<s>[INST] I am in CMF chemo therapy for Breast cancer (no metastasis). I have had 7 treatments and one more to get. I have gotten a minor case of shingles. I also have a fever sore and developed one one a previous treatment. My white counts are always low and I get neuprogen after chemo. Should I get the final chemo treatment or is my immune system going to suffer. I do not want to develop a worse case of shingles or catch the flu etc. Thank you [/INST] Hello, CMF chemotherapy for breast cancer causes lowering of healthy blood cells circulating in body. Thereby, lowering immunity makes the high possibility of contacting shingles when exposed to it. You should start taking treatment of shingles (anti-viral medicines, pain medicines and other symptomatic treatment) with an expert advice and report about the outbreak to your treating cancer doctor team. Most of the time, the next cycle is delayed to avoid further Chat Doctor.  A very good personal hygiene & preventing exposure to infections helps. Hope I have answered your query. Let me know if I can assist you further. </s>