A reported outbreak of hantavirus linked to the MV Hondius cruise ship has coincided with stock movements for several pharmaceutical companies and renewed attention on vaccine research. The World Health Organization (WHO) has assessed the public health risk as low.
Hantavirus Outbreak and Response
Health authorities are investigating a cluster of hantavirus cases among individuals associated with the Dutch-flagged cruise ship MV Hondius. As of recent reports, a total of eight cases have been identified.
Source 1 states that as of May 8, 5 cases are confirmed and 3 are suspected, with 3 deaths reported. Source 3 reports that the WHO has classified six infections as confirmed and two as probable, with three fatalities. The strain involved has been identified as the Andes virus, which is capable of human-to-human transmission, though this is reported as not common.
"The strain involved has been identified as the Andes virus, which is capable of human-to-human transmission, though this is reported as not common."
The vessel, which departed from Argentina last month, is currently traveling toward the Canary Islands with remaining passengers on board. Spain’s Health Minister Monica Garcia stated that the ship is expected to dock in Tenerife within three days and that those still on board were not presenting symptoms.
Several individuals were evacuated from the ship. According to the vessel operator Oceanwide Expeditions, two passengers in serious condition were evacuated to the Netherlands for treatment, along with a third individual not currently showing symptoms. The evacuated individuals include a British national, a 65-year-old German, and a 41-year-old Dutch crew member. Source 3 adds that among 17 American passengers evacuated, the U.S. Department of Health and Human Services (HHS) identified one who tested positive for the Andes strain and a second with mild symptoms; both were placed in biocontainment units during the flight.
U.S. President Trump stated that the outbreak is under control and that a full report is forthcoming. The origin of the outbreak remains unknown, and it is unclear if individuals other than ship passengers have been infected. No approved vaccine or targeted antiviral treatment exists for hantavirus; only supportive care is available.
Impact on Pharmaceutical Stocks and Research
Moderna (NASDAQ: MRNA) saw a notable increase in its stock price. Source 3 reports that the stock rose 9.3% to close at $53.05 on Friday, after climbing as much as 20% intraday, and gained an additional 7.7% in premarket trading on Monday. Source 2 reports a 10% increase on Thursday.
The stock movement coincided with two developments:
- Hantavirus Research: Moderna confirmed it has been conducting early-stage vaccine research on hantaviruses in collaboration with the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and with the Vaccine Innovation Center at Korea University College of Medicine. The company stated these efforts are early-stage and ongoing. Evercore ISI stated that the outbreak is unlikely to be a significant revenue opportunity for Moderna, characterizing the stock movement as sentiment-driven.
- Flu Vaccine Results: Moderna announced the publication of positive Phase 3 clinical trial results for its seasonal influenza vaccine candidate, mRNA-1010, in the New England Journal of Medicine. The study evaluated the vaccine in adults aged 50 years and older. Source 3 reports that mRNA-1010 achieved a relative vaccine efficacy of 26.6% compared to a standard-dose seasonal flu vaccine in adults 50 and older, and 27.4% in those 65 and older. Regulatory submissions are under review in the U.S., Europe, Canada, and Australia, with an FDA goal date of August 5, 2026.
Other pharmaceutical companies, including Inovio Pharmaceuticals, Novavax, and Emergent BioSolutions, also experienced stock gains of around 1% after earlier surges, according to Source 1.
Additional Vaccine Development
An international team of scientists from the University of Bath, the United States, and South Africa is working on a hantavirus vaccine. The virus is typically spread by rodents.