Maternal RSV Vaccine Before Birth and Infant RSV-Related Illness in Brazil

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

Tarsila is an observational, test-negative, case-control study conducted in southern Brazil to measure real-world effectiveness of maternal RSVpreF vaccination. Two parallel components enroll infants with acute respiratory illness: hospitalized cases and outpatient cases, using RT-qPCR to classify RSV status. Mothers' vaccination status and potential confounders are collected from interviews and medical records to estimate vaccine effectiveness against RSV-associated ARI in infancy, aligned with the national vaccination rollout from December 2025 through September 2028. Enrollment spans April 2026 to September 2028 across multiple centers in Paraná and neighboring states. The design parallels other real-world effectiveness studies and relies on a standardized case definition for consistent comparisons.

Why it matters

Who can join: the full rules

Tarsila Inpatient Study

Inclusion Criteria

* Infant born in Brazil.
* Mother resident in Brazil during the related pregnancy.
* Infant date of birth 14 days or more after start of the first national RSVpreF vaccination campaign to ensure potential to have been born to an RSVpreF-vaccinated mother.
* Infant ≤360 days of age at time of RSV specimen collection.
* Infant born at ≥37 weeks of gestational age.
* Infant hospital admission for at least 24 hours with signs and symptoms meeting the case definition of ARI, defined as the presence of any of the following: nasal secretion for ≥24 hours; respiratory distress, labored breathing, or tachypnea (respiratory rate ≥60 breaths/min for infants \<2 months or ≥50 breaths/min for infants 2-12 months); cough; inability to feed for any period due to respiratory symptoms; apnea; or other relevant respiratory symptoms (examples include but are not limited to wheezing, crackles, and nasal flaring).

Exclusion Criteria:

* Maternal or infant receipt of any other licensed or investigational RSV preventive product.
* Infant receipt of blood transfusion or other blood products containing antibodies since birth.
* Infant previously enrolled in this study.
* Lack of informed consent from the mother or the infant's legal guardian.
* Absent or inconclusive RT-qPCR result for RSV.
* Birth to a mother whose RSVpreF vaccination status could not be confirmed.

Tarsila Outpatient Study

Inclusion Criteria:

* Infant born in Brazil.
* Mother resident in Brazil during the related pregnancy.
* Infant date of birth 14 days or more after start of the first national RSVpreF vaccination campaign to ensure potential to have been born to an RSVpreF-vaccinated mother.
* Infant ≤360 days of age at time of RSV specimen collection.
* Infant born at ≥37 weeks of gestational age.
* Infant presentation to an outpatient healthcare facility with signs and symptoms meeting the case definition of ARI, defined as the presence of any of the following: nasal secretion for ≥24 hours; respiratory distress, labored breathing, or tachypnea (respiratory rate ≥60 breaths/min for infants \<2 months or ≥50 breaths/min for infants 2-12 months); cough; inability to feed for any period due to respiratory symptoms; apnea; or other relevant respiratory symptoms (examples include but are not limited to wheezing, crackles, and nasal flaring).

Exclusion Criteria:

* Mother or infant receipt of any other licensed or investigational RSV preventive product.
* Infant receipt of blood transfusion or other blood products containing antibodies since birth.
* Lack of informed consent from the mother or the infant's legal guardian.
* Absent or inconclusive RT-qPCR result for RSV.
* Birth to a mother whose RSVpreF vaccination status could not be confirmed.
* Enrollment in the study within the previous 30 days. If the interval exceeds 30 days, infants will be excluded if any previous episode tested positive for RSV.

Where it's running

• Unidade de Pronto Atendimento Veneza
  Cascavel, Paraná, Brazil Recruiting
• Complexo do Hospital de Clínicas da Universidade Federal do Paraná
  Curitiba, Paraná, Brazil Recruiting
• Hospital Infantil Pequeno Príncipe
  Curitiba, Paraná, Brazil Recruiting
• Unidade de Pronto Atendimento 24 Horas Dr. Edgar Netzel
  Marechal Cândido Rondon, Paraná, Brazil Recruiting
• Unidade de Saúde Central de Palotina
  Palotina, Paraná, Brazil Recruiting
• Unidade de Pronto Atendimento II de Toledo
  Toledo, Paraná, Brazil Recruiting

Study contacts

• Principal investigator: Maicon Falavigna — Inova Medical
• Study coordinator: Maicon Falavigna, MD PhD
• Email: research@inovamedical.com.br
• Phone: +55 51 2399 1750

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.