10688
A major liability of existing nicotine vaccine candidates is the wide variation in anti - nicotine immune responses among clinical trial participants .
 Chemical: nicotine; Chemical: nicotine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nicotine; Chemical: nicotine