2741
The HBsAg positive rate in neonates and in infants before two months were 3 % and 2 % respectively .
 Chemical: HBsAg
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: HBsAg