Health officials in Sitka say there's a rise of "whooping cough" cases in Alaska following a trend moving up the West Coast from California.
Immunization is the best way to combat whooping cough, a highly contagious bacterial infection.
Children as young as two months can be immunized, and it's part of the regular series of vaccinations.
Adults around children also should be immunized.
Officials say babies and small children are more vulnerable, and places where children congregate, like schools and day care centers, are where the highest rates of infections are.