ABSTRACT
INTRODUCTION: The COVID-19 pandemic represents a threat that has posed a challenge to public health response and threatens immunization programs globally. Despite recommendations to continue routine immunization services, disruptions have been observed to these and mass vaccination campaigns. This may result in setbacks to immunization initiative successes and a rise in cases of vaccine-preventable diseases. AREAS COVERED: We conducted a systematic literature review to identify studies globally that described how indicators of health system resilience, defined using the Resilient Health System Framework, enabled routine immunizations to continue during the COVID-19 pandemic. A systematic search was conducted in Embase, Web of Science, PsychInfo, medRxiv, bioRxiv, and the gray literature between 1 January 2020, and 12 November 2021. Information was extracted from the studies identified describing how the specific elements of resiliency (being aware, diverse, self-regulating, integrated, and adaptive) were applied to their routine immunization programs. EXPERT OPINION: Our study demonstrates the use of tools that contributed to immunization program resilience during the COVID-19 pandemic in all geographic regions and for countries with different income levels. These tools may help inform preparations for other immunization programs to catch up from the COVID-19 pandemic or mitigate the impact of future threats.