This piece, “Bird Flu", appeared on page 24 of the Fall 2024 issue of Chicago Life Magazine.
Bird influenza does not pose a big risk to humans today. But keep an eye on it.
It can be viewed using this link: Chicago Life Magazine - Bird Flu
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As of now, there are even fewer people with bird flu than had monkeypox when I wrote a piece about the first infectious scare to come around after COVID, published in the spring 2021 issue of CHICAGO LIFE and titled, “CHILL!--Putting Monkeypox in Context.” There have been just 14 human cases of avian influenza so far, compared to 45 total cases of monkeypox when that article appeared three years ago. Now consider that there were 65,000 new cases of COVID that same week. Monkeypox is still plenty rare in this country. At its peak this year, the 7-day average of new cases of monkeypox was 13 per day, declining to 1 per day by mid-September. The main reason for such low incidence is that monkeypox is acquired only by close contact, like kissing and penetrative sex.
On the other hand, influenza viruses, including the avian (bird) flu strain, are mostly transmitted by droplets and aerosols that are coughed, sneezed or just breathed out by an infected individual and inhaled or otherwise introduced into nose or eyes by others. All but one of the 14 people who have come down with bird flu breathed heavy doses of the virus. Nine were employed in the poultry industry. Four worked with cattle. One got it from an undetermined source. Other creatures have not been so lucky. The infection has reared its head in 13 states, killing over 100 million chickens and infecting more than 200 cattle herds (dairy and meat), as well as cats, goats, racoons and wild birds.
When it comes to avian influenza, humans have been quite fortunate. We are not very susceptible to that infection; those who get it aren't terribly sick; and the bug doesn't pass from one person to another. The few people who acquired bird influenza had intense exposure to the virus in chicken coops or processing plants and in dairy barns or beef slaughterhouses. They mostly developed pretty mild flu symptoms: fever, cough, muscle aches, sore throat, shortness of breath and runny nose. That's all.
The reason you need a flu shot every year is because the constituents of the protein coat (antigens) of the virus mutate between epidemics so that, unlike the decades of immunity that result from vaccines against the genetically stable measles and polio viruses, the response that your immune system developed as a result of last year's influenza shot or infection may not suffice to protect you from this year's version.
Many viruses that afflict humans start out in other animals then mutate in ways that allow them to penetrate human immune defenses. Monkeypox, of course, originated in monkeys. The HIV virus that causes AIDS in humans jumped over from chimpanzees. We know that when people and animals live together at high density it fosters transmission of viral mutations between animals and humans. Remember swine flu? In China, where that epidemic originated, a lot of its 434 million pigs (as of April 2024) live in close proximity to a lot its people (1.423 billion in 2023).
Viruses swap antigens among themselves. There are always plenty of different strains of influenza virus around. If one or more of the agents that currently live in animals or people were to pass to an avian flu virus the ability to cause severe disease in humans, as well as easy transmissibility, we could be in for it. That's why I've withheld “CHILL!” from the title of this piece. There's room for just a bit of worry.
Let me quote what Dr. Jennifer Nuzzo, Director of the Pandemic Center at the Brown University School of Public Health had to say about avian influenza.
…we have no evidence so far that this virus can easily infect human beings or that it can spread between human beings easily in a sustained fashion….The second we know someone gave it to someone else relatively easily, that's a new pandemic, and it will be around the globe probably in a matter of weeks.
The government has granted $150 million to Moderna to develop an MRNA avian flu vaccine. Even if we had a safe and effective product now, it's not nearly time to start inoculating humans. And it would be impossible to scale vaccine production up enough to help the chicken industry. Between broilers and layers, there are about 1.5 billion birds alive in the U.S. at any time.
There is also money being put toward developing a rapid test for bird flu, similar to the COVID test kits many of us have outdating in our closets. The incidence in humans is too low now to begin widespread testing of individuals for infection, as we currently do for human influenza and COVID, or to be estimating disease burden in populations through sewage testing.
The avian influenza virus would have to do a lot of morphing to acquire the ability to evade human immune defenses, plus cause serious illness, plus achieve high person-to-person transmissibility. The need to undergo so much genetic change makes a serious bird flu epidemic fairly improbable in the foreseeable future. So don't worry much about bird flu. But do pay attention to news about it.
Here are a few things you can do in the meantime:
- Get a flu shot. It will probably protect you at least some from this year's version of human influenza and could overlap with avian flu virus, in the unlikely case that a bird flu epidemic were to occur.
- While you're at it, get the latest COVID shot because the coronavirus which causes that infection is another one that is constantly changing its surface antigens and eluding human immune defenses.
- Insist that local, state and federal public health institutions be better prepared for the next pandemic than they were for the last one.
- Be thankful you're not a chicken.
