Investing.com -- Moderna shares jumped nearly 8% in premarket trading on Monday after a U.S. national tested positive for the Andes strain of hantavirus, drawing attention to the company’s early-stage work on a potential hantavirus treatment.

The pharma giant’s stock was up 7.7% in the premarket trade by 05:38 ET.

The Department of Health and Human Services (HHS) said one passenger aboard a repatriation flight had tested mildly positive for the virus, while a second was showing mild symptoms.

All 17 American citizens evacuated from the MV Hondius cruise ship were en route to the United States, HHS said, with the two affected passengers traveling in the aircraft’s biocontainment units "out of an abundance of caution."

Moderna confirmed on Thursday that it was looking into a hantavirus treatment, characterizing its efforts as "early-stage and ongoing" and part of a broader focus on emerging infectious diseases.

The company signed a research agreement with Korea University in 2023 to develop a hantavirus vaccine under its mRNA Access Program.

No approved vaccines or targeted treatments for hantavirus currently exist, and the standard clinical response remains supportive care aimed at keeping patients stable while they recover.

"Research to help us develop vaccines and develop treatments is urgently needed," said Carlos del Rio, former president of the Infectious Diseases Society of America.

The Andes virus, the strain identified among the cruise ship passengers, is endemic to South America, where the vessel originated. Unlike most hantavirus strains, which spread through exposure to the urine, feces, or saliva of infected rodents, the Andes variant is one of the few known to transmit between people, though such cases are rare.