Recent news reports about the Andes strain of hantavirus have raised new questions about this rare but serious virus spread by rodents. Health officials around the world are currently monitoring a multi-country outbreak linked to a cruise ship traveling from South America after several confirmed infections and deaths were reported.
As of May 2026, health officials have confirmed multiple Andes hantavirus cases across several countries connected to the ongoing cruise ship outbreak, with international monitoring and contact tracing efforts continuing. Health officials have also stated there is currently no confirmed evidence that the Andes strain involved in the outbreak has changed in a way that would make it spread more easily between people.
The situation has drawn global attention because the Andes strain is different from most hantaviruses: it is the strain most strongly linked to documented person-to-person transmission.
While public health experts continue monitoring the outbreak carefully, organizations including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) currently state that the overall public risk remains low.
At Suburban Research Associates we believe education and clinical research play an important role in helping communities better understand emerging infectious diseases and how researchers prepare for future public health threats.
What Is Hantavirus?
Hantaviruses are a family of viruses primarily carried by rodents. In humans, certain strains can cause serious illnesses, including Hantavirus Pulmonary Syndrome (HPS), a rare but potentially severe respiratory disease.
Hantavirus first gained major attention in the United States in 1993 after an outbreak in the Four Corners region, where Arizona, Colorado, New Mexico, and Utah meet. Since national surveillance began, approximately 890 confirmed U.S. cases have been reported, making it uncommon—but still important to monitor.
Globally, different strains of hantavirus exist in Asia, Europe, and the Americas, with some forms affecting the lungs and others impacting the kidneys.
Because hantavirus can spread from animals to humans, researchers continue studying how different strains behave and how outbreaks can be prevented.
What Are the Symptoms of Hantavirus?
Early hantavirus symptoms may resemble the flu and can include:
- Fever
- Fatigue
- Muscle aches
- Headaches
- Chills
- Nausea or dizziness
In more severe cases, symptoms may progress to coughing and difficulty breathing, particularly in cases involving Hantavirus Pulmonary Syndrome (HPS).
Anyone experiencing severe respiratory symptoms after potential rodent exposure should seek medical attention promptly.
What Is the Andes Strain of Hantavirus?
The Andes strain, also called Andes virus or Andes orthohantavirus, was first identified in South America in the 1990s and is most commonly associated with Argentina and Chile.
Unlike most hantaviruses, the Andes strain has demonstrated limited person-to-person transmission in some previous outbreaks involving close and prolonged contact.
Health officials are currently monitoring a 2026 outbreak linked to the cruise ship MV Hondius, where several passengers developed severe respiratory illness after traveling through parts of South America. WHO reports indicate that confirmed and suspected cases linked to the outbreak have been identified across multiple countries.
Investigators believe some infections may have originated before passengers boarded the ship, potentially through environmental exposure in affected areas of South America.
How Does Hantavirus Spread?
Most hantaviruses spread through exposure to infected rodents and contaminated environments rather than routine human contact.
People may become exposed when:
- Cleaning garages, sheds, cabins, or attics with rodent infestations
- Sweeping or vacuuming areas contaminated with rodent droppings
- Handling contaminated nesting materials
- Spending time in heavily infested rural or outdoor environments
Unlike COVID-19, most hantaviruses do not spread easily through person-to-person contact. However, limited transmission between close contacts has been documented with the Andes strain in certain outbreaks.
Researchers continue studying exactly how the Andes strain spreads between people and why it behaves differently from other hantaviruses.
Could Hantavirus Become Another Pandemic?
The current Andes hantavirus outbreak has understandably raised concerns because the virus has shown limited person-to-person transmission. However, health experts currently emphasize that this situation is very different from the early spread of COVID-19.
According to WHO, the overall global public health risk is currently considered low.
WHO officials have also stated that additional cases may still emerge because the Andes strain can have a relatively long incubation period, and many passengers interacted before the outbreak was identified. International monitoring and contact tracing efforts are continuing across multiple countries.
Several factors contribute to that assessment:
- Hantavirus infections remain rare
- Transmission appears far less efficient than COVID-19
- Most known spread involves close-contact exposure
- Public health agencies are actively monitoring contacts and cases
- Lessons learned during COVID-19 have improved outbreak response systems worldwide
WHO and international health officials are currently coordinating case isolation, contact tracing, testing, and travel monitoring connected to the outbreak.
