Cooler weather means longer sleeves, but public health officials say it's also a sign residents should be rolling up their sleeves to get the annual flu vaccine. The Centers for Disease Control and Prevention recommends anyone 6 months and older be vaccinated for the upcoming flu season and recommends that vaccines be received annually against influenza. Washtenaw County Public Health spokeswoman Susan Cerniglia said the Ann Arbor area has traditionally had very high rates of flu immunization, especially among children. Children younger than 9 years old may require two doses of the season's vaccine.