Bird flu, also called avian flu, is one of many hot button issues in the preparation for the American 2024 Presidential Election Cycle.
One of many common news topics circulating wildly before the election, the bird flu holds a similar public importance as Mpox, reproductive rights, and inflation. Although bird flu cannot hold a candle to rightful concern over widespread national inflation and the state of the U.S. economy, the bird flu that started in 2022 has since forced some hard-working farmers to cull their flocks of chicken as well as herds of dairy and beef cattle. This has devastated family farms and corporate farms alike, forcing bankruptcies and inflating the price of eggs, chicken, beef, and some dairy products due to the sudden lack of supply. Farmers in highly affected areas are lobbying to restrict transport of chicken and cattle as well as expand emergency assistance programs for farms who must cull their infected animals.
Additionally, many are concerned about how the U.S. government will deal with the sudden global importance of the bird flu — the last time the U.S. government had to face the potential of a global pandemic, the response was confusing, slow, and often misinformed. The CDC and U.S. officials under the Biden Administration waited to make decisions about the prevention measures that American citizens were meant to implement in their lives, lacking a significant body of evidence for many measures that were either enforced by law or enforced by the court of public opinion.
Bird flu is not a new virus — in fact, a great majority of Influenza A viruses are avian in origin. Birds are a fantastic carrier of infective viruses, especially wild birds, held by no bounds to national or continental borders. Wild birds are often similar enough in genetic composition to domestic poultry and can give them viruses, which furthers the spread of deadly disease within bird populations.
Additionally, and more relevant to the new strain of bird flu, the virus can sometimes spread from birds to other animal hosts. In this case, the spotlight is on the ability to infect cattle and cause notable mortality in wild birds.
Similarly to COVID-19, the bird flu is not novel to the public either. Before COVID-19, SARS in 2002 and MERS in 2012 served as models for the severity of symptoms and limited spread associated with coronaviruses, so although we were unprepared for the sudden virulence of a new coronavirus, we knew novel COVID-19 symptoms would likely fall in a similar category to previous coronaviruses.
The global public was made aware of the bird flu in 2022. This strain of the bird flu is preceded by the first instance of this specific type of avian flu — in 1997, 18 people in Hong Kong caught a very severe influenza from a poultry market and 6 people died as a result.
With popular concern about pandemics and renewed restriction on public freedoms at a high, the question is: will this bird flu be more like MERS, being short but severe in appearance for humans, or more like COVID-19, a global and pervasive human pandemic?
The Science on the Bird Flu 
Although the bird flu is not a new virus, the new circulating strain from 2022 is a relatively novel strain in humans. The first record of the H5N1 strain of Influenza A was reported in 1996 in Chinese geese, and the first instance of zoonotic, or animal-to-human, transfer was reported in 1997. The H5N1 strain started circulating around wild waterfowl in 2022 and has since started infecting anything from domestic birds to minks to livestock cattle in 2024.
To understand the current bird flu, we must examine the general background of Influenza.
Influenza is a virus that can be found in both animals and humans. The flu virus comes in several varieties: A, B, C, and D.
Influenza C and D are less significant for humans — Influenza C is a strain that tends to infect generate mild infection in humans, pigs, and dogs, while Influenza D is a strain discovered in 2011 that tends to generate infection exclusively in pigs and cattle. Influenza C evidences cases of mild illness, especially in high-risk groups like young children, the elderly, and the immunocompromised. Influenza D has never shown evidence of human spillover, which means that there has never been a case of a human acquiring this infection from swine or cattle.
Influenza B is typically found only in humans with little evidence of zoonotic spread. Because humans are the main host of Influenza B, the mutation rate of the virus is lower. With less hosts available, there is less chance for surprise genetic mutations caused by natural viral replication processes. Due to milder infection and less mutation, Influenza B is known for causing seasonal human illness instead of large-scale pandemics.
Influenza A is the source of major flu illness in humans and the single cause of all flu pandemics that our world has ever seen. Although Influenza A and B have similar means of transmission, Influenza A can infect and spread throughout zoonotic populations just as easily as human populations. While this does not necessarily make the flu more virulent (or more capable of producing rapid or severe infection), it does open the flu to more and more mutations that can spillover into human populations.
For example, if a certain strain of Influenza A starts in Alachua County, Florida, the flu may only spillover into 10 people over the course of 6 months. Yet, at the same time, the flu can spread to bats and the size of the Alachua bat colony varies anywhere between 1,000 and 500,000 bats. If the Influenza A reaches the bats, the virus transmits between up to 500,000 close cases, giving the virus a chance to mutate its genetic code as it constantly replicates its genetic information crossing from host to host. By the time it spills back over into humans, the virus could have gained several important mutations that necessitate different treatment or preventative care.
Influenza A is the cause of pandemics like the Spanish Flu in 1918, Asian Flu in 1957, Hong Kong Flu in 1968, Bird Flu in 2004, and Swine Flu in 2009.
