#17,279
When I began this humble blog 17+ years ago, H5N1 was raging in Southeast Asia and had only recently arrived in Europe, and many feared a bird flu pandemic was imminent.
Since then H5N1 has evolved into multiple clades and subtypes (H5N1, H5N2, H5N6, H5N8, etc.), some more dangerous than others, and has spread globally.
While we've seen several large outbreaks over the years (see FAO: Egypt’s H5N1 Case Count Continues To Climb) - and occasional spillovers into other mammals (see HPAI H5: Catch As Cats Can) - the virus has never managed to adapt well enough to humans to spark a pandemic.
There are even some experts who suspect H5 flu viruses may be incapable of making that leap (see Are Influenza Pandemic Viruses Members Of An Exclusive Club?). But then, the same could have been said about coronaviruses not so many years ago.
After several years of decline early in the last decade, H5Nx reassorted into a more formidable virus in 2016 and sparked a huge epizootic in Europe. Since then it has expanded its geographic and host ranges, raising once again concerns that it might spark a pandemic.
In truth, no one knows what happens next. We've seemingly been on the brink before, only for the threat to lose momentum and then recede. That could certainly happen again.
But an H5N1 pandemic has the potential to be worse than COVID, and its recent unsupervised field experiments in mammals has many scientists legitimately concerned. Yesterday (Feb 8th) the WHO Director-General, in his opening remarks at a media briefing, had this to say about the current threat from H5N1.
Over the past few weeks there have been several reports of mammals including minks, otters, foxes and sea lions having been infected with H5N1 avian influenza.
H5N1 has spread widely in wild birds and poultry for 25 years, but the recent spillover to mammals needs to be monitored closely.
For the moment, WHO assesses the risk to humans as low.
Since H5N1 first emerged in 1996 we have only seen rare and non-sustained transmission of H5N1 to and between humans.
But we cannot assume that will remain the case, and we must prepare for any change in the status quo.
As always, people are advised not to touch or collect dead or sick wild animals, but to report them to the local authorities.
WHO is working with national authorities and partners to monitor the situation closely, and to study cases of H5N1 infection in humans when they occur.
WHO’s global laboratory network, the Global Influenza Surveillance and Response System, identifies and monitors strains of circulating influenza viruses, and provides advice to countries on their risk to human health and available treatment or control measures.
WHO recommends countries strengthen surveillance in settings where humans and farmed or wild animals interact.
WHO is also continuing to engage with manufacturers to make sure that if needed, supplies of vaccines and antivirals would be available for global use.
While it isn't clear when, or even if H5N1 will evolve into a pandemic virus, we do know that it isn't the only threat we face. The following graphic from a recent UK HAIRS report illustrates the rising number of infectious disease threats around the globe over the past 20 years.
Credit UK HAIRS
Granted, we might go years, or even decades, before the next severe pandemic arrives - but it could just as easily emerge tomorrow.
Despite all of this our global disease surveillance and reporting network continues to erode (see Flying Blind In The Viral Storm), and governments, businesses and individuals do very little to prepare for the next one.
Sixteen years ago, in a blog called `Quotable Quotes', I listed more than a dozen pandemic warnings from world leaders, scientists, and public Health and Safety officials. After 3 years of COVID, none ring truer today than:
Everything you say in advance of a pandemic seems alarmist. Anything you’ve done after it starts is inadequate.
- Michael Leavitt, Secretary of HHS
