Glaxo, Novavax, other drug stocks leap due to swine flu

— -- As concern spread Monday about a swine flu virus outbreak, investors saw opportunity in shares of companies that make or hope to make anti-flu drugs.

The antivirals, which make up the U.S. government's stock of anti-flu drugs, reduce the severity of flu symptoms and may prevent illness. They're seen as the first line of defense in an outbreak.

Longer term, health officials look for new vaccines to ward off outbreaks. Novavax, a Maryland-based company that in 2005 turned its attention to flu vaccines, saw its shares leap 80% Monday.

GSK and Roche also say they're prepared to expand antiviral production. The swine flu outbreak will reinvigorate stockpiling, says Jason Kantor, biotech analyst for RBC Capital Markets. He covers Gilead Sciences, which developed Tamiflu and gets royalties from Roche. The outbreak "raises the awareness that these threats still do exist," he says.