This study is an extension to Study ALT-103-201 to evaluate the immunogenicity of NasoVAX administered by intranasal spray at a single dose of 1×1011 vp at Day 366 (± 60 days). Up to 15 subjects who received NasoVAX at the 1×10(11th) vp dose in Study ALT-103-201 will be screened, and a serum sample will be collected from each eligible subject for evaluation of influenza HAI assay against influenza A/California/07/2009(H1N1), a strain homologous to the one used for NasoVAX (monovalent AdcoCA09.HA). Ad5 antibody neutralization assay may also be performed.