A spate of meningococcal cases has been reported on South Australia's traditional lands.
SA Health says an 11-year-old boy and a three-year-old girl were confirmed to have contracted the W strain of the disease this week while a four-year-old boy was diagnosed last week.
All three were living on the Anangu Pitjantjatjara Yankunytjatjara lands, in SA's north, prompting authorities to offer free vaccines to all residents.
"To reduce the likelihood of any further cases, we're working with local Aboriginal community health care services to implement an immunisation program for all residents of the APY Lands," acting chief medical officer Nicola Spurrier said.
"People aged one to 19 years will be the first to receive the vaccination against meningococcal strains A, C, W and Y as part of the program."
Professor Spurrier said meningococcal infections were fairly rare and only passed person-to-person by close and prolonged contact.
But she said it was important for people to be aware of the symptoms including fever, headache, difficulty looking at bright lights, stiff neck, confusion, drowsiness, vomiting, sore muscles, or a purple rash.