just a quick note I had dengue fever many years ago which led me down a path to ill health hell. It almost took me down I think in combo with all the vaccinations I had thru out my life and world travel etc. The only thing that help me over come it was Acupuncture to rebuild my immune system for many the results are amazing and no side effects very safe for someone like your dad he does not even have to do the herbs to strengthen immunity.
I also do rife and Iodine (very gently)
I do not think u should be tempted by Miracle-Mineral-Supplement that was a huge mistake for me and set me back about 6 years it was a horrific experience!
Anyway it would most likely take 2-3 months of TX but so safe and gentle with such profound effects