The invention is directed to novel live attenuated influenza virus (LAIV) vaccines comprising one or more microRNA (miRNA) Response Element(s) (MRE) within an influenza virus genome. The MREs useful for the present invention can be derived from any miRNA which is highly expressed in influenza-targeted cells of an animal in need of vaccination but are not expressed or are expressed at very low levels in species (e.g., embryonated chicken eggs) or cell lines used for a large-scale vaccine production. This allows efficient vaccine production but renders the vaccine virus susceptible to attenuation in the influenza-targeted cells of vaccinated animals expressing a cognate miRNA.
