Extra stock of a steroid drug will be flown into the country to help battle a spike in the respiratory virus RSV.

Monthly demand for prednisolone almost doubled to 150,500 bottles in June.

Pharmac's worked with suppliers, the Trade Ministry, Customs and Ports of Auckland to fast-track our access to already ordered supplies.

Director of operations Lisa Williams told Heather du Plessis-Allan more will be delivered by airfreight by the end of the month.

“We like to have three months supply available at any one time to manage increases in demand that might occur. Those supplies were at risk.”

Pharmac have said the supply of prednisolone is critically low in New Zealand due to the increase in demand.

More will be air-freighted in by the end of the month.

LISTEN ABOVE