Flublok v. Standard Dose Vaccine Effectiveness Among Kaiser Permanente Northern California Adults 18-64 Years

Completed

• Conditions: Stroke; Acute Myocardial Infarction; Congestive Heart Failure; Influenza; Lower Respiratory Tract Infection; Pneumonia
• Interventions: Biological: Flublok Quadrivalent; Biological: Standard Dose Inactivated Influenza Vaccine (SD-IIV)

• Registration Number: NCT03694392
• Lead Sponsor: Kaiser Permanente

Brief Summary

The overall objective of this study is to describe the effectiveness of Flublok Quadrivalent vaccine compared to standard dose inactivated influenza vaccine (SD-IIV) in adults 18 through 64 years of age. During this study, Flublok Quadrivalent or SD-IIV will be administered according to the guidelines in the Prescribing Information materials and only to persons for whom it is indicated. The 2018-2019, 2019-2020, and 2020-2021 formulations of recombinant influenza vaccine (Flublok Quadrivalent vaccine) and SD-IIV will be evaluated for outcomes including all polymerase chain reaction (PCR)-confirmed influenza, PCR-confirmed hospitalized influenza, hospitalized community-acquired pneumonia and cardio-respiratory events.

Detailed Description

Not available

Study Timeline

• Study Start: 2018-09-16
• Study First Submitted: 2018-09-27
• Study First Submitted QC: 2018-10-01
• Study First Posted: 2018-10-03
• Primary Completion: 2021-04-09
• Study Completion: 2022-12-31
• Results First Submitted: 2024-03-25
• Status Verified: 2025-03
• Results First Submitted QC: 2025-03-20
• Last Update Submitted: 2025-03-20
• Results First Posted: 2025-04-08
• Last Update Posted: 2025-04-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 2776278

Inclusion Criteria

• Between the ages of ≥18 and <65 years at the time of influenza vaccination
• Receive either Flublok Quadrivalent vaccine or standard dose inactivated influenza vaccine at a Kaiser Permanente Northern California facility during the study period from August 2018 through April 2020

Exclusion Criteria

• Children <18 years old
• Adults ≥65 years old

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Flublok Recipients	Flublok Quadrivalent	Kaiser Permanente Northern California members aged 18-64 years who receive Flublok Quadrivalent vaccine.
SD-IIV Recipients	Standard Dose Inactivated Influenza Vaccine (SD-IIV)	Kaiser Permanente Northern California members aged 18-64 years who receive standard dose inactivated influenza vaccine (SD-IIV).

Primary Outcome Measures

Name	Time	Method
Number of Adults 50-64 Years Old With Polymerase-chain Reaction (PCR) Confirmed Influenza Tests	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had a PCR-confirmed positive influenza test (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).

Secondary Outcome Measures

Name	Time	Method
Number of Adults 50-64 Years Old Hospitalized With PCR-confirmed Influenza	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had an inpatient stay and had a PCR-confirmed positive influenza test (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).
Number of Adults 50-64 Years Old Hospitalized With Community-acquired Pneumonia	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had an inpatient stay for community-acquired pneumonia (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).
Number of Adults 50-64 Years Old Hospitalized With Cardio-respiratory Events	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had an inpatient stay for cardio-respiratory events (e.g., pneumonia, other lower respiratory infections, acute myocardial infarction, congestive heart failure, stroke) (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).
Number of Adults 50-64 Years Old With Polymerase-chain Reaction (PCR) Confirmed Influenza A Tests	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had a PCR-confirmed positive influenza A test (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).
Number of Adults 50-64 Years Old With Polymerase-chain Reaction (PCR) Confirmed Influenza B Tests	Up to 8 months	Patients who receive either Flublok or SD-IIV will be retroactively assessed for whether they had a PCR-confirmed positive influenza B test (≥14 days after vaccination) as recorded in their electronic medical record by the end of the influenza season (April 30).

Trial Locations

Locations (1)

Kaiser Permanente Northern California (entire region); 🇺🇸 Oakland, California, United States