You may have heard the recent revelations that the H5N1 bird flu virus has been spreading among dairy cows and that fragments of avian influenza have appeared in milk being sold at stores. That’s left one question flying about—should you worry about the bird flu? Well, the short answer is “yes” but not in a go-and-hoard-toilet-paper-again panic sort of way.
Just because this highly pathogenic strain of bird flu has jumped to cattle and a dairy worker in Texas got infected with the virus doesn’t mean that you should necessarily have a cow, so to speak. The dairy worker survived the infection. Plus, fragments of the virus in milk is not the same as having complete versions of the virus that can infect humans. It’s sort of like the difference between an Uber showing up at your house versus a steering wheel and a couple tires.
Whenever a harmful virus—whether it’s an influenza virus, a coronavirus or some other virus—is circulating widely among some other animal population, the things to watch out for is whether that virus has the capability of consistently infecting humans and what the human immune response to this strain might be. Avian influenza strains are different from human influenza strains. Your immune system is much more used to dealing with human influenza strains since over the years you’ve probably been exposed to people infected like that guy who sits next to you on an international flight and talks your head off about his life story while coughing. Getting the flu vaccine each year can keep your immune system familiar with human influenza strains as well and is a much more pleasant and safer alternative to getting sick with the flu.
By contrast, unless you happen to be the dairy farmer in Texas, your immune system likely hasn’t had a chance to experience the wonders of being infected with the H5N1 avian influenza virus. That would make it a novel or new virus to your immune system. Thus, the risk is that your immune system wouldn’t know how to fend off this virus. Or worse, your body could react like a guy on his first ever date, trying all sorts of random things that could actually do harm to itself or yourself. That’s what happened when the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first hit everyone in 2020. Immune systems in many cases overreacted, often leading to body damage and death.
So far, aside from an occasional human infection, there’s been no indication that this H5N1 avian influenza virus can consistently jump to humans. That should be comforting news for you, assuming that you don’t have wings, a beak or an udder. There’s no reason right now to avoid eating beef or drinking milk, unless you happen to be vegan.
But one thing that you should be udderly aware of is that flu viruses can mutate fairly rapidly. Every time the virus replicates, it can make mistakes—sort of like a drunk person operating a copy machine. Those mistakes essentially result in mutations in the genetic code of the virus copies. Many of these mutations may not affect how the virus functions. Some may make the virus weaker. Every now and then a mutation arises that makes the virus stronger. It can help the virus cause more severe symptoms. The mutations may even help the virus jump to new species of animals, which would lead to an “uh” but not necessarily an “oh” yet.
Even if the H5N1 avian flu virus were to jump to humans, don’t utter the “p” word just yet. For a pandemic to even be a possibility, a novel virus has to demonstrate sustained human-to-human transmission of the virus. In other words, a human infected with the virus has to be able to routinely pass it along to another human. There’s certainly been no indication of that yet for the H5N1 avian influenza virus with an emphasis on the word “yet.”
Concerns about avian influenza causing a human pandemic are certainly not new. Ever since the early 2000s, scientists have been warning political and business leaders that bird flu strains could make the jump to humans. During the first decade of this century, infectious disease modelers who comprised the National Institutes of Health (NIH) Models of Infectious Disease Agent Study (MIDAS) network—including myself—developed and ran computer simulation models that showed how avian influenza could spread and its potential big impact. These simulation experiments also showed the value of layering different interventions such as vaccination, medications, testing, surveillance, contact tracing, face masks and social distancing where appropriate. The thought is that it will only be a matter of time before avian influenza viruses mutate enough to be able to infect humans and have sustained human-to-human transmission.
Thus, the worry right now should not be a panic. Instead, the worry should be just enough to spur everyone—especially political and business leaders—to be a lot more proactive about preparing for a potential jump to humans and being more ready to contain the virus quickly should a jump happen. Our country doesn’t seem to have learned the lessons that it was supposed to learn from the Covid-19 pandemic. It should have prompted the U.S. to set up a much more comprehensive and effective virus surveillance system. There should have been more efforts to build up the public health workforce and greatly shore up and expand the pubic health system and its ability to respond to outbreaks and epidemic. It should have motivated much greater investment into science.
Instead, things in many ways have gone the opposite. There is even more anti-science rhetoric and politicization of what should be scientific issues and concerns. Thinking has gotten even more short term with failures to invest more for the future. The trouble is when you continue to ignore warning signs about the next possible pandemic, nature can have a way of giving everyone the bird.
