Janet comes to the office complaining of a sore throat, hoarseness, cough, and runny nose. Dr. Porter examines her and explains to her that she has a virus. As she is leaving the office, Janet tells you that she does not understand why Dr. Porter did not give her an antibiotic. Janet's health history is nonsignificant except for her current respiratory tract infection. 1. What reason do you give Janet to explain why Dr. Porter did not prescribe an antibiotic