"Crude Vaccine Effectiveness" Is a Misleading Term in Test-negative Studies of Influenza Vaccine Effectiveness

Sheena G Sullivan¹, Benjamin J Cowling

• ¹WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia, Fielding School of Public Health, University of California, Los Angeles, CA, USA, sheena.sullivan@influenzacentre.org WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.