Can routinely collected laboratory and health administrative data be used to assess influenza vaccine effectiveness? Assessing the validity of the Flu and Other Respiratory Viruses Research (FOREVER) Cohort.

•We created the FOREVER Cohort by linking individual-level laboratory and administrative data.•We assessed the presence and magnitude of information and selection biases in these data.•Influenza vaccine effectiveness (VE) estimates were similar under a range of conditions.•VE estimates were higher when accounting for misclassification of vaccination status.•FOREVER Cohort VE estimates were comparable to those from other studies.