Immunogenicity of RSV Vaccines in Residents of Long-Term Care Facilities (LTCF)

This was an open label non-inferiority study to evaluate immunogenicity where all participants received either the Pfizer RSV Vaccine (ABRYSVO) or GSK RSV Vaccine (AREXVY) as part of Standard of Care (SOC). Hereafter, vaccines will be referred to as Pfizer and GSK.

The study was conducted at the University of Rochester Medical Center (URMC) Infectious Disease Research Clinic (IDRC) and 2 local LTCFs. Vaccinations were carried out between November and December 2023. LTCF A provided GSK vaccine and LTCF B provided Pfizer vaccine to their residents as part of SOC. The community cohort was divided equally to receive Pfizer and GSK to mirror the Pfizer and GSK vaccinations in LTCF. The study was reviewed and approved by the University of Rochester Institutional Review Board and leadership at the local LTCFs. Participants or their legally authorized representative (LAR) signed written informed consent. Verbal consent by LAR was also accepted given the minimal risk nature of the study.

Participants:

Inclusion criteria

were intended to be broad with relatively few exclusions to reflect a real-life population in LTCF and the older adults in the community. Inclusion criteria included: ≥60 years of age living LTCF or residing independently in the community, planning to receive a SOC RSV vaccine, life expectancy of >6 months, able to sign informed consent or to provide consent via a LAR. Exclusions included: history of a current immunosuppressive condition or medications, history of hypersensitivity or reaction to any vaccine component, any routine vaccination within a 14-day window before or planned after RSV vaccination, previous receipt or intended receipt of an RSV vaccine outside the study, receipt of blood/plasma products or immunoglobulin within 60 days before RSV vaccination, and documented RSV infection within 2 months prior to enrollment.

Study Procedures:

Prior to any study procedures informed consent was obtained from the participant or LAR. At enrollment demographic and medical history data were collected. A clinical assessment including vital signs and a symptom directed targeted physical exam was performed. Ten 10cc of blood was collected. Vaccination in LTCF were performed by the staff at each facility per SOC and the vaccine product and date of vaccination recorded. Vaccination of the community cohort was performed in the IDRC at enrollment visit. Visit two was scheduled 28 to 42 days following vaccination at which time a second 10cc blood sample was collected and participants were queried about any intercurrent illnesses. Results of any viral testing performed as part of standard of care were recorded. If a participant had an intercurrent RSV infection prior to RSV vaccination and vaccination was deferred, visit 2 was scheduled 28 -42 days after infection was documented.

Inclusion criteria

• ≥60 years of age who live in skilled nursing facilities or reside independently in the community
• Life expectancy of >6 months, as assessed by the investigator
• Able to sign informed consent or to provide consent via a legally authorized representative (LAR)

Exclusion criteria

• History of a current immunosuppressive condition or receipt of chemotherapy or other immunosuppressive or cytotoxic therapy, including chronic prednisone use of ≥ 20 mg/day for more than 14 days within 3 months of study vaccination
• History of hypersensitivity or reaction to any vaccine component
• Simultaneous administration of another vaccine (influenza, SARS-CoV-2) or within a 14-day window before or after intervention
• Previous receipt or intended receipt of an RSV vaccine outside the study
• Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration.
• Documented RSV infection within 2 months prior to study intervention.