Although these pandemics are all Influenza A, there are more classifications it may be helpful to know when describing the flu pandemics. You may see an H and an N followed by some numbers when reading about the new bird flu pandemic, and here is why they are important.
The H is for hemagglutinin and the N is for neuraminidase, which are specific surface proteins on the viral capsid of influenza.
Think about it this way — the virus is like a suitcase.
The genetic information of the virus is the content of the suitcase, filling the viral “shell” with information like the way you pack clothes into a suitcase. The outside of the suitcase is the viral capsid, holding all the contents of the virus inside. On the outside of the suitcase you typically have a tag that describes where the suitcase is going and a tag that has your information on it. The H and the N of the virus are like those tags, and they determine the “destination” of the virus by tagging specific cell receptors in our body.
The new bird flu spreads through birds, so we call it a Highly Pathogenic Avian Influenza (HPAI). This means that not only is the virus infective and easy to spread, but also that the main host is a traveling animal not limited by borders or landmasses.
With all this in mind, why does THIS bird flu matter to the American population?
H1, H2, and H3 Influenza A pandemics have commonly circled the global population, but it was thought that the flus with higher H numbers (5, 7, 9) could not spillover into human populations. The H5 virus targets avian cell receptors that are not as effective at binding to human cell receptors.
Then, there was a spillover event — the first case of an H5 human infection was detected in Hong Kong in 1997 after an HPAI H5N1 appearance in Chinese geese.
All that to say, not only does the flu have a high chance of spreading through avian sources, but the flu has a high chance of being more severe the more it mutates going through different hosts.
An especially concerning facet of this 2024 A(H5N1) bird flu is that the flu is not only capable of infecting birds and humans, but also cattle. Cattle are vital to the American economy, and upon the back of cattle depends the livelihoods of farmers and ranchers nationally. In January 2024, it was reported that 87.2 million head of cattle are currently roaming American lands, which are all at risk of picking up and spreading this new H5N1 infection.
So what is the hope in this dire situation? It seems like we are on the precipice of a pandemic with a reported 40-60% human mortality rate!
Should We Fear the Looming Bird Flu?
Realistically, we are not on the brink of a natural pandemic, and this is not like COVID-19, and here is why.
Some basic requirements must be met for a virus to cause a pandemic. It has to be highly transmissible from human-to-human, mostly seen through airborne transmission, and cause disease in humans. Additionally, a pandemic is also typically formed by a novel type of a virus, one that leaves the majority of the global population vulnerable to more severe infection.
- First things first, this bird flu is not naturally highly transmissible from human to human.
Although it has a notoriously high mortality in humans who DO become infected with the A(H5N1), the bird flu has not shown evidence of transmission between humans. The folks who do get infected typically spend a lot of close contact with infected fowl or cattle, as evidenced by the nine confirmed U.S. cases as of August 2024.
We currently don’t have the receptor capability to transmit H5 viruses — although we have the ability to catch the H5 kinds of flu viruses, we don’t have the receptor specifically that would allow the virus to enter the majority of our human cells, nor would likely allow the virus to transmit beyond our epithelial lining.
The H1, H2, and H3 flu viruses have shown a propensity for and a high ability to transmit throughout most of our human cells, which makes their pandemic possibility much more significant than H5 strains of the flu.
The concern about a pandemic is borne out of a knowledge that H5 viruses have been able to mutate and develop from avian strains into mammalian cells. While avian influenza strains typically spread amongst bird populations very effectively, they must mutate one or two receptor proteins before effectively transmitting between mammalian cells.
In mammals, it becomes much easier for the flu virus that was once only in wild birds to “switch” sections of the viral genes with a flu that can infect humans, allowing the new mutated flu virus to infect humans and cause a potential pandemic.
Yet, there are more than 5 different specific amino acid mutations that would need to occur within mammalian and avian populations that would allow this to progress to a disease that allows for human-to-human transmission. If we carefully monitor bird flocks, as well as cattle and wild mammals that may eat infected birds, we can watch and see if these mutations would occur as easily in nature as some experts say.
Notably, former CDC Director Dr. Robert Redfield suggests that it would only take a 5 amino acid change in the H5 receptor of the bird flu virus to make the virus more infectious to humans, and the increase in host range from birds to mammals increases the risk.
That may be true, but by using the error rate of RNA polymerase — the mechanism in the Influenza virus that makes copies of the genetic information — we can estimate that the chance of naturally acquiring all of the specific mutations needed would be about 1 in every 10^74. That is 10 with 74 zeros at the end.
The real danger is likely found in Gain-of-Function (GOF) research being done in several labs across the world. GOF experimentation allows for scientists to create “worst-case-scenario” pathogens, also called “enhanced potential pandemic pathogens” (ePPPs), that have not only a high capability to infect and cause disease in humans, but are also very transmissible between humans. These GOF experiments have the capacity to home-brew pandemic viruses, with the stated purpose to predict potential treatments and solutions to these ePPPs if they were to occur naturally.
