Clinical trial NCT05048589: 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
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
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Influenza
Keywords: Influenza
Vaccination
Pragmatic
Registry
Lead sponsor: Herlev and Gentofte Hospital
Sponsor class: OTHER
Collaborators: name: Sanofi Pasteur, a Sanofi Company
First posted: 2021-09-17
Enrollment: 12551
Sex: ALL
Minimum age (years): 65
Maximum age (years): 79
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Number of persons contacted by recruitment letter
timeFrame: Up to 8 months
measure: Number of participants included and randomized to QIV-HD or QIV-SD
timeFrame: Up to 8 months
measure: Agreement between randomization assignment and actual received vaccine
timeFrame: Up to 8 months
measure: Balance between groups in terms of number of subjects in each arm and baseline characteristics
timeFrame: Up to 8 months
measure: Comparison of baseline characteristics for the QIV-HD and QIV-SD groups to the overall Danish general population aged 65-79 years
timeFrame: Up to 8 months
measure: 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
timeFrame: Up to 8 months
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization for influenza and/or pneumonia
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization for respiratory disease
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardio-respiratory disease
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization for cardiovascular disease
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization from any cause
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for all-cause mortality
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
measure: Description of event rates and calculation of relative vaccine effectiveness for hospitalization for COVID-19
timeFrame: >= 14 days after vaccination up to 8 months post-vaccination
Secondary outcomes:
Other outcomes:
Locations:
city: Hellerup
country: Denmark
facility: Cardiovascular Non-Invasive Imaging Research Laboratory, Department of Cardiology, Herlev and Gentofte Hospital
city: Søborg
country: Denmark
facility: Danske Lægers Vaccinations Service
Study officials:
affiliation: Research Director
name: Tor Biering-Sørensen, MD, PhD, MPH
role: STUDY_CHAIR
References:
citation: Johansen ND, Modin D, Nealon J, Samson S, Salamand C, Larsen CS, Claggett BL, Solomon SD, Landray MJ, Gislason GH, Kober L, Jensen JUS, Sivapalan P, Vestergaard LS, Valentiner-Branth P, Krause TG, Biering-Sorensen T. 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: rationale and design of the DANFLU-1 Trial. Pilot Feasibility Stud. 2022 Apr 21;8(1):87. doi: 10.1186/s40814-022-01044-w.