Experts also note that today’s public health systems are significantly more prepared to identify and respond to emerging infectious diseases than they were before the COVID-19 pandemic.
Health officials have also stated there is currently no confirmed evidence that the Andes strain involved in the outbreak has mutated in a way that would make it spread more easily between people.
What Health Experts Are Monitoring
Public health officials are continuing to monitor:
- Whether additional person-to-person transmission occurs
- New confirmed cases linked to exposed travelers and close contacts
- How long the incubation period may last in exposed individuals
- Whether the virus shows evidence of changes in transmission patterns
Researchers are also continuing to study why the Andes strain behaves differently from most other hantaviruses.
Why Vaccine Clinical Trials Matter for Hantavirus
Although the current public risk remains low, the outbreak has highlighted why ongoing infectious disease research and vaccine preparedness remain important.
Even when diseases are rare, vaccine clinical trials remain one of the most important tools for helping scientists prepare for future outbreaks.
At this time, there is no FDA-approved hantavirus vaccine available in the United States, though researchers around the world continue studying investigational vaccine approaches.
Andes Virus DNA Vaccine Research
One promising area of research involves an investigational Andes virus DNA vaccine. In a Phase 1 clinical trial tied to study NCT03682107, researchers evaluated a DNA vaccine candidate targeting the Andes strain of hantavirus using the PharmaJet Stratis needle-free injection system.
Researchers reported that the investigational vaccine was generally well tolerated and produced measurable immune responses in healthy adult participants. Phase 1 clinical trials are designed primarily to evaluate safety and immune response in small groups of healthy volunteers. While additional research is still needed, early-stage clinical trial results like these help scientists better understand whether a vaccine candidate may be appropriate for larger studies in the future.
Researchers have also studied investigational DNA vaccines targeting additional hantavirus strains, including Hantaan virus (HTNV) and Puumala virus (PUUV), which are associated with hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe.
In published Phase 1 clinical trial data, researchers reported these vaccine candidates were generally well tolerated and capable of producing immune responses in study participants when delivered using the PharmaJet Stratis needle-free injection system.
While these investigational vaccines are still in the early stages of research and are not approved for public use, studies like these help researchers better understand how different vaccine platforms may potentially support future infectious disease preparedness efforts.
Emerging Vaccine Technologies
Researchers are also exploring whether newer vaccine technologies, including mRNA platforms, may help accelerate vaccine development for emerging infectious diseases in the future.
Moderna has publicly discussed early hantavirus-related research efforts connected to mRNA technology, though this work remains in early-stage development and has not advanced to publicly available late-stage clinical trials.
Novavax has also been mentioned in broader discussions about infectious disease vaccine technology because of its protein-based vaccine platform and Matrix-M adjuvant expertise. However, there are currently no publicly confirmed late-stage clinical trials involving a Novavax hantavirus vaccine candidate.
Together, these efforts highlight how vaccine clinical trials and ongoing infectious disease research may help scientists better understand emerging viruses and improve future outbreak preparedness strategies.
Lessons Learned From COVID-19 Vaccine Research
The COVID-19 pandemic demonstrated how important vaccine clinical trials are during emerging public health situations. Clinical trials helped researchers rapidly collect scientific data needed to evaluate vaccine safety, effectiveness, dosing, and immune response across large and diverse populations.
COVID-19 vaccine clinical trials also helped scientists and public health agencies:
- Better understand how respiratory viruses spread
- Improve outbreak response systems and global collaboration
- Advance vaccine technologies such as mRNA platforms
- Develop faster methods for identifying and monitoring new variants
- Build stronger infrastructure for future infectious disease research
Many of the systems built during the COVID-19 pandemic are now helping researchers respond more quickly to other emerging infectious diseases, including hantavirus and other zoonotic viruses.
Clinical research also supports the development of testing methods, antiviral therapies, and public health response plans that may help communities respond more effectively to future infectious disease threats.
Infectious disease clinical trials also help researchers better understand how viruses spread, how long symptoms may take to appear, and how public health systems can respond more quickly during outbreaks.
While not every emerging virus leads to a global pandemic, continued vaccine research remains an important part of global infectious disease preparedness.
People interested in learning more about clinical research participation can explore educational resources and ongoing research opportunities through Suburban Research Associates.
