[mercy_dude]

I am curious how we are going about studying these in Macaques. Are we trying to deliberately get them the virus and see how their brain respond? If so, haven’t we learned enough on how virus jumps species and can wreck havoc?

[MKRNYILGLD]

The idea is that the monkeys are being used as a 'model organism' for how humans react to getting the virus. Since it is not possible (typically) to extract brain tissue from living humans during Covid infection and see how it's affecting their brain. So macaques are used as a stand-in.

I believe the macaques are just infected with the same Covid strain that can infect humans.

[kadoban]

I'm going to go out on a limb and suggest that covid has already made its way to humans, and doesn't need to jump from monkeys.

[pedalpete]

Doesn't that assume that it had already jumped to monkeys from humans, or from bat to monkey to human?

I have no idea how the process works, and if it easier for a disease to jump from primate to human or vice-versa than it is from other species.

[Tagbert]

The original comment was that there is no risk of Covid in Macaques jumping to humans since Covid is already in the human population.

In general it is probably easier for a virus to jump between closely related species that it is to jump between more divergent species. Humans and macaques only split about 20-30 million years ago. Humans and bat probably split 70 million years ago. It doesn’t mean that bat viruses can’t make the jump, many do, just that it might be harder for them to establish themselves in humans. Bats live in very tight quarters and end up exchanging a lot of virus between each other. This is a great breeding ground for viruses so there are probably more virus types in bats than in many other animals. That gives a large pool of viruses which have the potential to infect humans.