Marc Johnson Profile picture
May 4 9 tweets 2 min read Read on X
A few points about the H5N1 outbreak that I'd like to share.

1. If we had a pan-influenza wastewater screen in place nationally that differentiates the influenza sources by sequencing (which isn't that hard to do), we probably would have detected this outbreak months ago.
1/
BTW, we submitted a CDC proposal earlier this year to do exactly this, but the topic was pulled from the BAA so the proposal wasn't even reviewed.
2/
2. We should not panic about the current outbreak in cattle. You aren't going to get influenza from pasteurized milk, and this virus isn't ready for human-to-human spread (yet).
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3. What we should be concerned about is that fact that the viruses is getting way too many chances. It keeps expanding its tropism. The more animals it replicates in, the more chances it gets to sample new configurations.
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4. When the virus makes it way it to pigs, that is when we need to start getting really nervous. Pigs are a mixing vessel where flu is more likely to adapt to respiratory spread in humans.
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5. In my opinion we should be focusing our attention on wastewater testing downstream of meat processing plants (for all types of animals). It wouldn't matter what tissue the virus is in, it would end up in the water and give us an early warning.
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We've detected and sequenced pig influenza from such sewersheds before (not H5N1), so I know it can work.
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6. Most important, we shouldn't shy away from surveillance because we want to avoid a panic. There is still time to stay ahead of this, but if we aren't careful I think it's just a matter of time before H5N1 makes it to humans.
8/8
4.

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More from @SolidEvidence

Nov 14
I knew there were a lot of fake accounts on this platform, but they are usually obvious. I had no idea how intricate and complex the ruse could be.

Get a load of this story.
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About a week ago I got a DM from an account asking me a benign but specific question about my research.

This happens to me all the time. I’ve met some interesting people this way.

Sometimes people even look up my number and call my office. It happens.
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The account looked legitimate. They are a paying account (I’ve never seen a bot that pays).
They’ve been on the platform for over 2 years.
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I'm doubling down on MV.1*

This lineage has been growing rapidly recently, but it's been hard to tell if it would be a real contender since most of the infections were from Singapore.

In North America its growth has been more questionable.

But I have new data.
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You probably know that our team screens all of the wastewater sequences submitted to SRA for cryptic lineages.

One of the 'cryptic-specific' changes we look for is S:F456V, which is common in cryptic, but hadn't been seen much in circulation until recently.
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MV.1* has a reversion at S:478 back to T, which is right next door to 456V, so its easy for me to check if the 456V sequences are in fact MV.1*

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Read 5 tweets
Oct 28
Cryptic lineage quarterly update, last update for now.

I save the weirdest for last. Read to the end.
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The sample was from 9/30 in Texas. Population is 780, so it isn’t even on the NWSS map.

I don’t know where the sample was from.
2/ Image
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Very weird.
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Read 9 tweets
Oct 26
Cryptic lineage quarterly update, part 3
Cleveland variant.
If you missed part 1 and 2, they are here.
x.com/SolidEvidence/…
x.com/SolidEvidence/…
1/
My favorite way of finding cryptic lineages by screening for what I call the ‘s2m fix’.
s2m is an RNA element at the end of the SC2 genome that has been deleted from all lineages in circulation for over 2 years.
If you see the s2m sequence, you know it is an old lineage.

2/
A distinctive thing about cryptic lineages is about a third of the time they pick up a very specific mutation in their s2m sequence. T29758G. It’s actually a reversion to the sequence found in bats.

More about s2m here, if you are interested.


3/
Read 11 tweets
Oct 23
Cryptic lineage quarterly update, part 2
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If you missed part 1, it is here.

1/
BA.1 cryptics. BA.1 infections all occurred in late 2021-early 2022. If there is good coverage, BA.1 lineages are easy to spot because they have a unique Spike insertion that no other lineages have had.
2/ Image
There were hints of a few BA.1 lineages across the country, but there were only 2 that were really clear, one in San Diego and one in Western Colorado.
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Read 12 tweets
Oct 22
Cryptic lineage quarterly update, part 1
Recent BA.2-XBB cryptics

Cryptic lineages are unique, evolutionarily advanced SARS-CoV-2 lineages detected from wastewater from an unknown source.

1/ Image
We are almost certain that these lineages are derived from individuals that have been infected with SARS-CoV-2 for several years that are shedding a ton of viral material.

If you want to know why we think these are from humans, read this thread.

2/
Or read our paper on the lineage we almost tracked down.

3/
sciencedirect.com/science/articl…
Read 14 tweets

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