Tips to Help Reduce the Risk of Hantavirus Exposure
Although hantavirus infections remain rare, health experts recommend taking practical precautions in areas where rodents may be present, especially when cleaning enclosed or rarely used spaces.
1. Use Caution When Cleaning Areas With Rodent Activity
Avoid sweeping or vacuuming rodent droppings or nesting materials, as this may push particles into the air. Instead, health officials recommend using disinfectant and disposable gloves when cleaning affected areas.
2. Help Prevent Rodents From Entering Living Spaces
Sealing holes or gaps around homes, garages, sheds, and cabins may help reduce rodent activity indoors.
3. Store Food Securely
Keeping food, pet food, and trash in sealed containers may help avoid attracting rodents.
4. Be Extra Careful in Rarely Used Indoor Spaces
Cabins, sheds, attics, barns, and storage areas that have been closed for long periods may be more likely to have rodent activity.
5. Follow Public Health Guidance During Known Outbreaks
During active outbreaks, health officials may recommend monitoring symptoms, limiting close contact with infected individuals, or following travel-related guidance in affected areas.
6. Practice Good Hygiene
Regular handwashing and cleaning contaminated surfaces are good habits that may help reduce exposure to infectious diseases.
Frequently Asked Questions About Hantavirus
Is hantavirus contagious
Most hantaviruses are not spread through person-to-person transmission. However, the Andes strain has shown limited person-to-person spread in some close-contact settings.
Can hantavirus spread between people?
Most hantavirus infections occur through exposure to infected rodents or contaminated environments. Limited person-to-person transmission has been documented with the Andes strain in certain outbreaks involving close contact.
Is there a vaccine for hantavirus?
There is currently no FDA-approved hantavirus vaccine available in the United States, though researchers continue studying investigational vaccine approaches.
How many hantavirus cases have been reported in the United States
Hantavirus infections are considered rare in the United States, with approximately 890 confirmed cases reported since national surveillance began in 1993.
What are early symptoms of hantavirus?
Early symptoms may include fever, fatigue, muscle aches, headaches, chills, nausea, and dizziness. In severe cases, symptoms can progress quickly and affect breathing.
How does hantavirus spread?
Most hantavirus infections occur through exposure to infected rodents, rodent droppings, urine, saliva, or contaminated environments.
The Importance of Ongoing Clinical Research
Emerging infectious diseases have long been part of global public health challenges, and continued research remains important for helping scientists better understand viruses and prepare for future outbreaks.
As part of the Atlas Clinical Research network, Suburban Research Associates believes continued investment in infectious disease clinical research plays an important role in helping researchers improve outbreak preparedness, evaluate potential treatments and vaccines, and advance public health knowledge.
Dr. Matthew Davis, Medical Director and Principal Investigator at fellow Atlas Clinical Research network site Rochester Clinical Research, said, “The current hantavirus outbreak is a reminder that emerging infectious diseases are not theoretical threats — and that sustained clinical research is essential for developing the diagnostics, treatments, and preparedness strategies needed before the next outbreak occurs.”
Clinical research continues to play an important role in helping researchers better understand emerging viruses and prepare for future public health challenges.
Sources
World Health Organization (WHO) – Disease Outbreak News – https://www.who.int/emergencies/disease-outbreak-news
Centers for Disease Control and Prevention (CDC) – About Hantavirus – https://www.cdc.gov/hantavirus/about/index.html
CDC – Hantavirus Prevention – https://www.cdc.gov/hantavirus/prevention/index.html
CDC – Andes Virus Information – https://www.cdc.gov/hantavirus/about/andesvirus.html
National Institutes of Health (NIH) – Hantavirus Research – https://pmc.ncbi.nlm.nih.gov/articles/PMC7002362
NIH/PMC – Phase 1 Andes Virus DNA Vaccine Trial (NCT03682107) – https://pmc.ncbi.nlm.nih.gov/articles/PMC10786244/
ClinicalTrials.gov – NCT03682107 – https://clinicaltrials.gov/study/NCT03682107
NIH/PMC Phase 1 clinical trial of Hantaan and Puumala virus DNA vaccines delivered by needle-free injection – https://pmc.ncbi.nlm.nih.gov/articles/PMC11570633
Safety and Immunogenicity of an Andes Virus DNA Vaccine by Needle-Free Injection: A Randomized, Controlled Phase 1 Study – https://academic.oup.com/jid/article/229/1/30/7209758
