The soft polyester fabric will not change the feel of the mattress.
The waterproof layer has micro pores, which can block liquids, mites and allergens, while letting air pass through, making it breathable and comfortable.
This protective agent does not contain vinyl and is safe for children and pets.
https://www.sleepycare.com/waterproof-mattress-protector/polyester-fabric-waterproof-mattress-cover/all-polyester-soft-waterproof-mattress-cover.html