Defining the root cause of reduced H1N1 live attenuated influenza vaccine effectiveness: low viral fitness leads to inter-strain competition

摘要

a Composition of vaccine formulations. Rows detail subtype composition. n/a indicates no strain was present for that subtype. b Ferrets were intranasally vaccinated at Study Day 0 with monovalent, trivalent, or quadrivalent LAIV formulations over a range of doses. Gray arrows indicate major interventions over the 31-day study course. Colored boxes highlight sampling points, with time in days on horizontal axis. Red arrow indicates hourly telemetry recording of core body temperature. *Representative of 2015–16 commercial formulation. d day, A/BOL13 A/Bolivia/559/2013, A/NC99 A/New Caledonia/20/1999, A/SWITZ13 A/Switzerland/9715293/2013, B/BRIS08 B/Brisbane/60/2008, B/PHUK13 B/Phuket/3073/2013, FFU fluorescent focus units, LAIV live attenuated influenza vaccine, NT nasal turbinate.