RSV Vaccine for Transplant Recipients

(RSVax Trial)

Overseen By Victoria Hall, MBBS

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: University Health Network, Toronto

Must not be taking: IVIg, Rituximab

Disqualifiers: Pregnancy, CMV, RSV, others

Stay on Your Current Meds You can continue your current medications while participating

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

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 4

100 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new RSV vaccine to evaluate its safety and effectiveness in adults who have undergone lung or stem cell transplants. Researchers aim to determine if the vaccine can help these individuals build immunity (the body's defense against germs) without causing harmful side effects. The study seeks transplant recipients who are stable and have been out of surgery for a few months. Participants must also be willing to undergo blood tests a few weeks after receiving the vaccine. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants a chance to contribute to a potentially groundbreaking treatment.

Do I need to stop my current medications for the RSV vaccine trial?

The trial information does not specify if you need to stop your current medications. However, certain conditions like recent IVIg treatment, rituximab use, or active infections may affect your eligibility.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research has shown that the RSV vaccine is generally well-tolerated. In studies involving individuals with transplants and weakened immune systems, the RSV vaccine proved safe and effective. Participants demonstrated strong immune responses and did not experience major side effects.

Another study focused on organ transplant recipients. Most did not encounter significant issues after receiving the RSV vaccine. Out of 85 participants, 81 completed safety surveys, with only a few reporting mild reactions.

The CDC recommends the RSV vaccine for older adults, indicating confidence in its safety. While individual experiences may vary, these findings provide a reliable expectation. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike traditional antiviral treatments or prophylactic measures for RSV, the RSV vaccine for transplant recipients is designed specifically to enhance the immune response in individuals with weakened immune systems. Researchers are excited about this vaccine because it has the potential to offer direct protection by stimulating the body to produce its own antibodies against RSV, which is crucial for those who are more susceptible to severe infections. Moreover, this vaccine could reduce the need for repeated doses of antivirals, offering a more sustainable and long-term solution for preventing RSV in transplant patients.

What evidence suggests that this RSV vaccine might be an effective treatment for transplant recipients?

Research has shown that the RSV vaccine effectively protects against RSV infections. One study found it to be about 75% effective in adults over 60. For transplant patients, the vaccine proved safe and effective, regardless of the transplant type. Another study found it was 82.6% effective in preventing lung infections in older adults. In this trial, all adult transplant participants will receive the RSV vaccine, indicating it as a promising method to prevent RSV in transplant recipients. ^{2 6 7 8 9}

Who Is on the Research Team?

Victoria G Hall, MBBS

Principal Investigator

UHN Toronto

Are You a Good Fit for This Trial?

This trial is for adult lung and allogeneic hematopoietic stem cell transplant recipients who are more than 6 months post-transplantation. They should be stable outpatients to qualify.

Inclusion Criteria

I am more than 6 months post lung or bone marrow transplant and my condition is stable.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Vaccination

Participants receive a single dose of adjuvanted RSV vaccine

1 day

1 visit (in-person)

Initial Follow-up

Blood work collected to assess humoral and cellular immunity at 4 weeks post-vaccination

4 weeks

1 visit (in-person)

Extended Follow-up

Participants are monitored for adverse events, RSV infection, and durability of immunity at 6 and 12 months post-vaccination

12 months

2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• RSV Vaccine

Trial Overview The trial is testing the safety and immune response to a non-live RSV vaccine given to transplant recipients. Blood tests will measure immunity before and after vaccination, tracking any adverse reactions or complications.

How Is the Trial Designed?

Group I: RSV vaccine group Experimental Treatment 1 Intervention

Single arm open label study of RSV vaccine to all adult transplant participants enrolling into the study.

