Pandemic predictions 2026: what counts as one, will there be another, and hantavirus

An outbreak, an epidemic, and a pandemic describe the same health threat at three distinct geographical scales, but only some of these terms carry formal legal weight. The World Health Organization (WHO) manages global health crises through an international treaty called the International Health Regulations (IHR). Under this framework, WHO's formal emergency alert is a Public Health Emergency of International Concern, abbreviated as a PHEIC.

Institutional language dictates how global health authorities respond to emerging threats. Formal declarations operate under strict legal criteria outlined by international treaties, while terms like "pandemic" are often used as descriptions of geographic reach rather than statutory triggers. Because specific legal tiers carry distinct thresholds for global coordination and resource allocation, a disease can trigger an international emergency declaration without officially being characterized as a pandemic.

What is a pandemic?

A pandemic is an epidemic that has spread across several countries or continents, usually affecting a large number of people, which is the official definition taught by the U.S. Centers for Disease Control and Prevention (CDC). An epidemic is a narrower event, defined as a surge in disease cases above normal expectations within a single population or region. The distinction between an epidemic and a pandemic is geographic reach, not clinical severity.

Formally declaring a pandemic involves specific institutional tiers. The WHO Director-General determines a PHEIC under the IHR, and amendments implemented on September 19, 2025, established a higher "pandemic emergency" tier for PHEIC events that escalate further. Historically, the standalone word "pandemic" has sat outside these strict legal triggers; for example, WHO characterized COVID-19 as a pandemic during a press briefing on March 11, 2020, rather than through a formal treaty mechanism.

This distinction shapes how global outbreaks are evaluated. Public health bodies may issue an emergency declaration based on rapid cross-border spread while withholding a formal pandemic designation if specific criteria are not met. When WHO declared an Ebola PHEIC on May 17, 2026, the agency explicitly noted in its announcement that the outbreak did not meet the criteria for a pandemic emergency.

Will there be another pandemic?

Historical data indicates that another pandemic will occur eventually, though epidemiological models cannot predict a specific year. WHO has declared nine Public Health Emergencies of International Concern since the modern IHR framework took effect in 2005. Out of those nine emergencies, only two were formally identified as pandemics at the time: H1N1 influenza in 2009 (under a previous six-phase alert framework) and COVID-19 in 2020.

Historical records show that global health emergencies arrive in unpredictable clusters rather than regular intervals. Among the nine declared PHEICs, three involved Ebola and two involved mpox, meaning historical averages cannot reliably predict when the next major outbreak will occur.

Evaluating future risks requires tracking both novel pathogens and known threats with epidemic potential. Health monitoring systems continuously evaluate whether expanding transmission chains in viral families like influenza, hantavirus, or novel coronaviruses could escalate into broader regional or global threats.

Will hantavirus become a pandemic?

Hantavirus is extremely unlikely to cause a global pandemic because the virus lacks sustained human-to-human transmission. According to the CDC, most hantavirus strains are not transmitted between people, and the strains native to North America are not known to spread from person to person at all. Hantaviruses are carried by rodents, with human infection typically occurring when individuals inhale airborne particles contaminated with rodent urine, droppings, or saliva.

Only one strain has demonstrated person-to-person transmission: Andes virus, found in Argentina and Chile. Following a documented Andes virus cluster on a cruise ship in early 2026, WHO evaluated the global risk as low and officially declared the outbreak resolved on July 2, 2026. While widespread human transmission remains rare, the disease is clinically severe, with the CDC reporting a fatality rate of nearly 40 percent for hantavirus pulmonary syndrome.

For hantavirus to pose a true pandemic threat, it would need to develop sustained human transmission chains, whereas documented Andes virus transmission chains have remained short and localized. Because the family remains a public health focus, WHO's 2024 pathogen prioritization list rates hantaviruses high for research preparedness. Global surveillance systems continue tracking hantavirus activity to detect any unusual mutations or transmission patterns early.

Modern pandemics and outbreaks.

• 2003, SARS: Caused 8,096 probable cases and 774 deaths across 29 countries before being successfully contained within months.
• 2009, H1N1 influenza: WHO raised its global alert level to pandemic phase 6 on June 11, 2009.
• 2012, MERS: First identified in Saudi Arabia, MERS caused localized outbreaks but was never characterized as a pandemic.
• 2014, Ebola in West Africa: Declared a PHEIC on August 8, 2014, becoming the largest Ebola outbreak in recorded history.
• 2016, Zika virus: Declared a PHEIC on February 1, 2016, with the emergency phase officially ending on November 18, 2016.
• 2020, COVID-19: Characterized as a pandemic on March 11, 2020, with the PHEIC status remaining active until May 5, 2023.
• 2022, Mpox: Declared a PHEIC on July 23, 2022, followed by a second mpox emergency declaration on August 14, 2024.
• 2026, Ebola in DR Congo and Uganda: Declared a PHEIC on May 17, 2026, which WHO noted did not meet the criteria for a formal pandemic emergency.

Frequently asked questions.