Three viruses you need to watch out for in 2026

An expert has named three viruses that could pose a serious threat to humans in 2026.

These bugs could be “poised” to cause infections in “unexpected places or in unexpected numbers.”

Writing for The Conversation, Patrick Jackson - the assistant professor of infectious diseases at the University of Virginia, warned that the threat of widespread illnesses is consistently present.

He explained: “A new year might mean new viral threats. Old viruses are constantly evolving.”

Prof Jackson continued, "A warming and increasingly populated planet puts humans in contact with more and different viruses. And increased mobility means that viruses can rapidly travel across the globe along with their human hosts.”

“As an infectious diseases physician and researcher, I’ll be keeping an eye on a few viruses in 2026 that could be poised to cause infections in unexpected places or in unexpected numbers,” he added.

Influenza A:

It is one of the four known types of influenza, or flu. Viruses from influenza A are the only kind of influenza known to lead to pandemics.

Mpox:

Prof Jackson said mpox is “worldwide and liable to worsen.” Formerly known as monkeypox, the virus actually mostly infects rodents and occasionally crosses over into humans.

“Mpox is closely related to smallpox, and infection results in a fever and painful rash that can last for weeks,” he said, adding, “There are several varieties of mpox, including a generally more severe clade I and a milder clade II.”

A vaccine for mpox is available, but there are currently no effective treatments.

Oropouche virus:

This is an insect-borne virus and, according to Prof Jackson, is “poised to spread,” carried by mosquitoes and small biting midges.

Prof Jackson said: “Most people with the virus experience fever, headache and muscle aches. The illness usually lasts just a few days, but some patients have weakness that can persist for weeks. The illness can also recur after someone has initially recovered.”