Question special
Lead Moderator

As noted in several of the comments, and as described in the study by Jackson et al., more and more investigators and public health agencies are relying on the test-negative study design to monitor influenza vaccine effectiveness at the population level.

What advantages does this approach have over traditional case-control or cohort studies? What are its key limitations?

Is this approach to studying vaccine effectiveness valid for the live attenuated influenza vaccine (LAIV), which relies on local mucosal replication, and thus could impact one's susceptibility to other respiratory pathogens?