RSV Vaccine is already approved in Canada, United States for the following indications:

Approved in Canada as Arexvy for:

• Prevention of RSV lower respiratory tract infection in adults 60 years and older

Approved in United States as Arexvy for:

• Prevention of RSV lower respiratory tract infection in adults 60 years and older

Approved in United States as Abrysvo for:

• Prevention of RSV lower respiratory tract infection in adults 60 years and older
• Prevention of severe RSV disease in newborns when administered to pregnant women

Approved in Canada as Abrysvo for:

• Prevention of RSV lower respiratory tract infection in adults 60 years and older
• Prevention of severe RSV disease in newborns when administered to pregnant women

Who Is Running the Clinical Trial?

University Health Network, Toronto

Lead Sponsor

Trials

1,555

Recruited

526,000+

The PSI Foundation, Ontario

Collaborator

Trials

2

Recruited

160+

University of British Columbia

Collaborator

Trials

1,506

Recruited

2,528,000+

Published Research Related to This Trial

The study involving 48 young adults and 1005 older adults demonstrated that the RSVPreF3 vaccine significantly boosted immune responses, particularly after the first dose, with higher levels of RSV-specific antibodies and T cells observed in participants receiving the AS01-adjuvanted formulation.

Safety assessments revealed that most side effects were mild to moderate and temporary, with no significant safety concerns identified, leading to the selection of the AS01E-adjuvanted vaccine for further clinical development.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and Immunogenicity of a Respiratory Syncytial Virus Prefusion F (RSVPreF3) Candidate Vaccine in Older Adults: Phase 1/2 Randomized Clinical Trial. Leroux-Roels, I., Davis, MG., Steenackers, K., et al.[2023]

The RSV001 trial is a phase 1 study involving 70 healthy adults (ages 18-75) to evaluate the safety and immunogenicity of two novel RSV vaccines, PanAd3-RSV and MVA-RSV, using various prime/boost combinations.

Initial safety assessments showed that participants will monitor for adverse events for one week post-vaccination, ensuring that the vaccines are safe for both younger and older adults, which is crucial given the high-risk nature of RSV infection.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and immunogenicity of novel respiratory syncytial virus (RSV) vaccines based on the RSV viral proteins F, N and M2-1 encoded by simian adenovirus (PanAd3-RSV) and MVA (MVA-RSV); protocol for an open-label, dose-escalation, single-centre, phase 1 clinical trial in healthy adults. Green, CA., Scarselli, E., Voysey, M., et al.[2019]

The RSVPreF3 OA vaccine demonstrated high efficacy against RSV-related lower respiratory tract disease (94.6%) and acute respiratory illness (81.0%) in older adults with coexisting cardiorespiratory or endocrine/metabolic conditions, indicating it is effective for those at higher risk.

Immunogenicity results showed that post-vaccination neutralizing antibody levels in participants with these conditions were comparable to those without, suggesting that the vaccine is safe and effective across different health statuses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Respiratory Syncytial Virus Prefusion F Protein Vaccine Is Efficacious in Older Adults With Underlying Medical Conditions. Feldman, RG., Antonelli-Incalzi, R., Steenackers, K., et al.[2023]

Vaccination with the RSV vaccines Arexvy and Abrysvo can significantly reduce the health burden of RSV-related illnesses in older adults, providing substantial health benefits.

The cost-effectiveness analysis suggests that these vaccines are economically viable if priced under $120 per dose for Arexvy and $111 for Abrysvo, with potential budget impacts of up to $6.10 billion in the first RSV season.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cost-Effectiveness of Prefusion F Protein-Based Vaccines Against Respiratory Syncytial Virus Disease for Older Adults in the United States. Moghadas, SM., Shoukat, A., Bawden, CE., et al.[2023]

Vaccination with Arexvy and Abrysvo can significantly reduce the health burden of respiratory syncytial virus (RSV) in older adults, leading to fewer hospitalizations and deaths, making it a valuable intervention for this age group.

