1) a) You will receive a sick-leave if you have high temperature.
b) You will receive a sick-leave when the doctor diagnoses a serious illness.
2) a) The nurse will give you the injections of anitibiotics after the doctor prescribes (у слова "prescribe" значение "прописать") them.
b) The nurse will give you the injections of antibiotics until the infection process isn't stopped.