Some infections that people identify as common colds are coronaviruses. There's dozens of other viruses that cause colds, with most infections being a different family of viruses (rhinovirus [https://en.wikipedia.org/wiki/Common_cold]).

It's probably not a good idea to make concrete assumptions about a specific virus from the family it belongs to. A good place to look when starting to characterize, not necessarily a complete guide to how the virus will interact with our immune systems.

> is because the cold evolves

The coronaviruses that cause colds (such as CoV-OC43) don't mutate much. Immunity to them doesn't last long for reasons that aren't well understood.

Some other viruses that cause colds escape immunity through mutation, other non-CoV cold causing viruses escape are like CoV and also just have short immunity periods without mutation.

Over 200 different viruses cause common cold symptoms. Only about 15% are coronaviruses. It's usually considered unrealistic to vaccinate for so many different viruses, although there's been some research into vaccinating against a large proportion of them. The Guardian published a good article in 2017:

https://www.theguardian.com/news/2017/oct/06/why-cant-we-cur...