In a study published in lancetUniversity of Texas Medical Branch (UTMB) researchers report the development of a new vaccine that provided complete protection against the deadly Andean hantavirus after a single dose in animal studies.
Dr. Alexander Boukreev, director of UTMB’s Viral Pathogenesis and Vaccine Development Laboratory, said UTMB, with support from the National Institutes of Health, is working to quickly introduce these single-dose vaccines into human clinical trials.
Hantavirus first came to the public’s attention in May after an outbreak aboard the Dutch cruise ship MV Hondius, which departed from Argentina. The infection spread among passengers and crew members at sea, resulting in 13 infections and three deaths.
Andes virus belongs to the Hantaviridae family, but unlike other viruses, it can be transmitted directly from person to person through coughing or close contact. Other hantaviruses are usually spread through contact with infected rodents, making Andes virus a more significant public health threat.
The cruise passengers then returned to their home countries and are scattered across 23 countries. Because people can carry the virus for weeks before showing symptoms, health authorities face a complex challenge in identifying all infected people before they unknowingly infect others.
Using mRNA technology, Boukreev and his team, including vaccine co-designer Dr. Ivan V. Kuzmin, had previously created a version that had successfully protected animals using a two-dose regimen. Recognizing that the rapidly evolving international epidemic does not allow patients to wait weeks between shots, the team retested the vaccine to determine if a single dose is effective.
The results exceeded expectations. When testing the vaccine in animal models that mimic the human disease, scientists found that a single dose provided 100% protection against a lethal dose of the virus. Even when the researchers significantly reduced the dose to a fraction of the original amount, the results remained conclusive.
All vaccinated animals were completely healthy and showed no symptoms or weight loss. When the tissues of vaccinated animals were observed one month after infection, the virus had completely disappeared. The vaccine elicits a strong immune response and produces protective antibodies in just 14 days. ”
Dr. Michelle Meyer, first author
Because the Andes virus takes a relatively long time to cause severe disease in humans, these fast-acting vaccines could serve a dual purpose, acting as an emergency tool for people already infected.
“If administered quickly to high-risk contacts during an outbreak, such as the Andean virus outbreak on a cruise ship, it could theoretically activate the immune system quickly enough to stop the virus, stopping it from replicating and preventing them from getting sick and further spreading,” Boukreev said.
sauce:
University of Texas at Galveston School of Medicine
Reference magazines:
Mayer, M. others. (2026). Single-dose mRNA vaccine against Andean hantavirus. lancet. DOI: 10.1016/s0140-6736(26)01124-4. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(26)01124-4/fulltext
