The threat of a pandemic triggered by a new 'flu strain that has killed 103 people in Mexico will provide a windfall for some makers of drugs and vaccines.

Shares in Australia's Biota Holdings Ltd , whose inhaled 'flu drug Relenza is licensed to GlaxoSmithKline Plc , soared 82 percent on Monday.

Relenza, known generically as zanamivir, is one of two drugs, along with Roche Holding AG's Tamiflu, or oseltamivir, that have been shown to work against the new 'flu strain, which has spread to the United States and as far as New Zealand.

Tamiflu, given as a convenient tablet, is expected to be in greatest demand and shares in Roche were indicated 3.5 percent higher in Zurich on Monday morning.

Tamiflu was originally invented by U.S. biotech company Gilead Sciences Inc .

The 'flu outbreak, which poses the biggest risk of a large-scale pandemic since avian 'flu surfaced in 1997, will also fuel demand for vaccines from major producers like Sanofi-Aventis SA , Glaxo, Novartis AG and Baxter International Inc , although making ones against the new strain will take months.

Shares in U.S. biotech company Novavax Inc , which is working on new types of vaccines, jumped 75 percent on Friday.

(Reporting by Ben Hirschler; Editing by Greg Mahlich)