How much should we worry about the pneumonic plague lableak in Siberia?

By Drew Spartz @ 2026-10-05T17:42 (+41)

Epistemic status: I wrote this up hoping people can poke holes in it because I am quite worried.

Here's what we've heard so far:

As of Oct 4th:

CleanShot 2026-10-04 at 20.52.02@2x.png

Why this might be a big deal

 

Why this might not be a big deal

10/5 update:

CleanShot 2026-10-05 at 18.24.39@2x.png

 

10/6 update:

Please let me know anything else I'm missing here.


huw @ 2026-10-06T15:56 (+4)

I don’t think you can have it both ways—don’t we want people to freak out and quarantine a bunch of places if a bio facility has an issue like this? Why would this be a sign that the plague is more likely to be really bad, rather than just a sign that we learned the lesson from COVID? (Similarly, border measures are pretty regularly just a political cudgel; see Italy tightening border controls with Spain (??) after the Ceuta breach)

NickLaing @ 2026-10-06T16:22 (+2)

Yep I actually think the current response is close to the best case scenario

1. Russia freaks out properly and do all they can
2. Russia denies everything.

Given geopolitics seems among the best possible outcomes. 

NickLaing @ 2026-10-06T13:49 (+4)

This is an interesting one thanks for raising it. The last time I heard of "Irkutsk" was playing Risk 15 years ago....

If its plague (even a bioengineered one), then I'm not so worried. They would have to make it both more contagious and less treatable for it to be a dangerous global pandemic - achieving both of those would be possible but notoriously difficult. If they managed the contagion piece they could in theory just expose it gradually to all the different common antibiotics to build resistance. This process though would likely make it far less deadly so its not easy. Unless AI has new ways to hard-code resistance :(.

 But even then there would still likely be a range of antibiotics that could treat it effectively. Otherwise if it was regular plague even with increased infectivity we could probably just
1. Wear masks
2. All take dirt cheap prophylactic antibiotics.
3. It's great that far UV has already been installed waiting for activation in all airport lobbies (That is a joke)

Also what are the chances that the virus that escaped is the "contageous + highly deadly" one in particular? We'd have to be pretty unlucky there.

I'm more worried if it was some other bioengineered virus, that could obviously be very very bad.

Minor point, the word "virulence" as a technical term describes how deadly the pathogen is, not how readily it spreads. For that we can say its very contageous, has high infectivity, or transmissability. Its pretty annoying terminology I know but hey...

Also minor point but there's no way regular plague mortality would be above say 5% in an outbreak (still 10x covid). The only big recent outbreak we have was in Madagascar with 2000+ in 2017 cases and mortality rate was 9% there. Would be far far lower with prophylactic and early antibiotics, plus decent access to intensive care.

But completely agree its pretty darn scary with that degree of response... 

Its lucky that with Covid nothing happened too :(

SiobhanBall @ 2026-10-05T18:40 (+3)

Thanks for posting about this; I hadn't heard about it. I chuckled at 'nothing ever happens' and realised how much weight I'm guilty of putting on that when deciding how much to worry about things like this.

But also, it apparently has a short incubation period of 1-3 days. I reckon if 200 close contacts were exposed and there are still no secondary symptomatic cases in a week from now, then we can be at ease on this particular GCR. 

Drew Spartz @ 2026-10-05T19:58 (+4)

Evidence points toward there being more cases. 5 hospitals are quarantined, and other countries are increasing quarantine / sickness checks at the border. If there were no other cases, I would doubt that the Russian government would be attempting as much of a cover-up as they are right now.

SiobhanBall @ 2026-10-05T20:12 (+4)

I hope those measures are precautionary only. If there is a cover-up, it doesn’t seem to be going well. 

huw @ 2026-10-06T15:58 (+2)

Obligatory Metaculus link for following this