I have yet to hear anyone provide any credible evidence of any virus showing up on an iPhone. The bottom line is to be aware of any strange/unusual requests to download an unknown application or accepting permissions. There are applications that can be downloaded if you are concerned, but I don't think they are necessary.
I Have been researching on this specific topic from the last few weeks and found this article some helpful! Can iPhone get a virus
But I still have some confusion that how can an iPhone get a virus because they have one of the most secure systems in the world! Or there are no viruses created for iPhones? What's the reason behind it?