Michael Worobey

Viruses. Pandemics. Professor and Head of Ecology and Evolutionary Biology at the University of Arizona. Tweets mine.

[Michael Worobey @MichaelWorobey]

Here's a visual of the US H5N1 "Cattle clade", HA plus two internal genes.

Strongly suggests to me there was single origin, at least for these sequences.

Possibly in late 2023/early 2024.

[Michael Worobey @MichaelWorobey]

Hi all - I've a couple positions open for lab management and research! Please pass on to creative and enthusiastic folks who might be interested. And repost if you don't mind.

Ability to learn/adapt more important than specific skills!

Thanks so much.

https://t.co/8aT2bdyySh

[Michael Worobey @MichaelWorobey]

@PeacockFlu here provides a really nice summary of our recent findings about transmission of H5N1 in cattle -- and, upstream of this, the best summary of the lead-up to the outbreak.

[Michael Worobey @MichaelWorobey]

Excellent summary of our findings from @ejustin46!

[Emmanuel @ejustin46]

𝗛5𝗡1 𝗟𝗔𝗦𝗧 𝗨𝗣𝗗𝗔𝗧𝗘 !
(🧵 𝘗𝘈𝘙𝘛 1)
"𝘗𝘳𝘦𝘭𝘪𝘮𝘪𝘯𝘢𝘳𝘺 𝘳𝘦𝘱𝘰𝘳𝘵 𝘰𝘯 𝘨𝘦𝘯𝘰𝘮𝘪𝘤 𝘦𝘱𝘪𝘥𝘦𝘮𝘪𝘰𝘭𝘰𝘨𝘺 𝘰𝘧 𝘵𝘩𝘦 2024 𝘏5𝘕1 𝘪𝘯𝘧𝘭𝘶𝘦𝘯𝘻𝘢 𝘈 𝘷𝘪𝘳𝘶𝘴 𝘰𝘶𝘵𝘣𝘳𝘦𝘢𝘬 𝘪𝘯 𝘜.𝘚. 𝘤𝘢𝘵𝘵𝘭𝘦 (𝘱𝘢𝘳𝘵 1)"

[Michael Worobey @MichaelWorobey]

For a report on our analyses of #H5N1 in cattle, see
worobey bsky social

[Michael Worobey @MichaelWorobey]

Tom Peacock, Oliver Pybus, Andrew Rambaut, Angela Rasmussen, Christopher Ruis, Lorena Mariana Malpica Serrano, Marc Suchard, Joel Wertheim, Michael Worobey

[Michael Worobey @MichaelWorobey]

My colleagues and I have just posted a
"Note about availability of #H5N1 2.3.4.4b consensus sequences from cattle and other species" @virological_org.

Consensus genomes and metadata.

https://t.co/ggfgW4FPYa

[Michael Worobey @MichaelWorobey]

Karthik Gangavarapu, Jonathan Pekar, Florence Débarre, Kristian Andersen, Gytis Dudas, Daniel Goldhill, Joseph Hughes, Xiang Ji, Jeffrey Joy, Moritz Kraemer, Philippe Lemey, Louise Moncla, Martha Nelson, Stuart Neil,

[Dr. Angela Rasmussen @angie_rasmussen]

As usual, a great summary of the H5N1 situation by @LaurenPelley @CBCNews, including interviews with colleagues at the forefront of the research including @MichaelWorobey, @SMubareka, & @DuckSwabber. And me.

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

OK, I think we're close to decisive evidence that US bovine H5N1 had a single origin from birds, and that when related viruses from birds *have* been found, they are jumps from cattle back into birds.

Grackles, blackbirds, chickens all show mammalian adaptation like PB2 M631L.

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

So, *preliminary* molecular clock analyses indicate that the time of the most recent common ancestor (TMRCA) of the US cattle flu clade was late December.

TMRCA of that clade and the closest relatives in birds, mid-December.

If single intro, likely between those rough dates.

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

A few thoughts on the role of pigs in the emergence of influenza A virus in mammals.

1. It is simply not the case that movement of flu viruses into non-swine mammal species requires pigs as a "mixing vessel".

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

Into the weeds:

One reason it is particularly frustrating that full metadata has not been shared for genome sequences my colleagues and I have assembled from raw sequence read data released by @USDA / @USDA_APHIS, is that without those dates...

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

We need to talk about that human case of H5N1 in Texas...

Here is a bootstrapped (NJ) tree showing how the closest realtive of H5N1 sampled in cattle is a virus the infected an male individual who reportedly worked on a farm with cattle (dairy, I believe).

[Michael Worobey @MichaelWorobey]

#H5N1

[Michael Worobey @MichaelWorobey]

Here's a visual of the US H5N1 "Cattle clade", HA plus two internal genes.

Strongly suggests to me there was single origin, at least for these sequences.

Possibly in late 2023/early 2024.

[Michael Worobey @MichaelWorobey]

@influenzal #H5N1

[Michael Worobey @MichaelWorobey]

We need to talk about that human case of H5N1 in Texas...

Here is a bootstrapped (NJ) tree showing how the closest realtive of H5N1 sampled in cattle is a virus the infected an male individual who reportedly worked on a farm with cattle (dairy, I believe).

[Michael Worobey @MichaelWorobey]

@influenzal And more complex scenarios exist. Joel Wertheim and I have noticed that the Texas human H5N1 virus might be a reassortant. Its HA, PB2, and NP all appear to sit basal to the current sample of cattle H5N1, while the other 5 segments appear to sit within the cattle clade.

[Michael Worobey @MichaelWorobey]

@PeacockFlu @statnews And cattle/bird/cat/environmental samples from the farm where the Texas human H5N1 case worked.