Vaccination with FluMist involves the administration of attenuated (weakened) viruses into the nose by a sprayer. Some recipients experience low-grade fever, upper respiratory symptoms and muscle aches, but these are generally milder than when a person has a symptomatic influenza infection. Although the vaccine viruses are attenuated in healthy people, there is little information regarding the use of FluMist in people with weakened or compromised immune systems. Therefore, people with weakened or compromised immune systems should not receive FluMist. | 
