Overview
The purpose of this pragmatic randomized trial is to evaluate the relative vaccine effectiveness of high-dose quadrivalent influenza vaccine (QIV-HD) vs. standard-dose quadrivalent influenza vaccine (QIV-SD) in older adults. Participants will be randomized 1:1 to either QIV-HD or QIV-SD.
Description
The study is a pragmatic, registry-based, open-label, active-controlled, individually randomized trial. The Danish nationwide administrative health registries will be used for data collection including baseline information, follow-up data, and safety monitoring. The study aims to randomize 286,900 participants over 3 influenza seasons. In each season, participants will be individually randomized 1:1 to receive either QIV-HD or QIV-SD.
Eligibility
Inclusion Criteria:
- Age 65 years and above (this inclusion criterion will be modified according to the Danish government's official recommendations for the 2022/2023 and 2023/2024 influenza seasons)
- Informed consent form has been signed and dated
Exclusion Criteria:
- There are no specific exclusion criteria for this study