Strategies for Increasing RSV Vaccination During Pregnancy

(PRIME Trial)

Overseen By Jeannie C Kelly

Age: 18+

Sex: Female

Trial Phase: Phase 3

Sponsor: Washington University School of Medicine

Disqualifiers: No confirmed IUP, Severe allergy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 2

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests various methods to encourage pregnant individuals to receive the RSV vaccine, which protects against respiratory infections. Researchers aim to determine if additional support, such as MyChart nurse messages, informative videos from the Society for Maternal-Fetal Medicine (SMFM), or visual aids, proves more effective than standard doctor recommendations. Participants will be divided into groups receiving different combinations of these supports to identify the most effective approach. The trial seeks individuals who are 28-30 weeks pregnant, with no history of severe allergic reactions to vaccines or active illnesses. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants the opportunity to contribute to research that could soon benefit many.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It mainly focuses on your pregnancy status and any allergies to the RSV vaccine.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that RSV vaccines are safe for pregnant women. Studies have found no increased risk of early birth or other complications for those who receive the vaccine. Real-world evidence indicates that birth outcomes are similar for both vaccinated and unvaccinated women. However, some reports mention a possible increase in high blood pressure issues in pregnant women who received the vaccine. Despite this, experts generally recommend RSV vaccination during pregnancy to protect both the mother and baby from the virus. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores innovative ways to boost RSV vaccination rates during pregnancy. Unlike standard methods that rely heavily on routine counseling, this trial tests the effectiveness of using MyChart nurse messages, educational videos from the Society for Maternal-Fetal Medicine (SMFM), and visual aids. These tools aim to provide timely, personalized reminders and engaging educational content, potentially making it easier for expectant mothers to understand the benefits of RSV vaccination and take action. By studying these strategies, researchers hope to identify more effective approaches to increase vaccination uptake and ultimately improve maternal and infant health outcomes.

What evidence suggests that this trial's treatments could be effective for increasing RSV vaccination during pregnancy?

Research has shown that receiving the RSV vaccine during pregnancy can significantly reduce the risk of severe RSV (respiratory syncytial virus) illness in newborns. Specifically, studies have found that the vaccine can lower the likelihood of a baby needing hospital care for RSV by 57%. In this trial, participants will be randomized into different groups to test various strategies for increasing vaccination rates. Some participants will receive routine counseling, while others will also receive visual aids, videos, or messages from nurses to encourage vaccination. These methods aim to increase vaccine use and protect babies from RSV. ^{2 3 6 7 8}

Are You a Good Fit for This Trial?

This trial is for pregnant individuals between 28-36 weeks gestation. It's designed to test if multiple strategies can increase RSV vaccination rates during pregnancy compared to standard care.

Inclusion Criteria

No contraindications to the RSV vaccine: history of severe allergic reaction to any vaccine component or active moderate/severe acute illness with or without fever or receipt of RSV vaccine during the pregnancy

I am confirmed to be 28-30 weeks pregnant.

Exclusion Criteria

Those who do not have confirmed IUP at 28-30 weeks

Those with a contraindication to the RSV vaccine: history of severe allergic reaction to any vaccine component or active moderate/severe acute illness with or without fever or receipt of RSV vaccine during the pregnancy

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Early Intervention

Participants receive low-intensity interventions such as physician counseling and visual aids at 28-30 weeks gestation to increase RSV vaccination uptake.

2 weeks

1 visit (in-person)

Late Intervention

Participants who remain unvaccinated at 34 weeks receive higher-intensity interventions such as targeted phone calls or physician reminders to increase RSV vaccination uptake.

2 weeks

1 visit (in-person)

Follow-up

Participants are monitored for vaccination status and safety until delivery.

6 weeks

What Are the Treatments Tested in This Trial?

Interventions

• MyChart nurse message
• SMFM video
• Visual aid

Trial Overview The study tests a bundle of strategies including MyChart nurse messages, an SMFM video, and visual aids at two different stages of pregnancy (early: 28-30 weeks, late: 34-36 weeks) to see which increases RSV vaccine uptake.

