Can SARS-CoV-2 Successfully Cross Species to Infect Deer Populations?

[Jarvis323]

We've known that Sars-Cov-2 can be transmitted from humans to a wide range of animals. Now we are learning that it has widely spread through deer populations.

Up to a third of deer in Iowa had recently been infected by SARS-CoV-2, according to one estimate.​

https://gizmodo.com/uh-oh-the-coronavirus-has-been-spreading-widely-in-u-s-1847999600

Have we ever observed this kind of thing playout? Do we have any idea what to expect in the long term?

 

[Drakkith]

Have we ever observed this kind of thing playout?

Yes, influenza variants do this all the time.

Do we have any idea what to expect in the long term?

To guess, I'd say we can expect the virus to be with us a long, long time, possibly mutating into different variants that may or may not be infectious towards humans.

 

[pinball1970]

We've known that Sars-Cov-2 can be transmitted from humans to a wide range of animals. Now we are learning that it has widely spread through deer populations.
https://gizmodo.com/uh-oh-the-coronavirus-has-been-spreading-widely-in-u-s-1847999600

Have we ever observed this kind of thing playout? Do we have any idea what to expect in the long term?

Looking at some of the big killers in terms of animal reservoir.

There is a reservoir of Ebola virus in African (mainly), Bats and some primates that cause regular outbreaks in humans.

Infected bats eat fruit that transmits to other animals and the bats are hunted by humans and cured (looking at the images) which may not kill the virus.

Once a human is infected the virus spreads via bodily fluids, % different genomes, I suppose these mutate and become more or less infectious over time?

https://en.wikipedia.org/wiki/Ebola#Reservoir

TB and Malaria are human reservoir only

HIV mainly human but this thought to have jumped from primates initially.

I suppose all it takes is a favourable mutation to the virus whichever host species it happens to be in, then an opportunity to “jump”

Some viruses just need a chance to jump, we are already suitable hosts.

 

[BillTre]

Many diseases can transmit between humans and other animals.
Covid can also infect various cat species and ferrets.

When I was running zebrafish facilities, we became aware of two difficult to eliminate, endemic diseases that were zoonotic (could transmit to humans from fish).
One was a mycobacteria, called fish tuberculosis, but more closely related to leprosy.
The other was a microsporidia, an infectious cell that lives inside of zebrafish (or other) cells
We also once found, in a molecular survey, a vibrio that was indistinguishable from cholera in our zebrafish, but it lacked a virulence factor. Losing the virulence factor is one of the ways cholera adapts to conditions with better sanitation by making people less sick.

The Chytrid fungus, also known as Batrachochytrium dendrobatidis, is spreading wildly between many frog species in the wild and killing them off. It also develops a reservoir in crayfish in the frog habitat, making it almost impossible to eliminate. Frogs put back in where the frogs have all been killed off still get infected even though all the frog hosts have been killed.

Many pathogens are promiscuous.
It is not a surprise.

 

[jim mcnamara]

Influenza genetic changes are monitored by sampling wild mallard ducks in Asia and North America.
Spillover is the term in common usage for zoonotic events.

Here is one version how the Influenza->/duck/duck/pig/->human spillover thing works...

1. Huge reservoir of influenza genotypes resides in wild ducks.
2. Wild ducks poop into ponds where farmers have domestic ducks.
3. Domestic ducks dabble in the pond, pick up the novel virus from the bottom.
4. Domestic ducks spend the night in a shed near the pig pen.
5. Some of the domestic duck poop gets into the pig pen.
6. Pigs get influenza.
7. Humans butcher pigs.
8. Humans get brand new viral genes and spread them worldwide.

Look up how BSL certification is enforced for safely doing laboratory research on virus:
https://www.phe.gov/s3/BioriskManagement/biocontainment/Pages/BSL-Requirements.aspx

Examples:
Ebola research requires an expensive BSL-4 lab and extensive training, Covid-19 requires requires a BSL-3 minimum lab. This is why research using live or attenuated virus is not a simple backyard shed experiment.

 

[symbolipoint]

We've known that Sars-Cov-2 can be transmitted from humans to a wide range of animals. Now we are learning that it has widely spread through deer populations.
https://gizmodo.com/uh-oh-the-coronavirus-has-been-spreading-widely-in-u-s-1847999600

Have we ever observed this kind of thing playout? Do we have any idea what to expect in the long term?

Can those deer be all or nearly all vaccinated?
Can those deer be mandated to wear masks while foraging or wandering in groups?

(relax; just joking)
(excuse me; this is not something to joke about)

 

[Drakkith]

Can those deer be all or nearly all vaccinated?
Can those deer be mandated to wear masks while foraging or wandering in groups?

(relax; just joking)
(excuse me; this is not something to joke about)

Oh deer...

