This is a Phase I double-blind, randomized, placebo-controlled study in 43 healthy adolescents and children, 9-17 years of age, inclusive, who are in good health and meet all eligibility criteria.

This clinical trial is designed to assess the safety and immunogenicity of a prime-boost regimen of H3N2 M2SR intranasal influenza vaccine (manufactured by FluGen) followed by licensed inactivated Quadrivalent Influenza Vaccine (QIV) boost administered intramuscularly Subjects will be enrolled in one of two groups in a 1:1 ratio. Arm 1 will receive one dose of M2SR intranasally on Day 1 and one dose of QIV on Day 92. Arm 2 will receive one dose of placebo (saline) intranasally on Day 1, and one dose of QIV on Day 92.

The study duration will be approximately 28 months with patient participation duration approximately 13 months.

The primary study objective is to assess the safety and reactogenicity of a monovalent live attenuated influenza H3N2 M2SR vaccine.