Two studies done in by labs in the U.S. and in the Netherlands have used GOF experimentation to make mammalian H5N1 more transmissible and more infectious in ferrets, which have been the source of much concern and discussion among scientists and government officials alike.
The study being done in the U.S. is at the University of Wisconsin-Madison under principal investigator Dr. Kawaoka, funded quietly in 2018 by the National Institutes of Health’s (NIH’s) National Institute of Allergy and Infectious Diseases (NIAID) in Bethesda, Maryland — If you recognize the name of the NIAID, it’s because that is the same institution that was previously headed by the famous Dr. Fauci.
The same organization that was alleged to fund coronavirus GOF experimentation that may have contributed to the spread of the global pandemic we know as COVID-19.
On one hand, because of experiments like that, we are able to know how close we are to the “ticking time bomb” of a potential pandemic and are similarly able to prepare for the worst case scenario.
On the other hand, formulating that “ticking time bomb” manually, attempting to contain it after optimizing it to be very transmissible and dangerous to the general public, seems foolhardy and like a recipe for an “accidental” pandemic.
On top of that, the details for such GOF mutation experiments are published online, like an instruction manual for what wires you would need to cut on the “time bomb” to set it off.
- Secondly, A(H5N1) human symptoms aren’t as capable of global spread as COVID-19.
Folks worldwide have firsthand knowledge about COVID-19 symptoms, which include very “cold-esque” patterns of coughing, sore throat, fever, shortness of breath, headache, fatigue, and a loss of taste and smell. New symptoms can include gastrointestinal distress and symptoms can persist long after initial infection, an ailment called long COVID.
COVID-19 spreads by airborne viral particles and droplets, which you encounter either directly from being exposed to that cough or indirectly from contacting a surface with these droplets and touching your face.
A(H5N1) bird flu symptoms in humans are different both because of the natural progression of symptoms and the transmissibility of the virus itself. The symptoms tend to start with a very high temperature/feeling hot and shivery, conjunctivitis (pink eye), aching muscles, headache, and mild upper respiratory symptoms like a mild cough and runny nose. They then progress to diarrhea, stomach pain, chest pain, and bleeding from the nose and gums. Notable symptoms that differentiate the bird flu from a typical Influenza are the early onset of conjunctivitis and bleeding from the nose and gums.
If you think about your typical experience with a cold, much more similar to the symptoms of COVID-19, you would think of a runny or stuffy nose, a sore throat, fatigue, myalgia (muscle soreness associated with viral infection), and a nearly unstoppable cough.
If you think about your typical experience with the flu, much more similar to the symptoms of H5N1 bird flu, you would think of fever, fatigue, headache, stomach aches, and maybe a cough. Add in some pink eye and you have the typical symptomatic onset of the bird flu.
With COVID-19, the virus was optimized to spread quickly and was VERY capable of infecting human cells — both respiratory cells and cells designed to prevent infection in our immune system called macrophages — which made it a prime pandemic pathogen.
The H5N1 bird flu is currently not capable of attaching to human receptors en-masse, making the likelihood of human-to-human transmission currently zero. Not exactly the perfect pandemic potential that some have been fearing.
- Masking as a form of source protection from bird flu may cause more infection.
It makes sense that a solution to a respiratory illness would be to cover a cough, the distributor of the illness particles. Although the efficacy of N95 and fabric masks is questionable for the size of the COVID-19 particles, it follows logically that creating a natural barrier to spreading the virus would be the desire of many.
While COVID-19 and the H5N1 bird flu symptoms share similarities, the main differentiators would likely make masking and COVID-19 protocols even LESS effective for the H5N1 bird flu.
One major issue within the issue of masking is that it is supposed to be part of a campaign promoting general health — it is not the end all be all of pandemic protection.
The WHO published their guidelines for masking in December 2020, after almost 9 months of dealing with a pandemic sweeping the globe, and part of their guidelines note that “the mask alone is insufficient” to prevent spreading illness. They also note that misuse of the mask, like pulling on the straps, touching the mask when on your face, and adjusting the mask can prevent full efficacy of the prevention measure.
So masking, when used improperly, could and can actually serve to further COVID-19 transmission, as constant adjusting of an unnatural piece of fabric on your face can actually bring aerosols and fluids carrying the virus closer to your face.
Why would anyone think that an illness with proportionally less respiratory symptoms than COVID-19 should be prevented by masking?
With the only symptoms of H5N1 bird flu in one of the first U.S. cases being conjunctivitis (pink eye), transmissible by touching one’s eyes and then a surface, it doesn’t make sense to introduce masking as a preventative measure. Masking would serve to bring people’s hands more consistently towards their face and their potentially itchy eyes, which is how the virus spreads.
Maybe we could all wear big antiviral goggles to prevent the spread!
(If you are reading from the U.S. government, that is a joke. Not a scientific proposal.)
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