And there will be those times when we are struggling against the viruses those swarms inside our body system. They are like those parasites living out of us, they make us some sort of medium to live, their habitat, but rather than helping us to be stronger, they drag us down with its venom. Poisonous and amazingly annoying they are, yes. 
Just like our immune system we should be strong, the battle inside ourself is actually a lot more dangerous and risky than the ones we can see. Be strong no matter what.