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
- Conditions
- Influenza
- Interventions
- Drug: Standard-Dose Quadrivalent Influenza Vaccine
- Registration Number
- NCT05048589
- Lead Sponsor
- Tor Biering-Sørensen
- Brief 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.
- Detailed 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 & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 12551
- Age 65-79 years
- Informed consent form has been signed and dated
- Allergy/hypersensitivity towards the influenza vaccines used in this study
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description High-Dose Quadrivalent Influenza Vaccine High-Dose Quadrivalent Influenza Vaccine QIV-HD single injection at Day 0 Standard-Dose Quadrivalent Influenza Vaccine Standard-Dose Quadrivalent Influenza Vaccine QIV-SD single injection at Day 0
- Primary Outcome Measures
Name Time Method Number of participants included and randomized to QIV-HD or QIV-SD Up to 8 months Agreement between randomization assignment and actual received vaccine Up to 8 months Balance between groups in terms of number of subjects in each arm and baseline characteristics Up to 8 months Number of persons contacted by recruitment letter Up to 8 months 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 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 Description of event rates and calculation of relative vaccine effectiveness for hospitalization for influenza and/or pneumonia >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with a primary (A) diagnosis code for influenza or pneumonia of at least 1 night duration
Description of event rates and calculation of relative vaccine effectiveness for hospitalization for respiratory disease >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with a primary (A) diagnosis code for respiratory disease of at least 1 night duration
Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardio-respiratory disease >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with a primary (A) diagnosis code for cardio-respiratory disease of at least 1 night duration
Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardiovascular disease >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with a primary (A) diagnosis code for cardiovascular disease of at least 1 night duration
Description of event rates and calculation of relative vaccine effectiveness for hospitalization from any cause >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with any diagnosis code of at least 1 night duration
Description of event rates and calculation of relative vaccine effectiveness for all-cause mortality >= 14 days after vaccination up to 8 months post-vaccination Death from any cause
Description of event rates and calculation of relative vaccine effectiveness for hospitalization for COVID-19 >= 14 days after vaccination up to 8 months post-vaccination First hospitalization with a primary (A) diagnosis code for COVID-19 of at least 1 night duration
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (2)
Danske Lægers Vaccinations Service
🇩🇰Søborg, Denmark
Cardiovascular Non-Invasive Imaging Research Laboratory, Department of Cardiology, Herlev and Gentofte Hospital
🇩🇰Hellerup, Denmark