A Facebook post suggests that the hantavirus was engineered after sharing a screenshot of a Hantavirus vaccine patent filed in 2022. The post claims hantavirus ‘arrived’ in 2026, four years after a vaccine patent was filed in 2022, implying a coordinated release designed to push vaccine uptake.
This post was made by Iris Koh, a prominent anti-vaccine figure in Singapore. Koh has a documented history of spreading misleading information about COVID-19 and vaccines which led to YouTube removing content from her channel, and Facebook suspending her account on multiple occasions. She was also charged in 2022 with conspiring to cheat the Ministry of Health that people were vaccinated against COVID-19 when they were not.
In her post, Koh implies that the hantavirus is following “the playbook of Covid”, a strategy she describes as: engineer a virus, create the vaccine solution, spread fear and propaganda, then use that fear to coerce vaccination by restricting access to public spaces and employment. Koh suggests hantavirus is the next iteration of this alleged strategy.
The virus has captured headlines around the world following reports of a cluster of cases aboard the cruise ship MV Hondius, which was travelling from Argentina to Cape Verde. According to the World Health Organisation, nine cases and three deaths have been confirmed among passengers and crew so far. As of 13 May 2026, Singapore’s Communicable Diseases Agency (CDA) has isolated two Singaporeans who were aboard MV Hondius at the National Centre for Infectious Diseases, prompting public concern locally.
While the Facebook post itself has, to date, received limited engagement, it was also circulated on the Telegram channel, “Healing the Divide”, with thousands of members, increasing its potential reach. Closed platforms like Telegram also enable misinformation and disinformation to spread without public visibility or scrutiny. Given the heightened concern around the hantavirus, we decided to take a closer look at Koh’s claims.
What is the hantavirus?
Hantavirus refers to a group of zoonotic viruses, meaning they originate in animals, primarily rodents, but can sometimes infect humans. People are typically infected through contact with infected rodents, their urine, droppings, saliva, or contaminated environments. Human infections can be severe and, in some cases, fatal, with the severity depending on the specific hantavirus strain and geographic region. The strain linked to the MV Hondius outbreak is the Andes virus, found in parts of South America, which is one of the rare hantavirus strains capable of human-to-human transmission.
Hantavirus is not new. The virus has been documented as early as the late 1970s, contradicting Koh’s suggestion that the virus was recently discovered. Multiple cases have been reported in Singapore, including one published in Annals, the official medical journal of the Academy of Medicine, Singapore, in 2024. More significantly, in 2018, the Andes strain of hantavirus spread through a village in Argentina, infecting 34 peopleand causing 11 deaths. This 2018 outbreak shows the virus was already circulating in human populations four years before the patent referenced in Koh’s post was filed in 2022.
Research into hantavirus vaccines and treatments has been ongoing for years, just as scientists routinely study vaccines for influenza, coronaviruses, Ebola, and other infectious diseases with outbreak potential.
What is the patent being referenced?
The post links to a US patent application titled “mRNA Vaccines Against Hantavirus” (US20250127870A1), filed on 15 September 2022 by researchers affiliated with the University of Texas, U.S. and published on 24 April 2025. The publication date reflects when patent details became public, and as of now the patent has not yet been granted.
A vaccine patent would describe how researchers plan to respond to a virus, and this patent describes an experimental mRNA-based vaccine approach targeting hantaviruses. The proposed vaccine works by providing genetic instructions that allow the body to temporarily produce these harmless viral proteins on its own. This trains the immune system to recognise and respond to these proteins, so if exposed to the actual virus later, the body can fight it off faster.
At its heart, vaccine development is preventive. Scientists routinely study viruses with outbreak potential before large-scale transmission occurs, as part of standard outbreak preparedness. Multiple hantavirus vaccine patents have been filed by different researchers over time demonstrating sustained scientific interest in the virus.
Despite decades of hantavirus research, there are currently no widely approved vaccines and no specific antiviral treatments proven effective.
What Koh’s claim overlooks
Koh’s argument appears to rest on a simple timeline: patent filed in September 2022, outbreak in 2026, therefore the virus was engineered and intentionally released. However, hantavirus has been documented and circulating in human populations well before. The virus did not “arrive” after the patent; the patent was filed because the virus already existed.
Therefore, we rate the claim that hantavirus was engineered as false. The patent cited in Koh’s post does not show that the virus was engineered, it describes how researchers plan to respond to an existing pathogen.
Multiple hantavirus vaccine patent materials have been misrepresented online as evidence that naturally occurring hantaviruses are manmade. People with a history of spreading health misinformation and disinformation might continue to find new things to repackage as conspiracy. Hence, we should always take a step back and be careful of what we encounter and share online, especially during periods of heightened anxiety.
