On this 100th anniversary of the worst pandemic in recorded history, and the 50th anniversary of the 1968 H3N2 pandemic, it is no surprise that we're hearing a lot of talk about the `next pandemic'.
But it is more than just the calendar that has scientists worried. There are other factors which make another - possibly severe - pandemic increasingly likely.The first is how the world has changed over the past 10 decades. We are now a highly mobile society, with literally millions of international travelers in the air on any given day. While a trip from England to New York City might have taken 5 days (via ocean liner) in 1918, today it can be done in just under 8 hours.
An infected, but pre-symptomatic, international traveler 100 years ago would likely have fallen ill before reaching their destination, while today that passenger would have a very good chance of carrying an incubating virus undetected to almost any corner of the earth.
But it isn't just people being moved, it is farm animals as well.Unlike 50 years ago, pork is no longer a locally produced product of small family farms. Commercial pigs are often mass raised in one region, shipped off to a corn belt' area to be fattened, and often transported again someplace else to be slaughtered.
Internationally, live hogs are often shipped for breeding purposes, to inject genetic diversity into local herds to improve the breed.
And hitching a ride are frequently H1, H2, and H3 swine flu viruses - which, while endemic in pigs around the globe - have significant genetic diversity across the world (see Trans. & Emerg. Dis.: Appearance Of Reassortant European Avian‐origin H1 influenza A viruses in Swine - Vietnam).This move from small farms to large commercial operations has also helped to turn LPAI (low path avian influenza) viruses - which are ubiquitous and largely harmless in wild birds - into HPAI (highly pathogenic) avian flu strains in poultry.
Also, as we've discussed often in the past, we've seen a huge rise in the number of zoonotic emerging diseases, other than influenza. SARS, MERS-CoV, Zika, Ebola, Marburg, SFTS, Nipah, . . . . the list goes on.
For a deeper discussion on why this appears to be happening, you may wish to revisit 2016's The Third Epidemiological Transition,which looks at the work of the late anthropologist and researcher George Armelagos of Emory University.The gist of his theory, however, is that the world has entered into an age of newly emerging infectious diseases, re-emerging diseases and a rise in antimicrobial resistant pathogens.
So far, given the events of the past 40 years, it has been hard to argue against it.And as technology grows, the ability of `bad actors' to create engineered pathogens becomes both easier and cheaper, and no longer requires the deep pockets, security apparatus and expertise of a nation state.
We saw this ominously depicted earlier this month in the Johns Hopkins Clade X exercise, where a genetically altered Nipah virus (spliced onto a parainfluenza backbone) was the cause of their fictional pandemic.All of which brings us to a Perspective Article penned by Bill Gates and published today in NEJM, which looks at the unique pandemic challenges of this 21st century, and some of the innovations (both existing, and under development) which will be needed to combat the next global health crisis.
Follow the link below to read the full article.