Once you get a cold, you will never get that cold again. If the virus changes to a new strain, it can then come back and infect you again.
The changes in strain, and the harbingers of where they will move are the factors used to predict what flu shots will be used in the coming year. It is a lot of science and a bit of guesswork that usually does a good job covering most people for a season. Older Adults are a priority population because of reduced tolerance of illness.
I teach a class called Field Safety with a Sheriff’s Sergeant for mental health workers seeing patients at home. My first question is always “what is the most important thing you can do to keep from being physically compromised and harmed working in the field?” Filling your gas tank, having a charged cell phone, parking safely are common guesses. The answer is, of course, “wash your hands.”
There is another factor involved, and one that is disturbing to medicine watchers. When the guys who do this kind of science call people at home and ask “do you wash your hands after visiting the toilet?” 92 percent says, “Yes!”
If you stand around public rest rooms and count the number of people that do wash their hands, you get a different number. 88 percent of women, only 66 per cent of men wash their hands after exiting the stall. Some places are worse than others. A baseball filed in Atlanta yielded the lowest rate for men (57%) but the highest for women (95%) Bless those Southern Ladies!
By the way, those gels they sell now to sanitize your hands are said to actually work better than soap and water to remove germs. But 20 seconds of soap, water and friction are still the greatest advancement in health in the history of mankind. Use it!