Hantavirus Vaccine: Moderna Has Been Developing a Vaccine Since 2023 in Collaboration with a Korean University

The deadly hantavirus outbreak linked to the cruise ship MV Hondius has reignited global interest in vaccines against one of the world's most feared rodent-borne diseases, with Moderna emerging as a key player in an experimental new mRNA-based shot.

The outbreak, tied to the Andes virus strain, the only hantavirus known to spread between humans, has left multiple passengers dead and several others infected after the MV Hondius sailed from Argentina toward Cabo Verde.

Health officials continue to perform contact tracing and monitor survivors as concern spreads over the rare but highly lethal virus. Now, attention is shifting toward whether years of hantavirus vaccine research may be fast-tracked into a pharmaceutical breakthrough – an effective hantavirus vaccine.

Hantavirus and Andes Mortality Rates

Scientists have long cautioned that hantaviruses, especially the Andes strain that is endemic in Argentina and Chile, pose a major pandemic threat due to its human-to-human transmission and high mortality rates. Yet there is no globally approved vaccine for widespread civilian use.

Hantavirus mortality rates vary significantly by type, ranging from less than 1% to as high as 50%. Andes hantavirus (ANDV) is a highly severe strain, with a case fatality rate frequently estimated between 30% and 50%.

The Andes strain of hantavirus causes Hantavirus Pulmonary Syndrome (HPS), a rapid-onset respiratory failure. Research published through the US National Institutes of Health has shown hantaviruses can cause rapid respiratory collapse and kidney failure.

Hantavirus Vaccine Using Moderna mRNA Technology

In 2023, Moderna partnered with the Vaccine Innovation Center at Korea University College of Medicine to develop an experimental mRNA-based hantavirus vaccine under the company's 'mRNA Access' program.

The collaboration became public in 2024 and focuses on creating broader protection against multiple hantavirus strains rather than targeting only one variant.

Researchers involved in the project say current vaccines used in parts of Asia offer incomplete coverage and are largely designed for older hantavirus strains associated with hemorrhagic fever and kidney disease.

The latest effort aims to use mRNA technology similar to Moderna's COVID-19 vaccine platform, allowing scientists to rapidly redesign shots against emerging and more dangerous strains.

Andes and Hantavirus Vaccine Updates

Recent laboratory findings have added momentum to the field. A 2026 study published in Nature Communications found that experimental nucleic-acid-based hantavirus vaccines generated strong neutralising antibody responses in pre-clinical testing, offering hope that modern vaccine platforms may finally overcome years of scientific setbacks.

Meanwhile, researchers at the Vaccine and Infectious Disease Organization are also pursuing next-generation hantavirus vaccines using recombinant vesicular stomatitis virus technology, with studies focusing on protection against Andes virus infections in animal models.

Older NIH-backed research likewise demonstrated that DNA vaccines could successfully trigger protective immune responses against hantaviruses, laying the groundwork for today's mRNA approaches.

Moderna Shares Surge After the MV Hondius Outbreak

The cruise ship outbreak has also fuelled investor speculation. Moderna shares briefly surged after reports linked the company's vaccine research to the ongoing outbreak, although analysts warned the disease remains a relatively small commercial market.

Online discussions have exploded across social media and investor forums, with some users speculating human trials could begin soon while others spread conspiracy theories about vaccine development timelines.

Hantavirus Vaccines in China and South Korea

Chinese and Korean hantavirus vaccines are not used in Western countries like the US or Europe, primarily due to stricter regulatory standards, limited cross-protection against local virus strains, and uncertain effectiveness.

For now, no FDA-approved hantavirus vaccine has reached widespread public rollout. But as the MV Hondius outbreak continues making headlines, scientists warn the crisis may become the moment governments finally take the threat seriously.