You may not realize it, but you harbor Streptococcus pneumoniae. It lives in your nose, among other places in your body. KILL IT WITH FIRE!
Not a good idea, as it’s generally harmless. Hemophilus influenzae also inhabits your airways, and the neighbors aren’t exactly friendly. In fact, they’re pretty much constantly at war. H. influenzae occasionally commandeers your white blood cells to attact S. pneumoniae, but S. counters sometimes with thickened coatings that, while expensive energy-wise to produce, prevents it from being killed.
And that’s where the trouble starts. Having protected itself from your immune system, it moves deeper into your respiratory system. That can killyou.
In defending itself from a competitor, S.pneumoniae inadvertently becomes an armoured killer.
You’re not the taget, just collateral damage. Not that it matters much, because you’re still dead. But, it’s nothing personal.