Cost Effectiveness of Influenza Vaccine Choices in Children Aged 2-8 Years in the US

Introduction: Prior evidence found live attenuated influenza vaccine (LAIV) more effective than inactivated influenza vaccine (IIV) in children aged 2-8 years, leading CDC in 2014 to prefer LAIV use in this group. However, since 2013, LAIV has not proven superior, leading CDC in 2015 to rescind their LAIV preference statement. Here, the cost effectiveness of preferred LAIV use compared with IIV in children aged 2-8 years is estimated. Methods: A Markov model estimated vaccination strategy cost effectiveness in terms of cost per quality-adjusted life-year gained. Base case assumptions were equal vaccine uptake; IIV use when LAIV was not indicated (in 11.7% of the cohort); and no indirect vaccination effects. Sensitivity analyses included estimates of indirect effects from both equation- and agent-based models. Analyses were performed in 2014-2015. Results: Using prior effectiveness data in children aged 2-8 years (LAIV=83%, IIV=64%), preferred LAIV use was less costly and more effective than IIV (dominant), with results sensitive only to LAIV and IIV effectiveness variation. Using 2014-2015 U.S. effectiveness data (LAIV=0%, IIV=15%), IIV was dominant. In two-way sensitivity analyses, LAIV use was cost saving over the entire range of IIV effectiveness (0%-81%) when absolute LAIV effectiveness was >7.1% higher than IIV, but never cost saving when absolute LAIV effectiveness was <3.5% higher than IIV. Conclusions: Results support CDC's decision to no longer prefer LAIV use and provide guidance on effectiveness differences between influenza vaccines that might lead to preferential LAIV recommendation for children aged 2-8 years. (C) 2016 American Journal of Preventive Medicine