(Undated) -- People who live in Fulton County should be aware that there is at least one strain of the flu virus going around that can't be treated with the common flu shot. Public Health spokeswoman Melaney Arnold says the vaccine usually treats at least three strains of the virus but one of them has mutated. That means people who've already gotten a flu shot could still get sick with the H3N2 strain of the flu. But, Arnold says that doesn't mean the vaccine doesn't work. It will still ward off some strains of H3N2 and at least two other strains of the flu. She says getting vaccinated is still the best way to keep from getting sick, along with washing your hands frequently and covering your mouth if you sneeze. It's also a good idea to stay home from work or school if you get sick.