Arexvy RSV vaccine immune response in older adults

Immunogenicity After a Prime Dose and Revaccination With Adjuvanted RSVPreF3 Vaccine in the Most Elderly and Frail Population - an Open-labeled Phase IIIb-trial

This will test whether the Arexvy RSV vaccine produces different immune responses in adults aged 80 and older compared with adults aged 60–65.

Quick facts

• Phase: PHASE3
• Study type: Interventional
• Enrollment: 65 (estimated)
• Ages: 60 Years and up
• Sex: All
• Sponsor: Karolinska Institutet (other)
• Locations: 2 sites (Saltsjöbaden and 1 other locations)
• Trial ID: NCT07203365 on ClinicalTrials.gov

What this trial studies

This Phase 3 interventional study compares immune responses after a single Arexvy vaccination between two age groups: adults aged 80 years and older and a comparator group aged 60–65 years. Participants who are medically stable and can give written consent will receive Arexvy and have blood drawn to measure antibody and neutralizing responses, particularly against the prefusion F protein. The study enrolls community-dwelling and long-term care residents in the Stockholm area and follows participants for immunogenicity endpoints. Results will show whether age-related differences exist in the magnitude or quality of vaccine-induced antibodies.

Who should consider this trial

Good fit: Ideal candidates are medically stable adults aged 80 years or older and comparator adults aged 60–65 who live in the community or long-term care, can read Swedish, and can give written consent.

Not a fit: People who are immunocompromised, recently had hematopoietic stem cell transplant or active graft-versus-host disease, or cannot provide consent are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the results could help tailor RSV vaccination strategies and improve protection recommendations for people aged 80 and older.

How similar studies have performed: Approved RSV vaccines including Arexvy have demonstrated efficacy in adults 60+, but direct immunogenicity comparisons focused specifically on adults aged 80+ are limited, making this comparison relatively novel.

Eligibility criteria

Inclusion Criteria:

* Male or female individuals who were born between 1965 and 1960 or 1945 and before, at the time of the first vaccination, who live in the community or in a long-term care facility.
* Individuals who can understand and read Swedish.
* Individuals who can provide written consent and agree (by written consent) to receive the Arexvy vaccine.
* Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol.
* Participants who are medically stable in the opinion of the investigator at the time of first vaccination.
* Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease, are allowed to participate if considered by the investigator as medically stable.

Exclusion Criteria:

* Individuals who are medically immunocompromised, less than 2 years since hematopoietic stem cell transplantation (HSCT) or graft-versus-host disease (GVHD), solid-organ transplanted, using immunosuppressive drugs for treatment of cancer and who have inflammatory mediated or autoimmune conditions, as judged by the Investigator.
* Individuals who have already received an RSV vaccine dose at any time in the past.
* Any known or suspected reaction, hypersensitivity or allergies to be exacerbated by any product or component included in the vaccine and trial.
* Mental inability, reluctance or language difficulties that result in difficulty understanding the meaning of participation in the trial.
* Treatment or disease which, according to the investigator, can affect treatment or trial results.
* Any of the following medical conditions: Unstable chronic illness, Recurrent or un-controlled neurological disorders or seizures, Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study, Any other medical condition that in the judgment of the investigator would make intramuscular injection unsafe, Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study, Any history of dementia or any medical condition that moderately or severely impairs cognition and understanding of the informed consent form and/or study procedures, History of chronic alcohol consumption and/or drug abuse as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures.
* Participation in another clinical trial during the study period, or any previous clinical trials with RSV- or hMPV-vaccine or other prophylaxis.
* Planned move during the study period that will prohibit participating in the study until study end.
* Participation of any study personnel or their immediate dependents, family or household members as well as any family relations to Sponsor or PI.
* Co-administration of other vaccines less than 14 days before or after study vaccination. A period of less than 30 days before or after study vaccination applies in the case of Shingrix.

Where this trial is running

Saltsjöbaden and 1 other locations

• Familjeläkarna SÄBO — Saltsjöbaden, Sweden (RECRUITING)
• Akademiskt specialistcentrum Studieenheten — Stockholm, Sweden (RECRUITING)

Study contacts

• Principal investigator: Helena Hervius Askling, Dr — Studieenheten Akademiskt Specialistcentrum
• Study coordinator: Karin Loré, Professor

Conditions: RSV Immunisation, RISE, RSV vaccination, Respiratory syncytial virus, Elderly, Arexvy