COVID-19 Vaccine Grey Literature Resources

Vaccine grey literature resourcesA Curated List of Evidence-Based Sources for Health Professionals, Librarians, and Researchers.

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This report was updated on March 7, 2022.

To produce this report, CADTH used a modified approach to the selection, appraisal, and synthesis of the evidence to meet decision-making needs during the COVID-19 pandemic. Care has been taken to ensure the information is accurate and complete, but it should be noted that international scientific evidence about COVID-19 is changing and growing rapidly.

Cite As: COVID-19 Vaccine Grey Literature Resources. A Curated List of Evidence-Based Sources for Health Professionals, Librarians, and Researchers. Ottawa: CADTH; 2022 March.


This COVID-19 vaccine grey literature resource was developed collaboratively by the Public Health Agency of Canada’s (PHAC) National Advisory Committee on Immunization Secretariat and CADTH’s Research Information Services team. The resource highlights freely accessible evidence-based sources of grey literature on this topic. Grey literature includes government information and reports that are not published commercially and that may be inaccessible via bibliographic databases.


This resource list is intended for use by health professionals, librarians, and information specialists, as well as National Immunization Technical Advisory Groups and the health technology assessment research community seeking information specific to COVID-19 vaccines.


The COVID-19 vaccine grey literature resource is a compilation of information sources related to regulatory approval, adverse effects, public health guidance, clinical studies, uptake, and evidence reviews of COVID-19 vaccines. The resource list is organized by topic and jurisdiction. This is not an exhaustive list of resources on this topic, and it does not cover consumer health information. The list prioritizes Canadian resources, English and French language material and high-quality public health guidance and knowledge syntheses. It will be updated regularly as new resources become available. Because of the continuously evolving nature of the internet, CADTH cannot be held responsible for occasional inaccuracies due to website changes.

How to Use

The resource list can be used to document all aspects of the search process. This includes the documentation of keywords used in the search and information about the availability of each website, as well as the use of a dropdown box beside each website to indicate the success or relevancy of the retrieval.

Use the dropdown boxes that appear beside each website in the list to indicate one of the following:

  • searched; nothing found
  • not searched; not relevant
  • searched; results found
  • results may be of peripheral interest.

Use the space below each link to document the search terms used on the individual websites listed or to make other notes.


This document was informed by a preliminary checklist developed at PHAC. The following experts reviewed and provided feedback on a draft of this document:

  • Katherine Merucci from the Health Canada Library.
  • Nicole Forbes, Joshua Montroy, Matthew Tunis, Kelsey Young, and Joseline Zafack from PHAC.