The cost-effectiveness analysis suggests that these vaccines could be economically viable, with a maximum price-per-dose of $127 for Arexvy and $118 for Abrysvo, potentially rising to $235 and $245 respectively if benefits extend into a second RSV season.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cost-effectiveness of Prefusion F Protein-based Vaccines Against Respiratory Syncytial Virus Disease for Older Adults in the United States. Moghadas, SM., Shoukat, A., Bawden, CE., et al.[2023]

In a study involving 122 older adults, a third dose of the RSVPreF3-AS01E vaccine was found to be well tolerated, with mostly mild-to-moderate side effects and no serious adverse events reported, indicating a good safety profile.

The third dose significantly boosted RSV-specific neutralizing antibodies and T-cell responses, demonstrating its immunogenicity, although the antibody levels after the third dose were lower than those observed one month after the first dose.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and Immunogenicity of a Revaccination With a Respiratory Syncytial Virus Prefusion F Vaccine in Older Adults: A Phase 2b Study. Leroux-Roels, I., Van Ranst, M., Vandermeulen, C., et al.[2023]

Respiratory syncytial virus (RSV) poses a significant health risk not only to infants but also to older adults, prompting urgent vaccine development efforts, with 19 candidates currently in clinical trials.

Advancements in understanding the RSV surface fusion glycoprotein have led to innovative vaccine strategies, including particle-based, live-attenuated, subunit, and vector-based approaches, although past trial failures indicate the need for improved knowledge on immunological protection.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The respiratory syncytial virus vaccine landscape: lessons from the graveyard and promising candidates. Mazur, NI., Higgins, D., Nunes, MC., et al.[2023]

Citations

1. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2839380

Respiratory Syncytial Virus Vaccination in Allogeneic ... This cohort study evaluates immune response to respiratory syncytial virus (RSV) vaccination in allogeneic hematopoietic stem cell ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12065041/

Effectiveness and Safety of Respiratory Syncytial Virus ... In this case-control study of 787 822 patients tested for RSV, vaccine effectiveness was approximately 75% among adults aged 60 years or ...

3. healio.com healio.com/news/infectious-disease/20251031/rsv-mrna-vaccine-safe-effective-for-transplant-patients

RSV mRNA vaccine safe, effective for transplant patients Researchers assessed Moderna's RSV vaccine in solid organ transplant patients. The vaccine was safe and effective regardless of transplant type.

4. clinicaltrialsarena.com clinicaltrialsarena.com/analyst-comment/idweek-2025-mrna-1345-rsv-vaccine-transplant-recipients/

IDWeek 2025: mRNA-1345 RSV vaccine is safe and ... The use of mRNA-1345 in transplant recipients is safe and effective, and some patients may benefit from a second dose. These findings are useful ...

5. sciencedirect.com sciencedirect.com/science/article/pii/S1198743X2500463X

Safety and immunogenicity of adjuvanted respiratory ... In a pivotal clinical trial comparing RSVPreF3 versus placebo, a first-year vaccine efficacy of 82.6% in preventing LRTD in people aged ≥60 ...

6. cdc.gov cdc.gov/rsv/vaccines/adults.html

Vaccines for Adults | RSV CDC recommends an RSV vaccine for all adults ages 75 years and older and for adults ages 50–74 years who are at increased risk of severe RSV.

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/41016596/

Safety and immunogenicity of adjuvanted respiratory ... Conclusions: The adjuvanted RSVPreF3 vaccine was immunogenic and well-tolerated with modest seroconversion but robust CD4+ T-cell responses.

8. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2833776

Respiratory Syncytial Virus Vaccine for US Adults Aged 60 ... In this case-control study of 787 822 patients tested for RSV, vaccine effectiveness was approximately 75% among adults aged 60 years or older.

9. amjtransplant.org amjtransplant.org/article/S1600-6135(25)01818-0/fulltext

Long-Term Safety of Respiratory Syncytial Virus ... Results: Between August 2023-December 2024, 85 SOTRs reported RSV vaccination of whom 81 (95%) returned ≥1 safety survey and 68 (80%) returned reactogenicity ...