The common cold is a name given to minor infections in the nose and throat. All of them are very contagious.
Influenza is a more serious disease caused by viruses that are different from cold viruses.
People catch colds mainly indoors. Being over-tired, in bad shape, and perhaps getting chilled seem to give viruses a better foothold in our bodies. If you have asthma, chronic bronchitis, emphysema, or any other chronic lung illness, you should call your doctor at the beginning of any cold. Usually the tissue heals within two weeks, but sometimes it is damaged. Flu vaccine is made from dead viruses, so no one can get influenza from a flu vaccination.