A recent outbreak of hantavirus on a cruise ship has highlighted a critical gap in global health preparedness: despite decades of knowledge, no approved treatments or vaccines exist for this deadly rodent-borne virus. Researchers in Chile, Argentina, and the United States have long pursued interventions, but the virus's rarity and limited human-to-human transmission have historically deterred sustained investment from governments and pharmaceutical companies.
Now, promising developments are emerging. A study published in The Lancet Infectious Diseases reports that tocilizumab, a drug typically used for rheumatoid arthritis, may help hantavirus patients combat severe symptoms. In a compassionate-use study in Argentina, four of five patients who received the drug survived, while five eligible patients who did not receive it died. The researchers caution that the untreated patients were sicker and older, but say the drug warrants further investigation.
Another approach involves cloned antibodies from hantavirus survivors. A team led by virologist María Inés Barría of Universidad San Sebastián in Chile, including scientists from the U.S. National Institutes of Health and the Robert Koch Institute, showed the method worked in animals in 2018 but could not secure funding for human trials, partly due to resources diverted to the COVID-19 pandemic.
Experts hope the cruise ship outbreak and concerns that climate change may increase human-rodent contact will galvanise new momentum. Dr. Fernando Tortosa of the National University of Río Negro in Argentina, lead author of the tocilizumab study, said: 'I hope this situation will help us continue our research and strengthen collaboration.'
Hantavirus infections are rare but often deadly: in the U.S., 35% of cases since 1993 have been fatal. The Andes virus, responsible for the cruise ship outbreak, is the only hantavirus thought to spread between people in some cases. Three of 13 likely cases on the cruise ship ended in death, while Chile has reported 15 deaths and 42 cases this year, and Argentina 32 deaths and 102 cases since June 2025.
