doi:10.3390/vaccines8030459engRoy, S.Williams, C.M.Pardo, J.Wijesundara, D.K.Furuya, Y.Impact of pre-existing immunity on live attenuated influenza vaccine-induced cross-protective immunityART-2020-120239The efficacy of the intranasally (i.n.) delivered live attenuated influenza vaccine (LAIV) is variable and, in some seasons, suboptimal. In this study, we report that LAIV exhibits cross-protective efficacy in mice, potentially associated with cellular immunity as opposed to antigen-specific antibody responses. However, pre-exposure to the intramuscularly (i.m.) delivered inactivated influenza vaccine (IIV) severely impaired LAIV-induced cross-protection against heterologous challenge, potentially by inhibiting replication of LAIV. Our findings suggest that pre-existing immunity afforded by IIV suppresses cross-protective T cell immunogenicity of LAIV.2020http://zaguan.unizar.es/record/9580110.3390/vaccines8030459http://zaguan.unizar.es/record/95801oai:zaguan.unizar.es:95801Vaccines 8, 3 (2020), 459 [1-6 pp.]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess