Get A Flu Vaccine. Getting a seasonal flu vaccine is a great way to protect yourself against the flu viruses going around each year. Head to your doctor early on in flu season (as soon as the vaccine is available) and get yourself vaccinated. It’s one of the most effective ways to prevent flu. Studies have found that in healthy adults, the flu vaccine can decrease the chances of coming down with the flu by as much as 70 percent to 90 percent. But unfortunately, the flu vaccine can’t completely prevent flu in everyone. Though there’s still a chance you could get sick, the flu vaccine can lessen the severity and duration of your symptoms.