A recent outbreak of hantavirus has highlighted the challenges posed by this rare but often fatal disease, as well as the limited treatment options available. At least three passengers aboard the cruise ship MV Hondius have died from the infection, with an additional eight confirmed cases. Health officials expect the number of infected individuals to increase, due to the virus’s incubation period of up to six weeks.

Hantavirus is typically transmitted through contact with rodent droppings and carries a fatality rate of approximately 38%. The strain responsible for the current outbreak is the Andes virus, notable for its capacity to spread from person to person, unlike most other hantavirus variants. Despite the severity of the illness, there are currently no approved vaccines or specific treatments for hantavirus infections.

Research efforts have shown promise in developing effective countermeasures, but progress has been slow. An international team of scientists reported in 2022 that an antibody they developed conferred protection against the Andes strain in laboratory hamsters. Additionally, a small clinical trial conducted in 2024 by the U.S. Army Medical Research Institute of Infectious Diseases demonstrated that a DNA vaccine induced the production of neutralizing antibodies in over 80% of participants tested against the Andes virus.

Moderna, the biotechnology company known for its COVID-19 mRNA vaccine, has also engaged in early-stage research to create a hantavirus vaccine. However, experts say the development and approval of these new vaccines and treatments have been hampered by insufficient funding and low commercial demand, as hantavirus cases globally number only about 10,000 annually.

Immunologist Tony Schountz noted that while several promising vaccine candidates exist, the financial resources needed to advance them through later stages of development—estimated to cost between $25 million and $50 million—are not currently available. Without a substantial increase in investment, experts warn that the medical community will continue to face limited options in combating future hantavirus outbreaks.