How Is the Trial Designed?

Group I: Routine counseling Active Control 1 Intervention

Randomized to routine counseling at 28-30 weeks

Group II: Routine counseling + MyChart nurse managing Active Control 1 Intervention

Randomized to routine counseling at 28-30 weeks; not vaccinated by 34 weeks, and randomized to receive a MyChart message from the nurse encouraging vaccination at 34 weeks

Group III: Routine counseling + SMFM video Active Control 1 Intervention

Randomized to routine counseling at 28-30 weeks; not vaccinated by 34 weeks, and randomized to watch the SMFM video on RSV vaccination at a prenatal visit at 34 weeks

Group IV: Routine counseling/visual aid + SMFM video Active Control 2 Interventions

Randomized to routine counseling and receipt of a visual aid encouraging RSV vaccination at 28-30 weeks; not vaccinated by 34 weeks, and randomized to watch the SMFM video on RSV vaccination at a prenatal visit at 34 weeks

Group V: Routine counseling/visual aid Active Control 1 Intervention

Randomized to routine counseling and receipt of a visual aid encouraging RSV vaccination at 28-30 weeks

Group VI: Routine counseling/visual aid + MyChart nurse message Active Control 2 Interventions

Randomized to routine counseling and receipt of a visual aid encouraging RSV vaccination at 28-30 weeks; not vaccinated by 34 weeks, and randomized to receive a MyChart message from the nurse encouraging vaccination at 34 weeks

Who Is Running the Clinical Trial?

Washington University School of Medicine

Lead Sponsor

Trials

2,027

Recruited

2,353,000+

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12404496/

Nurses' attitudes about RSV vaccination for pregnant ... We received 1,908 responses; 44% of participants agreed that pregnant women should receive an RSV vaccination, and 72% agreed that infants ...

2. cdc.gov cdc.gov/rsv/hcp/vaccine-clinical-guidance/pregnant-people.html

RSV Vaccine Guidance for Pregnant Women In the same trial, the RSV vaccine reduced the risk of the baby being hospitalized for RSV by 57% and risk of having a healthcare visit for RSV ...

3. withpower.com withpower.com/trial/phase-3-pregnant-state-9-2024-54876

Strategies for Increasing RSV Vaccination During Pregnancy Trial Overview The study tests a bundle of strategies including MyChart nurse messages, an SMFM video, and visual aids at two different stages of pregnancy ( ...

4. amga.org amga.org/getmedia/2a66980a-4d4a-49f0-ae42-1cb6b57b0ec3/AMGA_QuIC_MSRV_Phase-3_v4_links.pdf

Maternal RSV Vaccine Preparedness A study of Centers for Disease Control and Prevention (CDC) data revealed vaccine coverage among pregnant patients to be less than half for ...

5. safeinpregnancy.org safeinpregnancy.org/files/PROSPERO_RSVpreF%20.pdf

Effectiveness and immunogenicity of respiratory syncytial ... What is the efficacy/effectiveness of maternal RSVpreF vaccination during pregnancy in preventing RSV-specific and all-cause respiratory illness ...

6. cdc.gov cdc.gov/vaccine-safety/vaccines/rsv.html

Respiratory Syncytial Virus (RSV) Vaccine Safety GSK (Arexvy) and Moderna (mResvia) RSV vaccines are not recommended for pregnant women.

7. midwife.org midwife.org/american-college-of-nurse-midwives-statement-on-maternal-immunization-updated-july-2025/

Updated July 2025 Clinical trials demonstrate that RSV vaccination during pregnancy is safe, with no increased risk of preterm birth or other complications.

8. gavi.org gavi.org/vaccineswork/real-world-results-confirm-safety-rsv-vaccine-pregnancy

Real-world results confirm safety of RSV vaccine in ... Study suggests similar risk of preterm birth in women who were vaccinated against respiratory syncytial virus (RSV) during pregnancy and those who were not.