https://www.webmd.com/cold-and-flu/cold-guide/common_cold_causes https://www.webmd.com/cold-and-flu/cold-guide/common_cold_ca... The common cold is a low level

https://www.webmd.com/cold-and-flu/cold-guide/common_cold_causes https://www.webmd.com/cold-and-flu/cold-guide/common_cold_ca... The common cold is a low level respiratory infection caused by a known suite of virus candidates. If we made ourselves permanently immune to those without going through the mucus and sore throat part there would be no negative consequences.