Families have embraced WAâs new needle-free flu vaccine program, with 75 per cent of immunised children opting for the nasal spray so far this winter. It comes as the State records its best start to the flu season in five years, which health experts say is due in part to an increase in vaccination rates among WA children. So far this year, WA has recorded about 2300 cases, which is more than half the five-year average.