromo urbain 1
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Boromo, Boucle Mouhoun, Burkina Faso
        • Recrutamento
        • Ouahabou
        • Contato:
          • h Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
    • Hauts-Bassins Region
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Béréba
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Dohoun
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Houndé, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Kari
        • Contato:
          • Halidou Tinto
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Déguélin
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Karangasso-Vigué
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Sourmousso
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Karangasso-Vigué, Hauts-Bassins Region, Burkina Faso
        • Recrutamento
        • Wara
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
    • Oubri
      • Zorgo, Oubri, Burkina Faso
        • Recrutamento
        • Mankarga T
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Zorgo, Oubri, Burkina Faso
        • Recrutamento
        • Mankarga V3
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
      • Zorgo, Oubri, Burkina Faso
        • Recrutamento
        • Mankarga V6
        • Contato:
          • Halidou Tinto, PhD
          • Número de telefone: +226 25 40 92 12
          • E-mail: tintoh@crun.bf
  • Uganda
    • Acholi
      • Kitgum, Acholi, Uganda
        • Ainda não está recrutando
        • Kitgum-Matidi HCIII
        • Contato:
      • Kitgum, Acholi, Uganda
        • Ainda não está recrutando
        • Namokora HCIV
        • Contato:
      • Omoro, Acholi, Uganda
        • Ainda não está recrutando
        • Lalogi HCIV
        • Contato:
    • Bunyoro
      • Kikube, Bunyoro, Uganda
        • Ainda não está recrutando
        • Rwenyawawa HCIII
        • Contato:
    • Busoga
      • Kaliro, Busoga, Uganda
        • Ainda não está recrutando
        • Nawaikoke HCIII
        • Contato:
      • Mayuge, Busoga, Uganda
        • Ainda não está recrutando
        • Kigandalo HCIV
        • Contato:
    • Karamoja
      • Moroto, Karamoja, Uganda
        • Ainda não está recrutando
        • Nadunget HCIII
        • Contato:
    • Lango
      • Otuke, Lango, Uganda
        • Ainda não está recrutando
        • Orum HCIV
        • Contato:
      • Oyam, Lango, Uganda
        • Ainda não está recrutando
        • Otwal HCIII
        • Contato:

Critérios de participação

Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.

Critérios de elegibilidade

Idades elegíveis para estudo

  • Filho

Aceita Voluntários Saudáveis

Não

Método de amostragem

Amostra Não Probabilística

População do estudo

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.

Descrição

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.

Plano de estudo

Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.

Como o estudo é projetado?

Detalhes do projeto

Coortes e Intervenções

Grupo / Coorte
Intervenção / Tratamento
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
Biológico: 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
Biológico: 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.

O que o estudo está medindo?

Medidas de resultados primários

Medida de resultado
Descrição da medida
Prazo
Dose-specific effectiveness of R21/Matrix-M against microscopy-confirmed clinical malaria
Prazo: 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

Medidas de resultados secundários

Medida de resultado
Descrição da medida
Prazo
Effectiveness of R21/Matrix-M by time since vaccination
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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

Colaboradores e Investigadores

É aqui que você encontrará pessoas e organizações envolvidas com este estudo.

Patrocinador

Clinton Health Access Initiative Inc.

Colaboradores

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

Investigadores

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

Datas de registro do estudo

Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados ​​pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.

Datas Principais do Estudo

Início do estudo (Real)

14 de julho de 2026

Conclusão Primária (Estimado)

1 de junho de 2027

Conclusão do estudo (Estimado)

1 de agosto de 2027

Datas de inscrição no estudo

Enviado pela primeira vez

3 de agosto de 2026

Enviado pela primeira vez que atendeu aos critérios de CQ

3 de agosto de 2026

Primeira postagem (Real)

6 de agosto de 2026

Atualizações de registro de estudo

Última Atualização Postada (Real)

6 de agosto de 2026

Última atualização enviada que atendeu aos critérios de controle de qualidade

3 de agosto de 2026

Última verificação

1 de agosto de 2026

Mais Informações

Termos relacionados a este estudo

Palavras-chave

Termos MeSH relevantes adicionais

Outros números de identificação do estudo

  • AVERT-2026-01
  • INV-097482 (Número de outro subsídio/financiamento: Gates Foundation)
  • 2026-06-05 (Número de outro subsídio/financiamento: Givewell)

Plano para dados de participantes individuais (IPD)

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INDECISO

Informações sobre medicamentos e dispositivos, documentos de estudo

Estuda um medicamento regulamentado pela FDA dos EUA

Não

Estuda um produto de dispositivo regulamentado pela FDA dos EUA

Não

Essas informações foram obtidas diretamente do site clinicaltrials.gov sem nenhuma alteração. Se você tiver alguma solicitação para alterar, remover ou atualizar os detalhes do seu estudo, entre em contato com register@clinicaltrials.gov. Assim que uma alteração for implementada em clinicaltrials.gov, ela também será atualizada automaticamente em nosso site .

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