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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
12,551
For the control arm, the standard-dose quadrivalent influenza vaccines Influvactetra® and Vaxigriptetra will be used.
For the control arm, the high-dose quadrivalent influenza vaccine Efluelda®/Fluzone® High-Dose Quadrivalent will be used.
Cardiovascular Non-Invasive Imaging Research Laboratory, Department of Cardiology, Herlev and Gentofte Hospital
Hellerup, Denmark
Danske Lægers Vaccinations Service
Søborg, Denmark
Number of persons contacted by recruitment letter
Time frame: Up to 8 months
Number of participants included and randomized to QIV-HD or QIV-SD
Time frame: Up to 8 months
Agreement between randomization assignment and actual received vaccine
Time frame: Up to 8 months
Balance between groups in terms of number of subjects in each arm and baseline characteristics
Time frame: 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
Time frame: 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
Time frame: Up to 8 months
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
Description of event rates and calculation of relative vaccine effectiveness for all-cause mortality
Death from any cause
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
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
Time frame: >= 14 days after vaccination up to 8 months post-vaccination
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.