Already this year, 305 South Australian children have been diagnosed with the flu, with 28 of those ending up in hospital.

Across the state there have been 2368 reported cases of the flu – an increase of 14 per cent compared to the same time last year. Hospitalisations are also up, from 251 to 268.

Children aged under 5 are particularly vulnerable, however at this stage only 5.7 per cent of young people in this age group have been vaccinated against the flu.

The rising cases and low uptake of the vaccine has prompted the state government to launch a new campaign with the key message 'Stop the flu before it stops them', aiming to lift vaccination rates among vulnerable at-risk groups.

Through the National Immunisation Program, the flu vaccine is free for children under 5 years of age, pregnant women, over 65s, Aboriginal and Torres Strait Islander South Australians and people with pre-existing health conditions.

South Australia's Chief Public Health Officer Professor Nicola Spurrier encouraged parents to get their children vaccinated.

"Vaccination is the best protection against the severe consequences of the flu which is why I encourage everyone to get vaccinated as soon as possible," Professor Spurrier said.

She said other behaviours that can help keep people safe with the onset of the colder weather includes covering coughs and sneezes, hand washing and not going out and about or to work when sick.

A Respiratory Syncytial Virus (RSV) monoclonal antibody medication is also being rolled out for the highest risk infants in the state, to further protect vulnerable babies and children from respiratory illness this winter.

In the coming weeks, babies identified to meet the risk will be invited to receive RSV immunisation at the Women’s and Children’s Hospital or Flinders Medical Centre.

For more information, visit Stop the flu.