2543
Differential impact of immune escape mutations G145R and P120T on the replication of lamivudine - resistant hepatitis B virus e antigen - positive and - negative strains .
 lamivudine, hepatitis B virus e antigen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 lamivudine, hepatitis B virus e antigen