Accidents will happen and sometimes they just cannot be avoided, especially if someone is sick on the sofa.
Prevention is better than the cure and when you are allowing your kids and pets to share your expensive furniture it is very important to protect the fabric with a stain protector.
If, for any reason, your sofa was never protected from day one, you could be looking at permanent staining and damage.
Here is an example of when I had a callout to an address in Camberley, Surrey. The cushion had a light coloured stain which was caused by a domestic carpet cleaning foam. This will never remove vomit!
I had to use a special cleaning solution which chemically breaks down the bacteria and soiling, followed by hot water extraction to flush out the contaminates.