Bird flu worse than COVID? Here’s the short answer—and the real story behind the warning

Short answer: It could be—if the virus evolves to spread easily between people. Right now, experts say the risk of a human pandemic is low, and the world is better prepared than in 2020. But a few recent signals explain why scientists aren’t sleeping on this.

The most striking piece of news first

In November 2025, Washington State confirmed the first known human case of H5N5 bird flu anywhere in the world. The patient—an older adult with underlying conditions—later died. Health officials stressed there was no sign of spread to others and that human infections remain rare, usually after close contact with infected animals or contaminated environments. Still, “first ever” is not a phrase epidemiologists use lightly. Washington DOH

That’s the backdrop for a stark message from France’s Institut Pasteur: if avian flu adapts to spread efficiently among humans, a pandemic “could be quite severe, potentially even more severe than the pandemic we experienced,” says Marie‑Anne Rameix‑Welti. Reuters

What’s true, what needs nuance, and what we don’t know

• Verified: Pasteur’s warning is real—and measured
  Rameix‑Welti, who directs France’s National Reference Center for Viruses of Respiratory Infections (including influenza and SARS‑CoV‑2), told Reuters the concern is conditional: the danger rises if the virus adapts for human‑to‑human transmission. Her exact title differs slightly from some reports but her role matches. Reuters, Institut Pasteur

• Verified: Most of us have little to no immunity to H5
  Seasonal flu antibodies don’t provide specific protection against H5N1/H5N5. CDC assesses population immunity to H5N1 as very low. CDC

• Verified, with context: Avian flu can kill healthy people—so can COVID
  Historically, documented H5N1 cases have a high case‑fatality rate and many occurred in children and young adults. COVID‑19 hit older adults and people with underlying conditions hardest, but it also caused severe illness and death in otherwise healthy people. Saying COVID “mainly affects risk groups” oversimplifies the reality. WHO archive

• Verified: Current pandemic risk is assessed as low
  The World Organisation for Animal Health (WOAH) and partners say the probability of a human pandemic right now remains very low, higher only for people with frequent exposure to infected animals. Reuters

• Verified: We are better prepared than in 2020
  Governments have vaccine candidates ready to scale (including contracted H5 supplies) and stockpiles of antivirals that still look effective against current strains in lab tests. Newer platforms like mRNA are in the preparedness pipeline, though not licensed for general use. Reuters, Barron’s

• Verified: The cost to birds has been staggering
  “Hundreds of millions” of birds have been culled globally to contain highly pathogenic avian influenza. FAO

• Verified: Human cases remain rare and sporadic
  Most infections trace back to direct animal exposure; sustained person‑to‑person spread has not been documented. Cumulatively, WHO lists 986 H5N1 cases and 473 deaths through July 1, 2025—high severity among detected cases, but very few infections overall. PAHO/WHO, WHO data

• Opinion, not consensus: “The next pandemic is as good as certain if the virus adapts”
  German virologist Alexander Kekulé has warned in those terms. It’s a pointed expert view, not a forecast shared by all agencies today. Bild

The tension at the heart of this story

• The scary part: H5 viruses have shown they can be deadly in humans. We lack broad immunity. In a worst‑case scenario—if the virus learns to jump efficiently between people—severe illness could hit all age groups, not just the elderly.

• The grounding reality: That scenario hasn’t happened. The best current read from WHO/FAO/WOAH and national agencies is “low risk” for the general public. And unlike early 2020, we have playbooks, vaccine seeds, and antiviral stockpiles ready to deploy.

Think of it like a wildfire season. Conditions can be dry (low population immunity), and there’s already smoke on the horizon (rare human cases, massive impact in animals). Fire crews have gear staged (vaccines, antivirals, surveillance). A catastrophic blaze is possible—but not inevitable—and preparedness can prevent small sparks from becoming an inferno.

Important corrections and clarifications

• Title nuance: Rameix‑Welti’s role is accurately described in substance, but her formal title is Director of France’s National Reference Center for Viruses of Respiratory Infections, not “head of the Pasteur Center” as some wordings suggest. Institut Pasteur

• COVID severity: The claim that COVID‑19 “mainly affects risk groups” needs balance. Risk was highest in older and medically vulnerable people, but healthy adults and children also suffered severe outcomes. WHO archive

What to watch next

• Signals of human‑to‑human spread: clusters without animal exposure would change the risk calculus fast.
• Antiviral susceptibility: lab testing remains favorable today, but viruses evolve.
• Vaccine match and manufacturing speed: governments have contracts and seed strains, but timelines matter in a surge.
• Mammal spillovers: infections in cows, seals, or other mammals can give the virus “practice” adapting to new hosts.

How we checked

• We verified the Pasteur interview and the “low risk” assessment via Reuters (Nov 27, 2025).
  Link: https://www.reuters.com/business/healthcare-pharmaceuticals/bird-flu-poses-risk-pandemic-worse-than-covid-frances-institut-pasteur-says-2025-11-27/

• We confirmed Rameix‑Welti’s role on the Institut Pasteur site.
  Link: https://research.pasteur.fr/fr/nrc/viruses-of-respiratory-infections-including-influenza-and-sars-cov-2/?utm_source=openai

• We checked population immunity and antiviral notes with CDC.
  Link: https://www.cdc.gov/cfa-qualitative-assessments/php/data-research/h5-risk-assessment.html?utm_source=openai

• We traced the H5N5 human case to Washington State DOH and follow‑up reports.
  Link: https://doh.wa.gov/newsroom/h5n5-avian-influenza-confirmed-grays-harbor-county-resident?utm_source=openai

• We corroborated human‑case rarity and severity via WHO/PAHO.
  Links: https://www.paho.org/en/news/25-11-2025-paho-avian-influenza-ah5n1-continues-circulation-americas?utm_source=openai
  https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON575?utm_source=openai

• We verified preparedness details (vaccines, contracts) with Reuters and industry reporting.
  Links: https://www.reuters.com/business/healthcare-pharmaceuticals/bird-flu-poses-risk-pandemic-worse-than-covid-frances-institut-pasteur-says-2025-11-27/
  https://www.barrons.com/articles/moderna-bird-flu-vaccine-funding-95fc109a?utm_source=openai

• We confirmed the scale of animal culls with FAO.
  Link: https://www.fao.org/newsroom/detail/the-spread-of-h5n1-highly-pathogenic-avian-influenza-calls-for-stepped-up-action—fao-says/?utm_source=openai

Bottom line

• Bold warning, true condition: A bird‑flu pandemic could be worse than COVID—if the virus gains easy human‑to‑human transmission.
• Current status: Human risk remains low; human cases are rare and linked mostly to animal contact.
• Preparedness: Vaccine candidates exist, antivirals likely work, and surveillance is stronger than in 2020.
• Stay alert, not alarmed: Watch for changes in transmission, not headlines alone. And remember, vigilance plus preparation can bend the story away from worst‑case scenarios.

Background note: Institut Pasteur helped develop and share early COVID‑19 PCR tests in January 2020—one reason their warnings carry weight. Pasteur

Key finding in one line: The threat is real but conditional; the risk today is low, and we’ve got tools—useful now if we keep our nerve and our eyes open.