Most people think that the immune system is destroyed because of viruses and germs. Those have been with us for millions of years. The immune system is destroyed because our vitality is gone. Why is our vitality gone? There is pollution in the earth, in the air, in the oceans, everywhere, and we are doing wrong things with our sex, and using drugs, marijuana, hashish, and so on. The etheric body is weakened, and weakened in such a way that it has no protection. You are going to protect your etheric body by living a clean life and living in clean places, if you can find them.
You are going to develop virtues and render service if you want to develop your etheric body. The etheric body is damaged when you use alcohol, marijuana, and drugs and also when dealing in prostitution. Avoid as much as you can electrical instruments. If you want to commit suicide, sleep under an electric blanket. Through all these you really destroy your etheric body, and then your immune system is destroyed.
Esoteric Science of Healing