The Avian Flu Is on the Move: Beware

In his 2012 book, Spillover: Animal Infections and the Next Human Pandemic, David Quammen warned us that a pandemic was inevitable.  He based this on the rapidity with which dangerous new zoonoses were appearing.  That term refers to a disease being transferred from an animal to a human.  He described humans as an “outbreak,” a species whose population exceeds a level where its viability can be assured.  In the animal world, such outbreaks eventually end either from a lack of resources or the propagation of a disease that greatly scales back the population.  To support the notion that a dangerous virus lies in our future he constructed a list of recent viral appearances.

“If you assembled a short list of the highlights and high anxieties of that saga within recent decades, it could include….Machupo [1959]….Marburg (1967), Lassa (1969), Ebola (1976)….HIV-1 (inferred in 1981, first isolated in 1983), HIV-2 (1986), Sin Nombre (1993), Hendra (1994), avian flu (1997), Nipah (1998), West Nile (1999), SARS (2003), and the much feared but anticlimactic swine flu of 2009.” 

Timing forced him to miss MERS (2012) which was identified in the year of his publication, and there could be some I haven’t heard about.  And now we have another deadly coronavirus, COVID-19 (2019).  All of these can kill infected humans, but in most cases the transmission to humans was too limited, as of yet, to create a pandemic.  SARS and COVID-19 were the exceptions.  We were lucky with SARS, but not so lucky with its successor.  Fortunately, the mortality rate for COVID-19 was low compared to some of the viruses in this list.  Quammen and epidemiologists in the 2012 period were focused on avian/bird flu as the great threat to human existence.  It existed mostly in domesticated bird species and would only rarely be contracted by a human, usually someone in constant contact with the animals.  However, when contracted, death was a common outcome.  The fear was that this flu virus might mutate into a version that could infect humans more readily and then be transmitted between individuals.  This virus, H5N1, does its damage via eye infections, pneumonia, including viral pneumonia, acute respiratory distress, and inflammation of the brain and heart. 

Recent events suggest that the virus is mutating and perhaps moving in our direction.  This sourceindicates the rate of infections within domesticated animals has tripled over the record rate of last year.  Quammen returned recently with notice that avian flue was now spreading to non-avian wild species and might be showing greater ease at infecting humans in A Dolphin, a Porpoise and Two Men Got Bird Flu. That’s a Warning to the Rest of Us.  And then there was the recent article: An Even Deadlier Pandemic Could Soon Be Here by Zeynep Tufekci.  She provides this information.

“Bird flu — known more formally as avian influenza — has long hovered on the horizons of scientists’ fears. This pathogen, especially the H5N1 strain, hasn’t often infected humans, but when it has, 56 percent of those known to have contracted it have died. Its inability to spread easily, if at all, from one person to another has kept it from causing a pandemic.”

“But things are changing. The virus, which has long caused outbreaks among poultry, is infecting more and more migratory birds, allowing it to spread more widely, even to various mammals, raising the risk that a new variant could spread to and among people.”

“Alarmingly, it was recently reported that a mutant H5N1 strain was not only infecting minks at a fur farm in Spain but also most likely spreading among them, unprecedented among mammals. Even worse, the mink’s upper respiratory tract is exceptionally well suited to act as a conduit to humans, Thomas Peacock, a virologist who has studied avian influenza, told me.”

The question we face is how to respond to this information.  There are entities in place that attempt to track the emergence of epidemics and could indicate the existence of a new viral threat, but that mission depends on the ability to detect and pass on the causes of infections.  And it depends on our society being aware of and concerned about the possible threat.

“…quick testing should be widely available and easy to obtain globally, especially for poultry workers and people handling wild birds or other wildlife. And current testing capabilities should be quickly expanded. There are 91 public health labs in the United States that can test for H5 influenza. Positive results are sent to the Centers for Disease Control and Prevention, where further analyses can detect H5N1 within about 48 hours. But plans should be in place to increase the amount of tests and testing facilities in case demand ramps up.”

Vaccines have been developed for this type of flu, but how fast could they be produced in order to contain an outbreak?

“Perhaps the best news is that we have several H5N1 vaccines already approved by the Food and Drug Administration whose safety and immune response have been studied.”

“The U.S. government has a small H5N1 vaccine stockpile, but it would be nowhere near enough if a serious outbreak occurred. The current plan is to mass-produce them if and when such an outbreak occurs, based on the particular variant involved.”

“There are several problems, though, with this approach even under the best-case scenarios. Producing hundreds of millions of doses of a new vaccine could take six months or more.”

Existing vaccines use the now old-fashioned method of creating doses from an egg, a slow process.  The mRNA-based techniques could be funded to prepare vaccines that would be produced faster, but is there the will to do that?

“The mRNA-based platforms used to make two of the Covid vaccines also don’t depend on eggs. Scott Hensley, an influenza expert at the University of Pennsylvania, told me that those vaccines can be mass-produced faster, in as little as three months. There are currently no approved mRNA vaccines for influenza, but efforts to make one should be expedited.”

Even if all resources are put in play, it would take a very long time to vaccinate the world, as the coronavirus experience has shown.  A lot of people can die in a matter of months.  The US would have the resources to prepare to protect itself from such a future outbreak, but should it.  Tufekci certainly thinks we should.

“This time, we have not just the warning, but also many of the tools we need to fend a pandemic off. We should not wait until it’s too late.”

She may be right, but in demanding politically risky behavior from those in power she should realize that the nation was once before in this exact position.  Leaders at that time chose to follow her advice and it did not end well for anyone.  Michael Lewis recounts the tale in his book The Premonition: A Pandemic Story.

“That story began in 1976.  In March of that year, at the end of the flu season, a handful of soldiers at Fort Dix in New Jersey became ill.  One died.  The CDC gathered samples and found they’d been infected by a new strain of swine flu that appeared to be related to the virus that caused the 1918 pandemic.  The army found that at least five hundred more soldiers had been infected.”

The CDC experts had some experience to fall back on to influence them, plus a vivid knowledge of the havoc caused by the 1918 outbreak.

“They’d detected a pattern: roughly every decade the flu genome found some way to evade the human immune system.  They had predicted the previous genetic shift in the virus, back in 1968, and were expecting the next one soon, and believed it would involve pigs.  The sample size was small—1918, 1957, 1968—but each time a new strain of flu had been identified, it had resulted in a pandemic.  The severity of the disease was an open question, but it felt to the experts a lot like the one back in 1918—when the first outbreaks had also been mild.”

The head of the CDC recommended that the nation prepare to vaccinate its entire population before the next flu season.  Political leaders agreed to follow the CDC’s advice.

“Then just about everything that could go wrong went wrong.  The vaccination program began on October 1, 1976, continued for two and a half months, and reached forty-three million Americans.”

“Two weeks into the program, three elderly people in Pittsburg died.  They’d all been vaccinated at the same clinic.  Their deaths made national television news.  The vaccine fell under new suspicion…A month later a recently vaccinated man in Minnesota was diagnosed with Guillain-Barré syndrome.  Over the next few weeks more cases emerged, until the CDC had counted fifty-four in ten states.  The vaccine was pretty clearly responsible…The vaccine program went from controversial to unpopular to, on December 16, suspended.”

“And the pandemic never came.  The new strain of swine flu simply vanished.  No one knew why.”

According to Lewis’s telling, after this incident, the CDC never recovered the influence and respect, nor the confidence, it once had. 

We must be ready to move quickly when necessary, but it is difficult to see a preemptive strategy emerging from our current political environment.

You can learn a little about a lot of things or you can learn a lot about a very few things. Guess which is the most fun.