Whooping cough has reached epidemic proportions in parts of Australia.
The ABC reports there have already been more than 14,000 cases of the disease this year - the most ever recorded.
New South Wales has had 8000 cases so far this year compared to 7000 in total last year.
Whooping cough is highly contagious and potentially fatal.
Infectious disease specialists are calling for a nationwide adult vaccination program to stop the spread of the disease, technically called 'pertussis'.
The rise in infections has led NSW, Victoria and the Northern Territory to offer free vaccines for adults who care for young children.
The National Centre for Immunisation Research and Surveillance says adult vaccination is vital in order to protect the very smallest of babies who are most at risk of dying - that's the ones under two months old.
Professor Robert Booy says whooping cough rates will eventually drop, but Australia is not yet out of the danger period.
He says pertussis "really peaks" about every three years and "this problem isn't over yet," he said.