The common cold during the winter is rarely influenza.  Influenza lasts longer, typically 10 days, and is more severe than the common cold.  Yet, in common usage nearly every short-term cold is called the flu, including here in California the stomach flu.  Testing shows that influenza isn’t common with the exception of children.  Children because of their lack of exposure to influenza virus and other bacteria at a much higher risk than their parents of catching a cold and getting the  flu.  So other than giving a flu shot to school kids, it is not a good choice to be vaccinated, as the below article confirms.   

http://summaries.cochrane.org/CD001269/vaccines-to-prevent-influenza-in-healthy-adults

Vaccines to prevent influenza in healthy adults

Jefferson T, Di Pietrantonj C, Rivetti A, Bawazeer GA, Al-Ansary LA, Ferroni E

Published Online:

July 7, 2010

Over 200 viruses cause influenza and influenza-like illness which produce the same symptoms (fever, headache, aches and pains, cough and runny noses). Without laboratory tests, doctors cannot tell the two illnesses apart. Both last for days and rarely lead to death or serious illness. At best, vaccines might be effective against only influenza A and B, which represent about 10% of all circulating viruses. Each year, the World Health Organization recommends which viral strains should be included in vaccinations for the forthcoming season.

Authors of this review assessed all trials that compared vaccinated people with unvaccinated people. The combined results of these trials showed that under ideal conditions (vaccine completely matching circulating viral configuration) 33 healthy adults need to be vaccinated to avoid one set of influenza symptoms.  In average conditions (partially matching vaccine) 100 people need to be vaccinated to avoid one set of influenza symptoms. Vaccine use did not affect the number of people hospitalised or working days lost but caused one case of Guillian-Barré syndrome (a major neurological condition leading to paralysis) for every one million vaccinations.  Fifteen of the 36 trials were funded by vaccine companies and four had no funding declaration. Our results may be an optimistic estimate because company-sponsored influenza vaccines trials tend to produce results favorable to their products and some of the evidence comes from trials carried out in ideal viral circulation and matching conditions and because the harms evidence base is limited [in other words, vaccination don’t work for the flu. [Other studies have a similar negative conclusion, especially among the elderly because their immune system response to a vaccination is about what half that of a person in their 20s.]

http://summaries.cochrane.org/CD001269/vaccines-to-prevent-influenza-in-healthy-adults