1908
All 89 participating household members were anti - HIV seronegative , and 78 who were tested were serum p24 antigen negative .
 anti - HIV, serum p24 antigen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 anti - HIV, serum p24 antigen