It always starts quietly. Just a few cases, a couple of infected animals, and some scientists raising cautious concerns. Then suddenly, it spreads fast. Remember March 2020, when “lockdown” became part of everyday life? What if something similar is already happening again—and we just haven’t noticed yet?

The person sounding the alarm this time is David Quammen, the same writer who warned us before COVID-19.

David Quammen: The Man Who Saw It Coming

David Quammen isn’t a fortune teller, but his past predictions were spot on. In his book Spillover, written before the COVID-19 pandemic, he warned about zoonoses—diseases that jump from animals to humans. At the time, some thought he was being overly cautious. But the pandemic proved he had a point.

Now, he’s focused on another virus: H5N1, better known as bird flu. It’s not new, but recent changes in the virus and how quickly it’s spreading have scientists worried.

Bird Flu Is Already Spreading in Animals

This isn’t just a “what if” situation anymore. In April 2025, H5N1 was found in a sheep in the UK—something that had never happened there before. Over in the U.S., things are even more serious. The virus has hit over 1,000 dairy farms, led to the culling of more than 168 million birds, and infected at least 70 people. One person has died.

This isn’t a plot from a movie—this is real. The virus is spreading not just in birds, but in mammals too, which makes it more likely to jump to humans.

The mechanics of pandemics: one mutation is enough

Quammen explains how viruses like this work. Every infected bird carries billions of copies of the virus. Each time the virus copies itself, there’s a small chance it mutates. Eventually, one of those mutations could make the virus spread easily from person to person.

That’s exactly what happened with COVID-19. And it could happen again with bird flu.

A plausible scenario, but not inevitable

The good news? Not every expert is panicking. The U.S. Centers for Disease Control and Prevention (CDC) says the risk of bird flu spreading between humans is still low—for now. But all it takes is one big mutation to change that.

As Quammen puts it: “It’s not a certainty, but a very, very distinct possibility.” So, no need to panic—but we definitely need to pay attention.

What Can We Do About It? Be Ready

COVID-19 taught us that preparation matters. Here’s what experts recommend:

• Keep a close eye on viruses that spread from animals to humans.
• Improve health and safety on farms.
• Share scientific info clearly—enough to inform people without scaring them.
• Invest in research for vaccines and treatments before it’s too late.

Final Thoughts: Take This Warning Seriously

David Quammen isn’t trying to scare anyone. He’s just reporting what he sees. And right now, he sees a virus that’s getting closer to spreading among humans.

Bird flu may not be the next pandemic—but it could be. It has the right conditions. That means we need to stay alert, stay informed, and take action while we still can.

The warning is out there. It’s up to us to respond before it’s too late.