Feasibility of Randomizing Danish Citizens Aged 65-79 Years to High-Dose Quadrivalent Influenza Vaccine vs. Standard-Dose Quadrivalent Influenza Vaccine in a Pragmatic Registry-Based Setting

Influenza Clinical Trial

— DANFLU-1  

Official title:

Feasibility of Randomizing Danish Citizens Aged 65-79 Years to High-Dose Quadrivalent Influenza Vaccine vs. Standard-Dose Quadrivalent Influenza Vaccine in a Pragmatic Registry-Based Setting

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05048589
• Other study ID #: DANFLU-1
• Secondary ID: QHD000272021-003
• Status: Completed
• Phase: Phase 2
• Start date: October 1, 2021
• Est. completion date: May 31, 2022

Study information

• Verified date: August 2022
• Source: Herlev and Gentofte Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The purpose of the study is to assess the feasibility of identifying, recruiting and randomizing a large sample of Danish citizens aged 65-79 years to high-dose quadrivalent influenza vaccine or standard-dose quadrivalent influenza vaccine in the 2021/2022 influenza season in a registry-based setting using Danish nationwide registries for all data collection including baseline information and outcome assessment.

Description:

To evaluate the feasibility of recruiting and randomizing Danish citizens aged 65-79 years, we aim to randomize 40,000 citizens 1:1 to high-dose quadrivalent influenza vaccine or standard-dose quadrivalent influenza vaccine in a pragmatic, open-label, registry-based design using the infrastructure of Danske Lægers Vaccinations Service (DLVS), an organization responsible for numerous vaccination clinics in Denmark, for recruitment and randomization and Danish nationwide registries for data collection. Citizens will be recruited by DLVS and randomized and vaccinated at the DLVS clinics. All collection of data related to baseline information, outcomes, and safety monitoring will be performed by a central trial site utilizing information from Danish nationwide health registries.

The findings of this pilot trial will indicate whether the conduction of a full-scale, adequately powered pragmatic RCT is feasible within the Danish registry-based framework.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 12551
• Est. completion date: May 31, 2022
• Est. primary completion date: May 31, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 65 Years to 79 Years

Eligibility

Inclusion Criteria:

1. Age 65-79 years

2. Informed consent form has been signed and dated

Exclusion Criteria:

1. Allergy/hypersensitivity towards the influenza vaccines used in this study

Related Conditions & MeSH terms

• Influenza
• Influenza, Human

Intervention

Drug:
• Standard-Dose Quadrivalent Influenza Vaccine
For the control arm, the standard-dose quadrivalent influenza vaccines Influvactetra® and Vaxigriptetra will be used.
• High-Dose Quadrivalent Influenza Vaccine
For the control arm, the high-dose quadrivalent influenza vaccine Efluelda®/Fluzone® High-Dose Quadrivalent will be used.

Locations

Country	Name	City	State
Denmark	Cardiovascular Non-Invasive Imaging Research Laboratory, Department of Cardiology, Herlev and Gentofte Hospital	Hellerup
Denmark	Danske Lægers Vaccinations Service	Søborg

Sponsors (2)

Lead Sponsor	Collaborator
Tor Biering-Sørensen	Sanofi Pasteur, a Sanofi Company

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of persons contacted by recruitment letter		Up to 8 months
Primary	Number of participants included and randomized to QIV-HD or QIV-SD		Up to 8 months
Primary	Agreement between randomization assignment and actual received vaccine		Up to 8 months
Primary	Balance between groups in terms of number of subjects in each arm and baseline characteristics		Up to 8 months
Primary	Comparison of baseline characteristics for the QIV-HD and QIV-SD groups to the overall Danish general population aged 65-79 years		Up to 8 months
Primary	Comparison of baseline characteristics for the QIV-HD and QIV-SD groups to the population aged 65-79 years in the DLVS database used for recruitment		Up to 8 months
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization for influenza and/or pneumonia	First hospitalization with a primary (A) diagnosis code for influenza or pneumonia of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization for respiratory disease	First hospitalization with a primary (A) diagnosis code for respiratory disease of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardio-respiratory disease	First hospitalization with a primary (A) diagnosis code for cardio-respiratory disease of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardiovascular disease	First hospitalization with a primary (A) diagnosis code for cardiovascular disease of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization from any cause	First hospitalization with any diagnosis code of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for all-cause mortality	Death from any cause	>= 14 days after vaccination up to 8 months post-vaccination
Primary	Description of event rates and calculation of relative vaccine effectiveness for hospitalization for COVID-19	First hospitalization with a primary (A) diagnosis code for COVID-19 of at least 1 night duration	>= 14 days after vaccination up to 8 months post-vaccination