Fluad vs. Fluzone High-Dose Vaccine Effectiveness Among Adults ≥65 Years
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age65+
SponsorKaiser Permanente
About this trial
This study will evaluate the relative vaccine effectiveness of quadrivalent adjuvanted inactivated influenza vaccine (aIIV4) versus quadrivalent high-dose inactivated influenza vaccine (HD-IIV4) in preventing polymerase chain reaction (PCR)-confirmed influenza and influenza-related outcomes in adults ≥65 years of age during the 2023/24, 2024/25, and 2026/27 influenza seasons. The study is an observational study conducted at Kaiser Permanente Northern California (KPNC), an integrated health care system in the United States.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Age ≥65 years at the time of influenza vaccination
KPNC member at the time of vaccination
Receive either aIIV4 or HD-IIV4 at a KPNC facility during the 2023/24 and/or 2024/25 influenza seasons
Disqualifiers
Age <65 years at the time of influenza vaccination
Received either aIIV4 or HD-IIV4 in the inpatient setting
Receive more than one influenza vaccination during a single season period (i.e., 2023/24 or 2024/25 influenza seasons)
Receive an influenza vaccination outside of KPNC
Trial population
This study includes KPNC adults ≥65 years who receive Fluad or Fluzone High-Dose influenza vaccine as part of routine clinical care during the 2023/24, 2024/25, and/or 2026/27 influenza seasons.
Trial design
Design model
Cohort
Time perspective
Retrospective
Treatments tested in this trial
Adjuvanted Quadrivalent Inactivated Influenza Vaccine (aIIV4)
Biological/VaccineFluad Quadrivalent vaccine is an inactivated influenza vaccine formulated to contain 60 mcg of hemagglutinin (HA) total, with 15 mcg from each of the four recommended influenza strains and the MF59 adjuvant in single-dose prefilled 0.5 mL syringes. Kaiser Permanente Northern California members ≥65 years may receive Fluad as part of routine clinical care during the influenza season.
High-Dose Quadrivalent Inactivated Influenza Vaccine (HD-IIV4)
Biological/VaccineFluzone High-Dose Quadrivalent vaccine is an inactivated split virion influenza vaccine formulated to contain 240 mcg of HA total, with 60 mcg from each of the four recommended influenza strains in single-dose prefilled 0.7 mL syringes. Kaiser Permanente Northern California members ≥65 years may receive Fluzone High-Dose as part of routine clinical care during the influenza season.
Treatment groups
1,500,000 Participants
are divided into 2 treatment groupsGroup A: Fluad Recipients1 intervention
Group B: Fluzone High-Dose Recipients1 intervention
Trial outcomes
Primary outcomes
1
PCR-confirmed influenza
KPNC members ≥65 years who receive Fluad or Fluzone High-Dose will be retrospectively assessed for the presence of PCR-confirmed influenza. This outcome will be assessed in single-season analyses (2023/24, 2024/25, and 2026/27 separately) and a pooled analysis across all seasons.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)Secondary outcomes
1
Emergency department visit or hospitalization for PCR-confirmed influenza
KPNC members ≥65 years who receive Fluad or Fluzone High-Dose will be retrospectively assessed for an emergency department visit or hospitalization for PCR-confirmed influenza. This outcome will be assessed in single-season analyses (2023/24, 2024/25, and 2026/27 separately) and a pooled analysis across all seasons combined.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)2
Hospitalization for PCR-confirmed influenza
KPNC members ≥65 years who receive Fluad or Fluzone High-Dose will be retrospectively assessed for hospitalization for PCR-confirmed influenza. This outcome will be assessed in a pooled analysis across all seasons combined.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)3
Hospitalization for all-cause community-acquired pneumonia
KPNC members ≥65 years who receive Fluad or Fluzone High-Dose will be retrospectively assessed for hospitalization for all-cause community-acquired pneumonia. This outcome will be assessed in single-season analyses (2023/24, 2024/25, and 2026/27 separately) and a pooled analysis across all seasons combined.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)Other outcomes
1
Hospitalization for cardiovascular events
KPNC members ≥65 years who receive Fluad or Fluzone High-Dose will be retrospectively assessed for hospitalization for cardiovascular events. This outcome will be assessed in single-season analyses (2023/24, 2024/25, and 2026/27 separately) and a pooled analysis across all seasons combined.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)2
PCR-confirmed influenza in subgroups with comorbidities
KPNC members ≥65 years with comorbidities (e.g., cardiovascular and respiratory conditions, diabetes, obesity) who receive Fluad or Fluzone High-Dose will be retrospectively assessed for hospitalization for PCR-confirmed influenza. This outcome will be assessed in a pooled analysis across all seasons combined.
Time frame
≥14 days after vaccination until date of outcome, death, loss-to-follow-up, or end of each season (estimated May 2024, May 2025, or May 2027)Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Kaiser Permanente
Lead sponsor
Seqirus
Collaborator
Source ClinicalTrials.gov