A New Hantavirus Vaccine Is in the Works
US-based pharmaceutical company Moderna confirmed that it is working on developing hantavirus vaccines in collaboration with the Vaccine Innovation Center at the University College of Medicine of Korea (VIC-K). This comes after a hantavirus outbreak occurred on a Dutch cruise ship from Argentina that disembarked its passengers and crew in the Canary Islands on May 10. At least three people on board the MV Hondius died and several cases were reported as serious.
Moderna is the Cambridge, Massachusetts-based biotechnology company that perfected messenger RNA (mRNA) vaccines during the Covid-19 pandemic. Following news that Moderna was developing a hantavirus vaccine using the same technology, the drugmaker’s stock rose from $49 on May 7 to $55 the next day. But it’s important to note that Moderna did not begin work on vaccination following the MV outbreak. Hondius. In fact, the drugmaker has undertaken this collaboration project with VIC-K in 2023.
The fight for a vaccine
The outbreak of hantavirus on the high seas has been one of the major international events of recent weeks, meaning that many people around the world are only just learning about this virus, but it is not a newcomer. In fact, hantavirus has been a known pathogen for decades. Transmitted primarily by exposure to the feces, urine or saliva of infected rodents, it can cause hemorrhagic fever with renal syndrome (prevalent in Asia or Europe) or hantavirus pulmonary syndrome (more common in the Americas). The wife of actor Gene Hackman may be one of the most well-known recent people to die from the latter disease, but it is far from an exceptional phenomenon. In total, hantaviruses cause around 50,000 serious, often fatal, infections worldwide each year. So-called New World hantaviruses, such as Andean hantavirus (ANDV), are found primarily in South America and can achieve a case fatality rate of up to 40 percent; ANDV is the only hantavirus with documented human-to-human transmission, and just the variant identified by the World Health Organization in MV. Hondius.
There is currently no vaccine to prevent ANDV infection, and the Spanish Society of Immunology points out that “there is no approved vaccine against hantavirus in Europe, the United States or Latin America.” Treatment strategies are oriented toward the virus life cycle, host immunological factors, or clinical symptom management.
South Korea is a partial exception to this picture. The country reports 300 to 400 cases a year, mostly among young men in their 20s and 30s, and the country’s health authorities have included the pathogen on their list of nine priority threats for future pandemic preparedness. A previous generation inactivated vaccine called Hantavax exists in Korea, but its limited effectiveness and production methodology (it is derived from animal brain tissue) keep it far from modern standards.
South Korea was the starting point for Moderna’s most advanced collaboration in this area. The biotechnology company and VIC-K signed a research and development agreement in September 2023 as part of the US company’s mRNA Access initiative, a program that provides preclinical mRNA vaccine candidates to academic teams working on emerging or neglected infectious diseases.
The mechanism of the collaboration works as follows: the Korean team provides the antigenic sequence information of the hantavirus and Moderna provides the corresponding mRNA material. The preliminary results of this first research are already available. In February 2025, Park Man-sung’s team from the Department of Microbiology confirmed that experimental doses prevented hantavirus infection in mice.
A vaccine that could take years to arrive
The distance between a mouse trial and a vaccine approved for humans is considerable, especially when there is no longer the sense of urgency of the pandemic or the government support of Operation Warp Speed. The vaccine candidate is still in the preclinical phase, meaning it has yet to begin human trials and faces significant financial and regulatory hurdles before that can happen.
Additionally, hantaviruses are diverse and exhibit regional variations. Designing a vaccine capable of protecting against multiple strains represents a complex task. It is precisely for this reason that this international collaboration aims to develop a broad-spectrum vaccination, effective against more variants than existing vaccines in Asia.
