Because the virus is so easily spread, it also changes all the time so your body cannot create defenses against it. Also, the virus spreads all over you body so whenever you t
…ake a breath, you spread it into the air. its contagious so it gets spread really easily Also your body can't make itself immune to colds, because there's so many different colds going around. That's why there's no cold vaccine - it's pointless because you'd have to get about a hundred different vaccines, then your body would probably get ill from them all and there'd still be some colds you could catch. (MORE) 
