27307
Genome - based reverse vaccinology ( RV ) is a multi - step experimental strategy which starts from in silico analysis of whole genome sequences , from which vaccine candidates can be selected by using bioinformatic algorithms to identify putative protective antigens .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None