Pregnancy shot may shield newborns from deadly RSV – major brazil trial launches
NCT ID NCT07445763
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study will check how well a new RSV vaccine (RSVpreF) works when given to pregnant women in Brazil. Researchers will follow 5,000 infants up to 6 months old who are hospitalized or seen in clinics for respiratory illness. By comparing babies whose mothers got the vaccine to those who didn't, they hope to measure real-world protection against severe RSV disease.
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Study facts
What this study's own registry entry says, in plain language.
- Participants
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About 5,000 people
The number the study aims to enrol. It can still change while the study runs.
- Expected to start
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Apr 2026
An estimate. Start dates often move.
- Expected to finish
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Dec 2028
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
Who is studied
Infants with acute respiratory illness (ARI)
- Ages
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0 to 360 days
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
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.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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