Regarding covid. Information i've heard!

Hello doctor, My mother was vaccinated on 16 april with covishield. It was her first dosage. On 27 april, she developed symptoms like 1. fever, (99°C- 100°C) 2. little bit cold 3. lost of smell and taste. 4. No weakness or severe cough She is taking PCM whenever fever kicks in.  Taking all her vitamins, basically, following all the covid guidelines. It's already been almost 15 days since her first dosage of vaccine and according to what information i've heard regarding how vaccine works, that the antibodies starts to develop within once body; so is it okay to take ARITHROMYCIN which is an antibiotic and is normally prescribed by doctors to patients during these times as it works for respiratory system. She doesn't have high bp or sugar or any other specific ailments. She is 54. Please help. Regarding this.. Thank you.