This is a special post for quick takes by Rachel Shu. Only they can create top-level comments. Comments here also appear on the Quick Takes page and All Posts page.
Preliminary thoughts on MPOX 1b:
Most recent WHO report: https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox--external-situation-report-35--12-august-2024
Released every other week so next one due in a day or two.
Agree with medical consensus that lockdown-qualifying global pandemic still seems unlikely, but I am concerned enough. I'm guessing <10% chance of global pandemic, <1% chance the median LessWronger gets infected, including tail risk (as in I don't think that even 10% of Westerners get infected even if it becomes a global pandemic.) Nonsexual transmission is more likely this time around than 2022 but sex parties still seem like a key locus. If you intend to go to sex parties in the next 3-4 months you should get the Jynneos vaccine soon, as it takes 2 doses, and there is some chance of a temporary supply shortage.
Things to worry about:
Presymptomatic transmission seems likely.
This is more deadly, and higher transmission, than 2022's MPOX Clade 1I outbreak. 3-5% death rate, more severe among children than adults (opposite of COVID). Unfortunately kids also tend to be in closer proximity to each other than adults.
Less clearly associated with sexual contact than 2022, good evidence of nonsexual skin-skin transmission being prevalent.
Some possible reported cases of reinfection in people who previously had MPOX (I can't track this down)
Virus is already being reported in non-endemic countries. No person-to-person contact in the West yet, but seems probable in the near future.
People vaccinated for smallpox a long time ago have probably lost their immunity by now.
Reasons to not worry:
Not a zero-day exploit like COVID was, we already have several proven, reasonably effective vaccines and a process for delivering them, and a decent number of previously vaccinated people. I haven't looked into supply constraints on vaccine production, and naively expect production to scale well.
No stupid refusal to test potential cases this time
Probable cross-protection from 2022 outbreak (given that the vaccine is made from an even more distant virus and is protective)
A lot of potential superspreaders (assuming sex parties are still a large component of the risk of superspreading) are already vaccinated/recovered, at least in the US.
Aerosol or droplet transmission isn't likely, and the limited evidence we currently have suggests that we're still looking at skin-skin contact transmission as with MPOX Clade 1I. However, smallpox was primarily droplet-transmitted (with some evidence for aerosol transmission) so it's not out of the realm of possibility. <Of course, that's what we said with COVID too.>
Random other things I've learned or thought about:
After the point at which droplet transmission is established, it seems like co-infection with other, more cough-inducing respiratory diseases is an underexplored risk factor for superspreading, but that's not super common.
Shedded smallpox scabs were not very infectious. Surface-based transmission was most likely during periods peak illness, when it was very obvious that it was smallpox and people knew to stay away.