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Fluad vs. Fluzone High-Dose Vaccine Effectiveness in Adults 65+

This study is comparing two different flu vaccines, Fluad Quadrivalent and Fluzone High-Dose Quadrivalent, to see which is more effective in preventing the flu and related health problems in adults aged 65 and older. Researchers will look at how well these vaccines prevent PCR-confirmed influenza (flu confirmed by a lab test). You can join if you are 65 or older, are a Kaiser Permanente Northern California (KPNC) member, and receive either of these flu vaccines at a KPNC facility during the 2023/24 or 2024/25 flu seasons. The study is currently unclear on its recruitment status, but it plans to include a large number of participants, around 960,000.

Study design
This is an observational study, meaning researchers will watch and collect information from a large group of people (around 960,000) who receive one of the two flu vaccines.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed from at least 14 days after vaccination until the end of each flu season (estimated May 2024 or May 2025), or until an outcome occurs, death, or loss-to-follow-up.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06029933

Fluad vs. Fluzone High-Dose Vaccine Effectiveness Among Adults ≥65 Years

Recruiting
Not specifiedAges 65+Observational
Kaiser Permanente
~1,500,000 participants
Updated 2026-08-05 on ClinicalTrials.gov
What's tested:Adjuvanted Quadrivalent Inactivated Influenza Vaccine (aIIV4)High-Dose Quadrivalent Inactivated Influenza Vaccine (HD-IIV4)

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
PCR-confirmed influenza
Measured over ≥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)

Conditions

Influenza
Community-acquired Pneumonia
Cardiovascular Events

Explore related trials

Influenza

Where it's being run

1 sites across 1 states
California1

Who to contact

Amber H. Hyman, PhD, MPH
[email protected]
510-267-7571
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

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

Exclusion

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

What this trial measures

  • PCR-confirmed influenza≥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)

    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.