One doesn’t usually speak about Avian Flu in the same sentence as the COVID pandemic. But there are multiple links including likely animal origins, past versions from the same family of the infectious disease, potential for rapid transmissibility, the economic havoc, broader effects on health systems, initial measures other than vaccines to contain the outbreak—and that science can provide new ways to do so.
Of course, there are major differences, with Avian flu rarely transmitted to humans. But it can happen and it has just happened in the United States last week: An unnamed prisoner contracted the infection during a work release assignment at a farm in Montrose county in Colorado where workers were euthanizing an infected flock.
Outbreaks of bird flu in people do happen and there was an earlier major outbreak in 2014 that brought new insights and understanding. Interestingly, on that occasion, China once again took center stage; an H3N8 strain of bird flu was detected in humans there for the first time, in China’s central province of Henan. A four-year-old boy who had been in contact with sick chickens and crows raised at his home had become infected, according to reports from China’s National Health Commission.
COVID is one of the worst human pandemics in over 100 years. Still, it is worth having a sense of where we are in relation to Avian Flu, where it might go, and what is being developed in the laboratory to mitigate harm.
What Happened in the Past?
The traditional control method, and the one currently employed, is depopulating all of the infected birds and disposing of their carcasses as safely and quickly as possible, usually through compost. This has dramatic knock-on effects on employment at poultry farms and eventually, in the case of a widespread infection, on the price of poultry products. Here is a report from Canada as the country is currently swept by the Avian Flu:
This culling-euthanizing strategy is the same one that was followed when an outbreak early this century triggered a major global response, led by the World Bank, known as the Global Program for Avian Influenza Control and Human Pandemic Preparedness and Response (GPAI).
This multisectoral program comprised 72 projects in 60 developing countries in all regions and received $1.3 billion in financing from the World Bank.
A coordinated global response to the threats of avian influenza pandemics resulted in the financing of $4 billion from 35 donors from 2006 to 2013. Developing countries strengthened their capacity for early and effective disease control, bringing substantial public health and economic benefits to the countries and to the world.
According to Harvard University professor and former US Treasury Secretary Lawrence Summers, “[veterinary and human public health systems are] probably the single most important area for productive investment on behalf of mankind,” in essence, endorsing a One Health approach.
Circulation of the highly pathogenic avian flu virus was reduced, lessening the likelihood of an even broader worldwide pandemic, and improved public health systems for reducing locally relevant health threats.
New Outbreaks in the US and Europe: Sweeping through the wild bird populations, poultry birds are also affected
“As has often been the case, wild birds play a major role in the start and spread of avian influenza viruses. Surveillance for these viruses is sporadic and geographically biased.
A newly arrived bird flu is currently sweeping through wild bird populations in the United States and Canada, and that spells trouble for poultry farmers who have been doing their best to control this flu outbreak in their flocks.
Some 24 million poultry birds like chicken and turkeys have already been lost, either because they died from the virus or were killed to prevent its spread.
But unlike a similar bird flu outbreak seven years ago, this one is unlikely to just burn itself out. That’s because this particular flu virus seems capable of hanging around in populations of wild birds, which can pass the virus on to poultry farms. Biosecurity measures need to be taken by farmers but they can fail when they are not taken in time.
While chickens and turkeys with the virus quickly sicken and die, some waterfowl can remain healthy with the virus and carry it long distances posing further threats as they travel across the country. This pathogen will also get a chance to genetically mingle with the flu viruses that are already circulating in the U.S. and Canada.
“What that means for the virus in terms of how it evolves, how it changes, we just don’t really know,” says Richard Webby, a flu researcher at St. Jude Children’s Research Hospital.
However, the US Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS) has primary responsibilities for detection and control procedures and leads this effort, taking action to ensure a continued rapid response to the Avian Flu.
USDA issued the first warning over bird flu three months ago:
It is noteworthy that USDA-APHIS “has [for decades] taken a One Health approach in its efforts to eradicate and control diseases …” And, as is to be expected given the One Health approach, USDA-APHIS works in close collaboration with the US Centers for Disease Control and Prevention.
In Israel, when this virus hit an area where about 40,000 common cranes had gathered for the winter, “they lost a reported 8,000 of these birds over the course of a couple of weeks,” says Richards. “So, when you start thinking about losing 20% of a specific population of wild birds, that’s a pretty substantial impact.”
If this virus sticks around in wild bird populations — which some scientists think is likely — poultry farmers may need to just learn to live with the problem.
Ron Fouchier, a virologist at Erasmus Medical Center in the Netherlands, noted a similar situation in Europe: “But there’s no guarantee for [the virus to disappear],” he says, “ as we’ve seen in Europe now that this virus has remained present for several years in a row.” Since December, farmers in Europe have had to cull more than 17 million birds. “So that’s very similar to the situation in the U.S.,” says Fouchier. “And we are seeing massive die-offs in wild birds.”
A Possible Vaccine Response to Avian Flu
A newly developed influenza vaccine against a potentially pandemic variant of the influenza virus, the H5N1 subunit virus, has been shown to be highly effective in younger and older adults. In a randomized, phase 3, multicenter study, the experimental vaccine performed exceedingly well. It was evaluated in a study based on an H5N1 subunit influenza virus developed by Seqirus Inc, Holly Springs, North Carolina.
“Like other avian influenza viruses, influenza A (H5N1) viruses primarily circulate among wild and domestic birds and poultry, and these viruses do not normally infect humans,” Matthew Hohenboken, therapeutic area head, pandemic and other vaccines, Seqirus, told Medscape Medical News.
“Given this, most of the population has no existing immunity to influenza A (H5N1), so if the virus were to become transmissible from person to person while retaining its capacity to cause severe disease, the consequences for public health could be severe,” he added. The study was published online on March 23 in Vaccines.
These are early days in Avian flu vaccine development and availability, and in the future we may look to some of the new technologies, such as mRNA, to provide faster and more easily produced vaccines.
But the idea of getting ahead of a possible epidemic or pandemic in poultry is one that could cross over to humans. It certainly warrants attention, given what we have experienced and are experiencing with COVID-19.
And this is only the tip of the iceberg for potential future zoonotic diseases emerging into pandemics equal to or worse than COVID, such as the Nipah virus which has a 40 -75% death rate for humans. Among other interesting developments, Nipah vaccine development programs for a single-dose vaccine are underway.
But the point is this: The next big one could be right around the corner.
We need to pay greater attention and resources to the fact that an estimated 60% of known infectious diseases and up to 75% of new or emerging infectious diseases are zoonotic in origin, i.e. diseases transmitted from animals to humans. And the lesson to be drawn is clear: it is becoming increasingly likely that what works in one species may work in another.