Hello and welcome to “Avian Flu 101: Your H5N1 Bird Flu Guide.” I’m your host, and I’m here to help you understand the basics of bird flu—also known as avian influenza—using clear, simple language. If you’ve ever wondered what bird flu is, how it spreads, or how concerned you should be, you’re in the right place.

Let’s start with some 101-level virology. Bird flu is caused by a virus called influenza A, specifically a subtype known as H5N1. Viruses are tiny germs with simple structures—just some genetic material wrapped in a protein coat. The “H” and “N” in H5N1 refer to proteins the virus uses to enter and exit animal cells. According to the CDC and health experts, this virus naturally spreads among wild birds, especially waterfowl like ducks and geese, but it can also infect domestic poultry and, occasionally, mammals—even cats, dogs, cows, and humans.

The H5N1 bird flu is called “highly pathogenic” because it can quickly sicken and kill poultry, sometimes wiping out entire flocks within 48 hours. What makes H5N1 especially tricky is its ability to mutate, meaning the virus can change over time. This is why scientists monitor it closely—if it evolves to spread easily between people, it could cause a major outbreak.

Let’s look back for some historical context. H5N1 was first found in birds in 1996, and by 2022, nearly 200 million chickens in the U.S. had been infected, according to the University of Florida. Outbreaks have happened around the world, with a few rare human cases, mostly among people who work closely with infected birds or livestock. Most people who get H5N1 have mild symptoms like pink eye, fever, and mild respiratory issues, but in rare cases, it can be severe or even fatal.

Now, let’s talk terminology. If you hear “avian influenza,” “bird flu,” or “highly pathogenic avian influenza” (HPAI), those all refer to the same family of viruses, of which H5N1 is one subtype. Seasonal flu, pandemic flu, and bird flu can sound similar, but they’re not identical. Seasonal flu is what most of us get vaccinated against every winter—it spreads easily between people. Pandemic flu is anytime a new flu virus spreads worldwide, like the 2009 H1N1 pandemic. Bird flu, though, mainly spreads among birds, not people—for now.

So, how does bird flu get from birds to people? Think of a garden hose. The water inside—that’s the virus—only gets to you if you open the spigot or touch the water directly. In the real world, the virus moves through body fluids: an infected bird’s saliva, droppings, or even milk. People get infected when they touch these fluids and then touch their eyes, nose, or mouth, or breathe in dust contaminated with the virus. Eating fully cooked poultry, eggs, or pasteurized milk is safe, because the heat kills the virus, according to the Cleveland Clinic.

How does H5N1 compare to seasonal flu and COVID-19? Unlike seasonal flu, which spreads easily between people and usually causes mild symptoms, H5N1 rarely jumps to humans and even more rarely spreads person to person. According to academic comparisons, COVID-19 (caused by SARS-CoV-2) spreads much faster between people and causes a wider range of symptoms, including loss of taste or smell, skin rashes, and sometimes damage to organs beyond the lungs. Both COVID-19 and H5N1 can be deadly, but COVID-19’s much higher transmission rate makes it a bigger public health concern for most people right now.

Let’s take some common questions. Is there a bird flu vaccine? Yes, but right now vaccines are mostly available only for people at high risk, and they may not match the latest virus strains. Can your pets get bird flu? Yes—cats are especially vulnerable, and keeping them away from wild birds or raw milk can help protect them. What should you do if you see a dead bird? Don’t touch it. Report it to your local wildlife agency.

If you must handle sick or dead animals, wear gloves...