The reporting completeness of a passive safety surveillance system for pandemic (H1N1) 2009 vaccines: A capture-recapture analysis

► Reporting completeness for Guillain-Barré syndrome after 2009 H1N1 vaccination was 40%. ► The estimated number of Bell's palsy in the 0-42 days after vaccination compared with the expected was 1.48 (95% CI 1.11-1.98). ► The capture-recapture method can be used to enhance safety surveillance for other vaccines.