A Phase IV Vaccine Study Under the National Cohort Study of Effectiveness and Safety of SARS-CoV-2 (COVID-19) Vaccines.

Overview

A phase IV study to assess if the SARS-CoV-2 vaccine from Johnson \& Johnson/Janssen (J\&J) results in change in number and activation of platelets and anti-PF4 Level. As well as compare whether the vaccine is causing a greater activation of platelets and anti-PF4 than the mRNA vaccines. The Danish Medicines Agency has approved the vaccine from J\&J for use in Denmark, however it is not currently part of the national vaccine programme. The design is an open-labelled, non-randomised, parallel group, phase IV study with historical controls. A sub-study will be embedded within this master protocol addressing basic and translational research questions requiring additional sampling of biological material (under separate participant informed consent).

Participants will have 3 specific study visits and will hereafter be followed for 2 years after the vaccination with regular visits after 3, 6, 12 and 24 month. In this way the participants will be offered an extra close follow up on vaccine effectiveness. Safety data will be collected at study visits until 3 months after the first vaccination,, with additional safety data collected under this protocol during the first month after vaccination. Research samples will be collected at each study visit during the two-year follow-up.

Conditions