what's wrong with leeches?
they secrete an enzyme that helps with blood clotting and eat tissue with the bacteria or disease agent and cleanse old wounds of dead flesh so that the body can heal by creating new flesh and not having to deal with the old dead tissue in the way.
as for the flu shot. I would trust God in it. Its your body, God will protect His people, even to the extent that poison will not kill you before your time if you are doing God's will and not out of selfish interest and concern for self.
there are a lot of different flu shots. the flu mist is a live attenuated virus. the flu shot is typically a dead or inactivated virus. your bodies immune system produce memory cells and all you really save is time when the flu virus enters your system
its not about if you will catch the flu, but whether your body will be strong enough to resist the virus once it enters your body. whether you will become sick because of it.
I think our physical body models for us what is happening in the spiritual realm. not that sick people are sinful but how we are to fight the spiritual body can be taught by how God has equipped us with physical bodily defenses to fight off physical attacks.
for example the pathogen enters the body in a point of entry/ sin enters by either our eyes seeing and lusting after something or our pride being pricked and us becoming made or our flesh craving for things God did not already give us.
next we can either recognize it as abnormal and not in God's plan or we can ignore it and allow it to spread like cancer or infected cells/virus
reminds me of these Bible verses:
wow sorry my mind went blank...
James 1
12 Blessed is the man who endures temptation; for when he has been approved, he will receive the crown of life which the Lord has promised to those who love Him. 13 Let no one say when he is tempted, “I am tempted by God”; for God cannot be tempted by evil, nor does He Himself tempt anyone. 14 But each one is tempted when he is drawn away by his own desires and enticed. 15 Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death.
16 Do not be deceived, my beloved brethren. 17 Every good gift and every perfect gift is from above, and comes down from the Father of lights, with whom there is no variation or shadow of turning. 18 Of His own will He brought us forth by the word of truth, that we might be a kind of firstfruits of His creatures.
Sin is like a virus we should recognize it and reject it but too often it disguises itself as an enveloped virus and pretends to be one of our own cells. However just as God gave our physical bodies ways to resist and fight off physical illness He shows us how to STAND and overcome spiritual illness as well.
sorry i have a headache. not sure if i'm making any sense.
God bless you and keep you.
remember this physical body is but a temporary vessel that will be discarded. we care for it because our bodies are temples to our Most High God and we are His creation and out of love of Him we care for ourselves too. However, if we pray about it all things are lawful but not all helpful or edifying. you have to ask God what to do. I do not believe taking the flu shot will harm or help you physically if your immune system is strong. but then drinking spiritual poison would not either if you have the discernment to know truth from lies, good from evil.