 The show features various references relating to music , media , film , and other pop cultural phenomenon . Character Dr. Edwin Jenner was modeled after the English physician Edward Jenner , a pioneer in the eradication of smallpox . The episode title is an acronym for Test Subject 19 , a patient that was examined by Jenner for clinical research . As " TS @-@ 19 " comes to a close , one can hear the song " Tomorrow Is a Long Time " ( 1971 ) by American singer @-@ songwriter Bob Dylan play in the background . The Washington Post 's Liz Kelly suggested that it could have referred to the seemingly long hiatus that proceeded after the season finale . Jenner later reveals to the group that the symptoms of the walker virus are evocative to that of meningitis . As Rick desperately tries to break out of a nearly incinerating Centers for Disease Control and Prevention building , Carol hands him a grenade , which was the same grenade that Rick had found in a tank in the series premiere , " Days Gone Bye " . The opening and concluding scenes of " TS @-@ 19 " are reminiscent of the American television series Lost . 
