An infectious disease expert at the University of Virginia identifies three viruses that could cause more problems in 2026: influenza A, mpox and the Oropouche virus (among others).
In a warmer, more populated and more globalized world, viruses circulate more easily and adapt quickly. An infectious disease expert identifies three viral agents that could cause infections “in unexpected places or in unexpected numbers” as early as 2026.
Viruses are always constantly mutating and evolving, but current world conditions accelerate the risks: global warming alters the distribution of disease-carrying animals and insects; population growth increases contact between humans and virus-carrying species and the allows an infectious agent to cross continents in a few hours.
It is in this context that Patrick Jackson, assistant professor of Infectious Diseases at the University of Virginia, in the USA, writes in the online publication which is particularly attentive to some viruses that could gain expression in 2026.
Influenza A: The Permanent Risk of Pandemic
The influenza A virus – which causes – is a constant threat. The virus infects several animal species and undergoes frequent mutations, which facilitates the emergence of new variants.
The influenza pandemic, caused by subtype H1N1 em 2009, caused more than 280 thousand deaths in the first year worldwide. The virus continues to circulate – it is also known as swine flu because it originated in pigs in Mexico.
More recently, attention has focused on the subtype H5N1, a bird flu.
First identified in humans in southern China in 1997, the virus has spread globally through wild birds. In 2024 it was detected for the first time in dairy cattle in the United States.
This transition from birds to mammals increased the scientific community’s concern about the virus’s adaptation to humans.
There are already studies that demonstrate that there have been several transmissions from cows to humans and the fear is transmission between people, an essential condition for the start of a new pandemic.
The flu vaccines that are currently available do not offer protection against H5N1, but specific vaccines are being developed.
Mpox: an already global virus
O was identified in the 1950s and for decades was mainly limited to sub-Saharan Africa. Despite its original name, the virus It mainly infects rodents and can occasionally be transmitted to humans.
The virus causes fever and painful rashes that can last for weeks. There are two large genetic groups: clade I, generally more severe, and clade II, milder.
By 2022, a global clade II outbreak had spread to more than 100 countries, including many where the virus had never been detected. Transmission occurred mainly through close contact, often in the context of sexual intercourse.
Although cases have since declined, mpox has become established in several countries. Since 2024, there has been an increase in clade I cases in Central African countries. In the United States, four cases of this clade have been confirmed since August 2025, including in people with no history of travel to Africa.
Oropouche virus: transmitted by insects
The Oropouche virus was first identified in the 1950s on the island of Trinidad, off the coast of South America. It is transmitted by mosquitoes and small biting insects, known as maruins.
The infection causes fever, headaches and muscle pain. Most cases resolve within a few days, but some patients experience prolonged weakness and the disease may recur after initial improvement. THEOccasionally, there are infections that develop more serious neurological symptoms and can cause diseases such as meningitis or encephalitis.
O (ECDC) emphasizes, however, that these cases are “extremely rare.”
For decades it was thought to be restricted to the Amazon region. Starting in the 2000s, cases began to emerge in other areas of South America, Central America and the Caribbean. In the United States, cases have occurred mainly in travelers returning from these regions.
The transmitting mosquito is present in much of North and South Americaincluding the North American southeast, which could facilitate the geographic expansion of the virus.
There are no vaccines or specific treatments.
Other threats on the horizon
Patrick Jackson also warns of other risks in 2026:
- ongoing global outbreaks of the virus – some countries already have a vaccine available.
- increase in cases of associated with decreased vaccination rates;
- possible resurgence of because, despite the existence of effective treatments, they do not reach parts of the world that depend on international aid, which has since been suspended.
- as-yet-unknown viruses that may emerge as ecosystems are disturbed.
The expert emphasizes that people, animals and the environment are interconnected. Epidemiological surveillance and the development of new vaccines and therapeutics will be decisive in reducing the risk of future health crises.
