Viral outbreaks to watch in 2026 include influenza A, mpox and Oropouche

An infectious disease expert highlights influenza A, mpox and Oropouche as viruses to watch in 2026, noting viral evolution, changing human–animal contact and global travel as key drivers.

An infectious diseases physician and researcher lists several viruses to watch in 2026 and explains why they merit attention. The author notes that viruses evolve continuously and that climate change, population growth and international travel increase opportunities for spread. The article highlights influenza A (including concerns about H5N1), mpox and Oropouche virus. It also mentions other risks such as chikungunya, rising measles cases and pressures on HIV control. Key points: - Influenza A: Highly pathogenic avian influenza H5N1 has been detected beyond birds, including in U.S. dairy cattle in 2024, and researchers are monitoring for any changes that would allow sustained human-to-human transmission; current seasonal influenza vaccines likely offer limited protection against H5N1 while targeted vaccines are in development. - Mpox: Clade II mpox became established globally after the 2022 outbreak, and increases in clade I cases have been reported in parts of central Africa since 2024; a small number of clade I cases were reported in the U.S. since August 2025, including in people without recent travel. - Oropouche virus: Carried by biting midges and mosquitoes, it was long confined to the Amazon region but has expanded across parts of South and Central America and the Caribbean; the vector exists in much of the Americas, and there are no specific treatments or vaccines. Summary: These developments mean scientists will continue surveillance and research to detect changes in virus behavior and to develop countermeasures. The potential impact varies by virus and region. Undetermined at this time.