That's what I said. Ony jailbroken iPhones, at this time (that I am aware of), have shown malware, and then only rarely.
However, the only reason that non-jailbroken iPhones have yet to show signs of malware is because Apple only allows certain apps in the App Store, after extensive analysis. It doesn't mean that malware cannot get onto your iPhone; it simply means that Apple has been successful, so far, in preventing it via authorized downloads.
Is that system infallible? Of course not. But to say that malware cannot run on an iPhone is incorrect. Just like any OS, iOS could be affected. There's nothing magical about Apple products that inherently protects them from malware. It's just that getting past the Apple security & standards is so difficult, than hackers don't usually bother. Especially since it's cheaper & easier to construct malware for Androids, for example.