a universal vaccine. and abc's david kerley got exclusive access to the headquarters in bethesda, maryland, and has much more. good morning. >> reporter: good morning. nih is one of the country's premiere research hospitals and this team is in the middle of a study which could lead to that universal vaccine, one you wouldn't need every year and we were here and watched as they purposely infected volunteers with the flu. >> that's great, that's fine. >> reporter: in one of the worst flu seasons ever -- >> we picked up the h1. n1 virus. >> reporter: -- dr. matt is preparing to infect three perfectly healthy people with the flu virus including recent college grad emily. you're hoping to solve it down the road that you don't get the flu. >> exactly. for myself and then for young children. >> reporter: nih using its special studies unit where it treated ebola patients paying study participants $3500 to get the flu and be quarantined for at least ten days. what are you helping...