Causes of Cold
Common cold is caused by a virus, that has several subtypes. The most common type of virus that causes cold is called Rhinovirus. The infection produces symptoms within 2 to 5 days after contracting it. It is often spread by breathing in virus laden air, that is either coughed or exhaled by an infected person. There are other viruses as well like coronavirus, influenza, which produce similar conditions. Since there are so many types and subtypes, it is not possible to immunize against the common cold.