6308
Army veterans given yellow fever vaccine contaminated with hepatitis B virus in 1942 and controls and ( b ) a case - control study comparing veterans with hepatocellular carcinoma in Veterans Affairs hospitals with matched controls with respect to receipt of contaminated vaccine in 1942 .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities:  
Answer:
 None