The COVID-19 Immunity Task Force’s (CITF) mandate includes harmonizing research about COVID-19 immunity to inform Canadian policymakers and support evidence-based decisions. The CITF therefore asks our funded researchers to share three types of research products with the CITF: 1) metadata, 2) results, and 3) where ethically and legally possible, individual-level data. Details are available in our Brief Guide to Sharing Metadata, Data, and Results with the CITF.

The CITF has used the results and individual-level data from studies to inform policymaking throughout the pandemic. Additional value can be realized by making the data from these studies available to researchers around the world for further research via the CITF Databank. Our databank allows mathematical, statistical, and machine learning analyses to explore novel research questions and extract new insights.


Data collected in a standard manner are easier to harmonize, which is a necessary step before analyzing and directly comparing data across multiple studies. To facilitate harmonization and enable the timely use of data from CITF-supported studies, researchers are asked to use Core Data Elements (CDE): a set of standard questions and immunology measures developed by the CITF Secretariat. The CDE have been updated periodically over the course of the pandemic.

Questionnaires for participants

The CDE include questions related to demographics and housing, COVID-19 status, symptoms, risk factors and health behaviours, and vaccination. Questions were based on those asked by Statistics Canada and other national organizations. Our goal was to encourage groups to acquire and record data in a manner consistent with health and social surveys.

Laboratory data reporting

The CDE also include standard reporting formats for serological and cell-mediated immunity assays. Formats were based on international standard coding schemes as much as possible.

Current versions of Core Data Elements

Modules Version number Changes
COVID-19 History and Vaccination Questionnaire 4.1
  • In the vaccine effectiveness section, separate questions for PCR confirmed infections and positive rapid antigen test results.
  • Minor changes (typos, instructions to researchers)
Background Questionnaire (demographics and general health) 2.3 Minor changes (typos, instructions to researchers)
Vaccine Safety Questionnaire 1.0 An optional module introduced in May 2021.
Serologic Assay Results: Guide to Using the Lab Results Data Schema 1.1 Minor changes (typos, instructions to researchers)
Cell-Mediated Immunity Assay Results: Guide to Using Lab Results Data Schema 1.0 New module
Data preparation guide 1.1 Minor changes

See previous versions


These documents describe the legal and ethical conditions and procedures for sharing individual level data.

Data sharing agreement

CITF-supported researchers who can legally and ethically share individual-level data will complete a Data Sharing Agreement similar to this one. Sharing individual-level data is facilitated by ensuring that certain clauses are included in the informed consent materials used for a study.

Informed consent guidance

These documents outline the Minimum Required Consent Elements for contributing individual-level data to the CITF database.

Data preparation

Provides guidance on the creation of shared datasets such as creation of participant ID codes and formatting. Also, outlines the procedure the CITF staff uses to map a study’s collected variables to the CITF core data elements.

Plasma Donor Biobank – Héma-Québec

Given Héma-Québec’s opportunity to collect repeat plasma samples, they have launched a biobank of samples from plasma donors, funded by the CITF. The samples collected allow researchers to gather information before and after vaccination, and in some cases before and after COVID-19 infection, allowing both their researchers and other researchers in Canada to study the immune response to COVID-19 vaccination or infection.

Learn more about using their samples