A scoping review of vaccine certificate implementation in Canada and OECD countries during the COVID-19 pandemic: Outcomes and lessons learned.

Vaccine certificates were introduced during the COVID-19 pandemic to document vaccination status, promote uptake and enable safer reopening of society. While these policies supported public health efforts, their implementation raised operational, ethical and legal concerns, sparking debate about their future use in health emergencies. We conducted a scoping review to synthesize the implementation processes, challenges and outcomes of vaccine certificate systems in Canada and other OECD countries. An academic search was conducted in August 2024, across Ovid MEDLINE, Embase and Scopus using controlled vocabulary and key words for sources published from 2020 onward. Grey literature was searched using Google and targeted government and organizational websites. Data were synthesized descriptively and analyzed deductively based on three pre-identified themes - public health, technological, and ethical-legal considerations - derived from the UK Royal Society's framework on COVID-19 vaccine certificate design. The search captured 128 sources (72 academic and 56 gray literature), covering all OECD countries except Chile, Colombia, Costa Rica, Mexico and Norway. Identified subthemes included: (1) purpose and trade-offs; (2) public health, socio-economic and health system impacts, (3) technological infrastructure and data security; (4) equity and accessibility; (5) privacy and surveillance; and (6) public acceptance and trust. Vaccine certificates aimed to support public health goals but posed challenges in digital implementation, particularly in creating secure and interoperable systems and raised concerns around equity, discrimination and privacy. Vaccine certificates show promise for future public health use. However, their success will depend on addressing ethical concerns, ensuring interoperability and strengthening digital infrastructure, regulations and public trust.