Virologist: These steps can halt the spread of bird flu and ‘prevent a human epidemic’

As bird flu continues to circulate among wild birds and domestic livestock, public health officials are increasingly concerned about the potential for the virus to become transmissible among humans and potentially cause an epidemic. 

So far, humans have only contracted bird flu from contact with infected animals and cannot pass the virus to other humans. 

In a recent commentary published in Nature Medicine, Tulane University virologist Bob Garry outlined the steps he sees as essential to preventing H5N1 from developing human-to-human transmission – and what strategies should be employed if the virus is able to evolve into a greater threat.

Bird flu is circulating widely with spillover from wild birds into poultry, cattle, cats, rats and some humans. What’s the main message from your commentary outlining ways to prevent and respond to the virus?

Bob Garry: We need to take bird flu seriously. Preventing the virus from adapting to develop human-to-human transmission is the biggest priority to prevent a human epidemic. If the bird flu did turn into a human transmissible virus, that would potentially make the COVID-19 pandemic look like a walk in the park, and even the low rate of severe disease we’ve seen so far would be enough to cause a crisis. But there are concrete steps we can take to be better prepared. 

What are some of those steps? 

BG: We need to eliminate circulation of the virus among dairy cows and protect farm workers. That means more screenings, testing of bulk milk tanks, offering free personal protective equipment to farmers and increasing human screening for those who come into contact with potentially infected animals. Even with these steps, a human transmissible strain can emerge. We would need to ensure ways to circulate and disinfect the air in schools, homes and workplaces, prepare labs for potential mass testing and of course, repair public trust after the COVID-19 pandemic. 

Is the potential for mutation the biggest concern with bird flu? 

BG: Yes, we’re most worried about single mutations or things that can lead to it developing transmissibility between humans. One way a virus can do this is via reassortment with other flu viruses. States are seeing a wave of flu cases right now and if you get one person or one animal infected with both viruses, they can reassort into potentially more pathogenic, more transmissible viruses. A lot of pandemics have started that way so we need to eliminate as much circulation of the virus as we can. 

Colorado mandated weekly testing of its dairy farms’ milk tanks and cleared herds of H5N1, the only state to do so. What obstacles do farmers in other states face to following suit? 

BG: It’s tough to ask someone to give up their income, their livelihood, for the greater good. And many governments won’t step in to halt a major industry to potentially stop something that may or may not happen. So that can be a hard sell, and we need to better support farmers by offering free PPE. 

Canada just ordered a supply of bird flu vaccines, and the CDC has identified candidate viruses that can be used to develop vaccines. What’s the current bird flu vaccine landscape look like? 

BG: You have to be prepared to ramp up production based on whichever strain of the virus is in circulation. In the meantime, we really need to get people better information about what the risks are. If you get the flu, stay home. Simple things like that can heavily impact how deeply this virus would penetrate, if we end up with bird flu circulating among humans. We have to learn from the COVID-19 pandemic and improve our science communication. Viruses like this pose a health threat, but as we’ve seen with the price of eggs, they also pose economic problems and can hinder someone’s ability to provide for their family. 

The first transmission of bird flu to humans was in 1997. Is messaging made more difficult by how long we’ve known about the virus. 

BG: I think people are more hesitant to see a threat because it has been around for a while. And it hasn’t led to a pandemic yet, but the potential is there. When I saw the virus get into our dairy cattle, I thought, “Wow, something may have fundamentally changed about this virus.” If it’s developed the ability to spread in cows, how many more steps does it need to take before it spreads in people? There’s something about the current strain that feels a bit more urgent. You don’t want to create a panic. But the flu is a serious illness, particularly for older individuals and those at risk. Particularly H5 bird flu, which in prior years has historically had about a 50% case fatality rate, irrespective of age or preexisting condition. So far, these current strains of bird flu are less lethal, and only a couple of these cases in humans have been fatal, but each animal that’s infected is a potential mixing pot of strains that can create an even more transmissible, pathogenic virus.

Robert Garry is available for media interviews. To arrange an interview, please contact Andrew Yawn, assistant director of media relations at Tulane University, at ayawn@tulane.edu.