Viruses are a constant threat, and those who study them remain vigilant. As 2026 progresses, health specialists are facing a complex viral landscape that demands attention. This is a crucial reminder that the pandemic era isn’t over, and ongoing monitoring is essential for protecting public health.
According to a recent article published in The Conversation, Patrick Jackson, an adjunct professor of Infectious Diseases at the University of Virginia, has identified three viruses that warrant particular focus this year: avian influenza H5N1, mpox, and the lesser-known Oropouche virus.
While distinct from one another, these viruses share a concerning characteristic: they have expanded their reach into new territories and are potentially poised for further spread. This doesn’t necessarily signal alarm, but rather highlights the need for strategic surveillance of real and emerging threats.
Oropouche Virus: An Emerging Threat Spreading from the Amazon
The Oropouche virus is perhaps the least familiar of the three, but it’s receiving increasing attention from scientists. Transmitted by tiny mosquitoes, it causes symptoms similar to the flu. First identified in Trinidad in the 1950s, it was long considered limited to the Amazon region, but since the 2000s, it has been expanding across South and Central America, and the Caribbean.
In 2024, Brazil documented the first deaths associated with the virus, and cases linked to travelers were reported in Europe, according to IFL Science. Instances of vertical transmission – from mother to child – were detected, and a possible connection to cases of microcephaly is being investigated.
This is particularly concerning because the transmitting insect has already adapted to wide areas of the continent and is also present in southeastern regions of the United States. Currently, there are no specific vaccines or treatments available.
In response, the World Health Organization (WHO) presented a roadmap on January 5, 2026, to accelerate the development of prevention and control tools against Oropouche, as reported by IFL Science.
Avian Influenza H5N1: From Poultry to People
Influenza A has historically posed a constant threat due to its rapid mutation rate and ability to infect various species. The 2009 H1N1 pandemic, for example, caused more than 280,000 deaths in its first year, according to The Conversation. Understanding the evolution of influenza viruses is critical for pandemic preparedness.
Now, attention is focused on H5N1, commonly known as avian influenza. This virus moved beyond affecting only birds in 2024, when it was first detected in dairy cows in the United States. This species jump raised concerns among experts, as the detection wasn’t isolated; the virus began reappearing in herds across multiple states. Studies suggest numerous transmissions from cows to humans have already occurred, often without noticeable symptoms, Jackson noted.
The primary fear is that the virus will achieve what it hasn’t yet: adapt to transmit effectively between people. This would be a necessary step for a new pandemic to emerge.
Currently, the Centers for Disease Control and Prevention (CDC) has reported 71 human cases and two deaths since 2024, and there is no evidence of sustained community transmission. However, specific vaccines are already under development, as current formulations likely wouldn’t provide sufficient protection against this strain.
Mpox: Two Variants in Global Circulation
For decades, mpox – previously known as monkeypox – was a rare disease largely confined to certain regions of Africa. That changed in 2022, when a global outbreak of Clade IIb spread to over one hundred countries. The transmission through close physical contact, often during sexual activity, marked a turning point, transforming this variant from a localized phenomenon into a virus circulating recurrently worldwide.
However, a parallel and concerning trend is emerging: since 2024, countries in Central Africa have reported increases in infections from Clade I, considered more severe. Even the United States has recently reported cases of Clade Ib in individuals with no history of travel to Africa. While a vaccine exists, there is currently no specific treatment, and experts warn that the virus’s evolution throughout 2026 could present new public health challenges.
Measles, Chikungunya, and Other Viral Threats in 2026
Beyond these three primary concerns, other viruses are also beginning to raise alarms. Chikungunya, for example, caused more than 445,000 suspected and confirmed cases in 2025, with at least 155 reported deaths as of September, according to IFL Science.
The Nipah virus is also back under surveillance following a recent outbreak in West Bengal, whereas specialists emphasize that it currently doesn’t demonstrate the capacity to cause a pandemic.
And then there are the familiar foes, those many believed were already under control. Measles, for instance, has resurfaced in various countries due to declining vaccination rates, even jeopardizing elimination status in places like the United States.
Some experts also caution that diseases like HIV could see a resurgence if cuts continue to international health cooperation programs.
All of this serves as a reminder that the feeling that the COVID-19 pandemic was an exceptional and fully overcome episode may be premature. The lessons learned during the pandemic underscore the importance of continued vigilance and investment in public health infrastructure.
The lesson, for now, seems clear: in a world where ecosystems are changing and human mobility facilitates the circulation of pathogens, constant surveillance and preparedness remain key tools for preventing local outbreaks from becoming global crises.
