his guidance provides interim guidance for the integration of SARS-CoV-2 and influenza virologic and genomic surveillance, from sentinel site case enrolment and sampling to the eventual sharing of the virus sequence data, a process known as end-to-end surveillance. This guidance builds on experiences and lessons learned as countries adapted their influenza surveillance systems in the context of the COVID-19 pandemic and reviews new evidence to provide guidance on end-to-end surveillance. The guidance includes new algorithms and strategies to adapt sentinel systems to make them resilient and agile for addressing global and national surveillance needs for influenza and COVID-19.covid-