The authors of a new study, published on the bioRxiv* preprint server, constructed a COVID-19 nasal vaccine candidate by inserting a gene encoding the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2, named CA4-dNS1-nCoV-RBD (dNS1-RBD) in a live attenuated influenza virus (LAIV) vector.