Current influenza vaccines often do not provide protective immune responses in vulnerable populations such as pediatric patients, the elderly and the immunocompromised. One approach to improve influenza vaccines is to include adjuvants, substances that trigger the first line of defense of the immune response (the so-called innate, or nonspecific, immunity), which in turn helps boost and shape the pathogen-specific immunity. With this project, we aim to investigate whether bacterial lysate extracts can specifically improve immune responses to intranasal vaccination. The expected results will support the further development of broadly protective influenza vaccines that will have large benefits on global health.