The Swisse brand of vitamins has had a sharp jump in sales in Australasia in the March quarter as people bought products to help their immune systems, and retailers built inventories in case supply chain disruptions worsened.

H&H Group, the Chinese company that bought the Swisse business in late 2015 for $1.7 billion and is listed on the Hong Kong stock exchange, said revenue in the three months ended March 31 in Australia and New Zealand rose 29.3 per cent to 329.5 million Chinese yuan ($71 million).