Moderna stock soars as hantavirus fears spark outbreak trade

Moderna shares surged on Monday as investors rushed into vaccine and biotech stocks following reports of a hantavirus outbreak linked to a cruise ship, despite health authorities maintaining that the overall public health risk remains low.

The stock rose 9.43% to $59.48 in trading after a US national tested mildly positive for the Andes strain of hantavirus.

Moderna shares had already nearly climbed 12% on Friday.

The latest gains extend a sharp rebound for the company’s shares, which have rallied 161% from a 52-week closing low of $22.26 recorded on Nov. 20, 2025.

The rally comes even as experts and analysts caution that the hantavirus outbreak is unlikely to develop into another Covid-19-style pandemic.

Outbreak linked to cruise ship sparks investor reaction

The World Health Organization flagged the outbreak on May 2 after several passengers aboard the Dutch-flagged expedition cruise ship MV Hondius contracted the virus while sailing in the Atlantic.

According to WHO Director-General Tedros Adhanom Ghebreyesus, eight cases have been reported so far, including three deaths. Five of the cases have been confirmed as hantavirus.

The Andes strain involved in the outbreak is significant because it is the only hantavirus species known to allow transmission between humans, according to the WHO.

However, the organization has still assessed the “public health risk as low.”

US health authorities said one passenger on a repatriation flight tested mildly positive for the virus, while another passenger was experiencing mild symptoms.

The Department of Health and Human Services said all 17 American citizens from the cruise ship were en route to the United States.

The two passengers were being transported in biocontainment units “out of an abundance of caution,” according to the department.

The MV Hondius has since docked in Tenerife in Spain’s Canary Islands after spending several days offshore awaiting clearance.

Passengers and crew have begun disembarking under strict health protocols while authorities continue testing, isolation, and repatriation procedures.

US President Donald Trump addressed the outbreak on Friday, saying the situation appeared manageable.

“It’s very much, we hope, under control,” Trump told reporters Thursday. “It was the ship, and I think we’re going to make a full report about it tomorrow. We have a lot of people. ... It should be fine.”

Moderna leads gains among biotech stocks

Investors quickly focused on companies perceived to be best positioned to respond to a potential outbreak.

Moderna gained after confirming that it was conducting early-stage research related to hantavirus treatments and vaccines.

“Moderna has conducted preclinical research on Hantaviruses in collaboration with the US Army Medical Research Institute of Infectious Diseases (USAMRIID), reflecting the ongoing regional impact of these pathogens,” the company said in a statement shared with CNBC.

“These efforts are early-stage and ongoing and reflect Moderna’s broader responsibility to develop countermeasures against emerging infectious diseases.”

Other biotech and vaccine-related stocks also moved higher. Inovio Pharmaceuticals, Novavax, and Emergent BioSolutions also rose earlier in the session though some of them pared gains at the time of writing.

The market reaction reflected growing investor interest in companies associated with infectious disease response capabilities, particularly those with established vaccine platforms following the Covid-19 pandemic.

Analysts see sentiment-driven rally

Despite the strong gains, analysts have questioned whether the outbreak presents any meaningful commercial opportunity for vaccine makers.

Evercore ISI said last week that the hantavirus situation was unlikely to become a significant revenue driver for Moderna.

“As a heavily retail-trafficked name, [Moderna] tends to trade on outbreak headlines well beyond the underlying commercial implications,” Evercore analysts said in the note published on May 7. “With regards to current headlines, we see no meaningful revenue opportunity.”

The analysts added that the market for hantavirus treatments remains structurally limited.

“Hantavirus is a low-incidence, structurally small market, and we view any potential outsized moves as sentiment-driven, not fundamental. At most, it reinforces Moderna’s mRNA platform agility, something already well understood post-COVID,” they added.