The cost effectiveness of influenza vaccination in children aged 2-8 years is highly dependent on vaccine effectiveness; the vaccine type with higher effectiveness is preferred. In general, exclusive IIV use is preferred over LAIV use, as long as vaccine effectiveness is higher for IIV than for LAIV.
Prior studies showed that live attenuated influenza vaccine (LAIV) is more effective than inactivated influenza vaccine (IIV) in children aged 2-8 years, supporting the Centers for Disease Control and Prevention (CDC) recommendations in 2014 for preferential LAIV use in this age group. However, 2014-2015 U.S. effectiveness data indicated relatively poor effectiveness of both vaccines, leading CDC in 2015 to no longer prefer LAIV.
Using published meta-analysis vaccine effectiveness data (83% LAIV and 64% IIV), exclusive LAIV use would be a cost-effective strategy when vaccinating children aged 2-8 years, whereas IIV would not be preferred. However, when 2014-2015 U.S. effectiveness data (0% LAIV and 15% IIV) were used, IIV was likely to be preferred.
An age-structured model of influenza transmission and vaccination was developed, which incorporated both direct and indirect protection induced by vaccination. Based on this model, the cost effectiveness of influenza vaccination strategies in children aged 2-8 years in the U.S. was estimated. The base case assumed a mixed vaccination strategy where 33.3% and 66.7% of vaccinated children aged 2-8 years receive LAIV and IIV, respectively. Analyses were performed in 2014-2015.