LAIV enhances bacterial load and duration of staphylococcal carriage. LAIV enhances bacterial load and duration of staphylococcal carriage. Groups of 12 to 14 mice were vaccinated with LAIV or PBS vehicle 7 days prior to colonization with S. aureus (S.A.) strain Wright (A and B) or Newman (C and D). S. aureus constitutively expressed luciferase, and bacterial density was measured via IVIS in vivo imaging. Duration of colonization (B and D) was measured via bacterial plating of nasal washes taken daily after the carriage density decreased below the limit of detection for IVIS imaging. Asterisks indicate significant differences between vaccinated and control groups (P < 0.05 by two-sided Student’s t test), and error bars represent standard errors around the mean. Michael J. Mina et al. mBio 2014; doi:10.1128/mBio.01040-13