Name: Everything you need to know about BIRD FLU
Uploaded: 2025-06-18T10:37:04.000Z
Duration: 7 min 25 s
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As bird flu continues to spread across the globe, not only in animals, but now in more Americans than ever in history, many people are starting to ask the dreaded question.

Is this the next pandemic that humans are about to face?

Are all the headlines and news articles accurate or simply stoking fear to generate clicks?

This video will help you understand what's actually going on as it currently stands.

What happens if you catch bird flu, how close it is to becoming a pandemic, if at all, if you should be worried and what we can even do.

H5N1, the current subtype of bird flu being talked about is an influenza A virus, which are the kind of viruses responsible for the most global pandemics in human history more than any other pathogen.

H5N1 first infected humans in 1997 in China with its largest impact between 2003 to 2015 in Southeast Asia.

Both outbreaks required massive efforts to contain, including killing entire domestic poultry populations.

And while levels did taper off, the virus continued to mutate and travel throughout bird communities, both wild and domestic.

In 2024, it seemingly took a dangerous turn, this time spilling into cattle populations.

Most of these infections were in the US where it began to infect humans.

And now the strain has a catchy title, which is 2.3.4.4BH5N1.

This variant has shown mammal to mammal transmission in European fur farms amongst South American marine mammals like these sea lions, and most recently between the US dairy cattle, to domestic cats, to raccoons, mice, and now humans.

So not only has it infected over 136 million birds of that about 500 different bird species, it's now infected over 48 different mammal species.

And this is causing extreme concern in the scientific community.

Now, when looked at through the lens of something like COVID, the numbers in humans seem small.

Since the start of 2024, around 80 people internationally have been infected, 67 of which were in the United States with one dying.

And that's partially because of how influenza transmits.

On its surface, it has something called a hemagglutinin or HA, which binds to specific receptors in a potential host.

And this bird flu isn't optimally adapted or compatible to the receptors in our human upper respiratory tract.

This area is important because if infected, we end up coughing or sneezing out the virus and infecting others.

But we do have some of these receptors much deeper in the lungs, as well as in our eyes, and that's likely how it's infected humans so far.

In fact, a key symptom of H5N1 is conjunctivitis, also known as pink eye. 93% of people infected have had pink eye, 49% experienced a fever, and 36% had respiratory symptoms.

But because we don't have a ton of these receptors, it means that all the infected humans have been in direct contact with an infected animal.

Whether that's been through a dairy cow spreading respiratory droplets into a farmer's eye, direct contact with poultry, or just being in highly contaminated areas like a farm or a live animal market.

In this sense, we're lucky as there's no evidence yet of human to human spread.

Which brings about the question, can it become better adapted to our receptors?

And this is where the legitimate fear around this new pandemic comes into play.

In fact, a study was published in December of 2024 that showed a single mutation of the virus's hemagglutinin from a glutamine to a leucine at residue 226 could change it from an avian to human specific virus.

The modified virus was able to bind to human receptors in the upper respiratory tract, which would make it easier to pass from human to human.

Now, will the virus achieve this specific mutation naturally?

We can't know for sure, but the fact that it's spread to so many different mammal species is only giving it more chances to evolve and adapt.

The more mammal to mammal transmission we see, the greater this risk becomes.

In fact, samples from the first human case contracted from a dairy cow already showed a mutation of something called the polymerase protein, which helps the virus replicate by using the host cell's machinery.

This mutation from cows allows increased proliferation more effectively than any bird flu virus before.

And the newest strain of H5N1 is better at binding to human epithelial cells in airways than before.

Not to mention influenza viruses are quite good at recombining.

And if it gets into a human that's already infected with another human influenza virus, there's an opportunity for it to exchange genetic material, which could make it even better suited for human transmission.

Spillover into swine would also be a large issue because they can be suitable hosts for even more reassortment.

But it's important to know that there are other barriers as well.

These hemagglutinin proteins would need to be able to tolerate lower pH levels.

If not, the virus won't be able to survive in the acidic microenvironments of airborne particles or survive in mammalian respiratory secretions.

And there are many opportunities for us to minimize the spread, whether that be through close monitoring of the mammalian cases in sea lions, mink, and cattle to be aware if these mutations are taking place.

We know the bird flu is spreading amongst mammals in the US and Canada in around like 900 herds, but we are only testing in certain states.

Scientists are calling for a stay at farm order, keeping cattle within farms, not allowing them to spread.

Also, farmers should be using PPE, not just masks, covering their face, especially their eyes when working with sick cattle.

And we need increased testing on farms of the animals, of the patients, of the livestock, of the animals and mammals in and around these farms as well.

The good news is that unlike a novel coronavirus like COVID, we could have vaccines ready for this pandemic as flu vaccines are much more researched.

It's also hypothesized that many people may already have better immunity to these flu viruses because of exposure to human influenza.

Unfortunately, that makes it a little scarier for younger people who haven't yet been exposed to as many flu viruses or flu vaccines over their lives.

In fact, one Canadian teenager was in critical condition for over a month and virus sequences suggest it had mutated within the patient, moving towards some of the necessary adaptations needed to better infect humans.

Other avian flu viruses have petered out in the past.

There also could be other mutations or situations needed that scientists aren't aware of right now in order for this to become a global pandemic.

But Louise Mankla, a virologist at the University of Pennsylvania, said this feels the closest to an H5 pandemic that I've ever seen.

And Seema Lakhtawala, a flu researcher at Emory University, says if H5 is ever going to become a pandemic, it's going to be now.

Despite the potential fear and a lot of anxiety that the science community might be having around this, it's important to know that the level of risk for the general public is low, and even the level of risk for farm workers right now is low to moderate.

Get your yearly flu vaccine if you haven't already.

Not only will it protect you from the seasonal flu, it may help decrease reassortment with H5N1 and could potentially minimize symptoms should you catch it.

Scientists are developing and testing vaccines for the currently circulating H5N1 virus, and researchers showed that some of the stockpiled vaccines from the mid-2000s could help.

It's not time to panic, but it's time to be warned and informed.

If you want to hear us talk a little more in depth about the bird flu, we have a whole podcast episode on it.

I'll link it on screen or in the description.

Otherwise, feel free to share this video with someone in your life who maybe is feeling afraid or uninformed about this bird flu.

Thanks so much for watching, and we'll see you ASAP for some more science.