The first confirmed cases of seasonal influenza have been reported in Spokane, affecting two people.
The seasonal flu is different from the swine flu, which has been in the headlines since last spring and has become a pandemic.
While the swine flu has mostly sickened children and young adults, the seasonal flu is especially serious for people over age 50, adults and children with chronic health conditions, pregnant women in their second and third trimester, and children younger than five.
Health officials continue to encourage vaccination as the best defense against the viral infection.
Though swine flu vaccine shortages have stymied some vaccination efforts, the vaccine against seasonal flu is plentiful and available at many clinics, pharmacies and grocery stores.