This does mean there isn't an inevitability of emergence into humans if people's exposure to the virus is reduced and the measures are taken to stop the spread the cows. Although, the Canadian case has a virus that was previously only detected in birds. - ThreadSky

arambaut.bsky.social • 95 days ago

This does mean there isn't an inevitability of emergence into humans if people's exposure to the virus is reduced and the measures are taken to stop the spread the cows. Although, the Canadian case has a virus that was previously only detected in birds.

Comments

fleishon.bsky.social•95 days ago

I completely agree that everything we're seeing doesn't mean the chance of transmission and pandemic is imminent. Statistically, it would require many more "dice rolls" of the virus. We're might even see a step of terminal branches in humans, without it leading to an epidemic.

fleishon.bsky.social•95 days ago

This doesn't mean the danger isn't significant. In assessing the danger, we must consider not just the probability but also the risk. The risk here is enormous - so even when multiplied by small probabilities, from my POV it should justifies raising warning flags now.

fleishon.bsky.social•95 days ago

The key data is that against this chain of infection in cows, not only are no strong measures being taken, but its continuation is mediated by human activity. And it's not at all clear what will cause a change in this policy.

adamjkucharski.bsky.social•95 days ago

Thanks, realise could have been clearer there. Didn't mean circulating population of viruses in animals is becoming better adapted to humans (given lack of ongoing H2H chains, as you say) - rather, singleton human case detected with a mutation that could potenitally make it better adapted to humans.

adamjkucharski.bsky.social•95 days ago

Have made an edit (with credit)

flodebarre.bsky.social•95 days ago

Also important to note that the BC case is for sure unrelated to the dairy cattle outbreak, because it is a different genotype

arambaut.bsky.social•95 days ago

Better adapted to that human, certainly. Long infections give the virus the opportunity to adapt by evading elicited immunity (or that might be the cause of the long infection). The crux is whether those mutations also (coincidentally) enhance transmission between humans.

arambaut.bsky.social•95 days ago

This is probably the mechanism by which SARS-CoV-2 variant Alpha became more transmissible but it was already very transmissible so that was more of a tweak.

arambaut.bsky.social•95 days ago

That means that long infections provide a greater risk of mutations that enhance transmissibility being acquired, it still just brings us to reducing human exposure as our current best response. And this includes understanding the prevalence and spread in cattle - data that is currently lacking.

Comments

Posting Rules

Reply