Short answers, pulled from the story.
The common cold is the most frequent infectious disease in human history and a viral infection of the upper respiratory tract. The average adult experiences two to three infections annually while children may suffer six to eight colds a year.
A vaccine for the common cold remains a scientific impossibility because well over 200 virus strains are implicated in causing the disease. The rhinovirus alone has 99 known serotypes and these viruses mutate rapidly and vary so widely that creating a broadly effective vaccine is highly improbable.
The Common Cold Unit was set up by the Medical Research Council in the United Kingdom in 1946. It was here that the rhinovirus was discovered in 1956, marking a pivotal moment in understanding the disease.
The common cold accounts for over 20 billion dollars in annual costs in the United States alone. This figure includes 75 to 100 million physician visits and over 20 billion dollars in cold-related work loss which accounts for 40 percent of time lost from work.
Normal exposure to cold does not increase one's risk of infection but severe exposure leading to significant reduction of body temperature known as hypothermia may put one at greater risk. The prevalence of many such viruses is indeed seasonal occurring more frequently during cold weather due to factors like low humidity and social shifts.
Zinc supplements may shorten the duration of colds by up to 33 percent and reduce the severity of symptoms if supplementation begins within 24 hours of the onset of symptoms. However some zinc remedies directly applied to the inside of the nose have led to the loss of the sense of smell.