Figure 1. Adjusted vaccine effectiveness estimates against any influenza by study and vaccine type for the 2010–2011 through 2014–2015 influenza seasons in children and adolescents 2–17 years of age¹.

Abbreviations: ICICLE, Influenza Clinical Investigation for Children study; IIV, inactivated influenza vaccine; LAIV, live attenuated influenza vaccine; SPSN, Canadian Sentinel Practitioner Surveillance Network; US FLU VE Network, United States Influenza Vaccine Effectiveness Network; %, percentage
¹ For each study in the forest plot, the black circle represents the vaccine effectiveness point estimate and the vertical bar represents the corresponding 95% confidence interval. The 95% confidence interval lower limits are truncated at -40%
²The Canadian SPSN reported unadjusted vaccine effectiveness estimates for children and adolescents 2–19 years of age. SPSN is comprised of sentinel practitioners in the provinces of Alberta (AB), British Columbia (BC), Manitoba (MB), Ontario (ON) and Quebec (QC). LAIV was publicly funded in AB, BC and QC for the 2013–2014 influenza season