I am nearly 2 years out from chemo and I am taking Letrozole. I reassured everyone that I was fine and that my immune system would have recovered but did decide to check with the oncology clinic. Turns out that I am not so fine and that my white cell count is still sitting below the preferred range based on blood test done in late Feb and sometime late last year. I get the impression that it is still recovery from chemo which can take much longer than expected. I too work in a school and decided that it wasn't worth the risk. I was going to go back once the students left but my GP said not to. Unfortunately, not getting any support from school regarding working from home so feeling less than thrilled (and very, very bored). However, I have fought too hard to try to claw my way back to some semblance of health since treatment to risk anything.