 

[Jarvis323]

Can those deer be all or nearly all vaccinated?
Can those deer be mandated to wear masks while foraging or wandering in groups?

(relax; just joking)
(excuse me; this is not something to joke about)

Maybe the vaccine can be delivered through mosquitos?

https://www.science.org/content/article/researchers-turn-mosquitoes-flying-vaccinators

Eventually tiny autonomous drones could be deployed. Just vaccinate anything that moves to be safe.

 

[BillTre]

Maybe the vaccine can be delivered through mosquitos?

https://www.science.org/content/article/researchers-turn-mosquitoes-flying-vaccinators

Eventually tiny autonomous drones could be deployed. Just vaccinate anything that moves to be safe.

Mosquitos as vaccine vectors, possible.
Mini autonomous drones not plausible in the current technical era.

 

[symbolipoint]

Mosquitos as vaccine vectors, possible.
Mini autonomous drones not plausible in the current technical era.

From a couple of attempts at humor to some interesting ideas. Question to find answer to , is would the vaccine be at a high enough dose and be stable while being carried in the mosquito? My guess would be "no". Other scientists may know better.

 

[symbolipoint]

Mosquitos as vaccine vectors, possible.
Mini autonomous drones not plausible in the current technical era.

Right now I can not imagine how a mosquito could carry and deliver and inject a vaccine. And then, how to load the vaccine into the mosquito?

 

[BillTre]

Well hypothetically a mosquito could be loaded (infected) with a virus that would infect cells of the person it bites (similar to infections with zika or a bunch of other diseases). The virus would have to be engineered so that the cells of the infected person would express the piece of the spike protein like current viruses do.
Not yet current biology, but not completely beyond technical feasibility, unlike mini autonomous drones.

 

[Jarvis323]

Right now I can not imagine how a mosquito could carry and deliver and inject a vaccine. And then, how to load the vaccine into the mosquito?

The article appears to says that they genetically engineered mosquitos to produce the vaccine in their saliva.

A group by led by molecular geneticist Shigeto Yoshida of Jichi Medical University in Tochigi, Japan, identified a region in the genome of Anopheles stephensi-a malaria mosquito-called a promoter that turns on genes only in the insects' saliva. To this promoter they attached SP15, a candidate vaccine against leishmaniasis, a parasitic disease spread by sand flies that can cause skin sores and organ damage. Sure enough, the mosquitoes produced SP15 in their saliva, the team reports in the current issue of Insect Molecular Biology.

https://www.science.org/content/article/researchers-turn-mosquitoes-flying-vaccinators

I didn't really post this as a serious suggestion for Sars-Cov-2. Vaccinating an animal population like this might do more harm than good. Because the vaccine would only be partially effective (even at an optimal does, but the dosage through mosquito saliva would be variable), and so my guess is that all you could really hope to achieve is putting a little bit of evolutionary pressure on the virus, and saving some lives within the deer population.

This might result in the virus finding new mechanisms to infect the vaccinated hosts (rendering the vaccine less effective), or even anti-body dependent enhancement. This occurring in the animal population would only bring greater risk to the human population I would think.

It would be a different story if a vaccine given to the deer through mosquitos were much more effective, and able to eradicate the disease. Maybe that could be possible in the future. But even then, I think it would be irresponsible, because you can't be precise using mosquitos to deliver the vaccine. It might not work as expected. It would also affect other animals, and people, and set a precedent that crosses a line in my opinion.

 

[BillTre]

The autonomous part is what I don't think is possible.
Of course that has several possible layers of distinction concerning autonomy.

Autonomous like a mosquito, would mean being able to at least have power for extended periods of time (battery life for a drone limits its life.
Mosquitos already have a highly evolved hunt and bit routine built into their very small and highly efficient little brain. No connection to a central server required. Which seems not autonomous to me.
Mosquitos would not have to stay within range of contact with the central server. Nor would the deer.
The mosquitos would probably be created in a lab (by breeding and inoculating with the virus), but it would be much cheaper than making an equivalent number of drones.

Only female mosquitos bite, so they would be the ones to use for infection purposes. Their biting would also be a refueling stop, so they could proceed to bite some more (rather than recharge their batteries or crash.

Alternative biting insects to consider might include deer flies (much bigger), which are known to bite deer. However, mosquitos are probably the biting insect, that bites deer, with the best worked procedures for this.

Its not uncommon for people underestimate the highly evolved abilities of biological organisms.
Replicating many abilities of biological organisms is largely beyond current engineering, but a worthy endeavour nevertheless.

 

[Laroxe]

Its not as easy as people may think for a virus to jump species, often the biggest hurdle is in developing the ability to be transmitted in the new hosts. The Coronavirus that causes MERS hasn't achieved this, each new outbreak reflects infections from their natural hosts (camels). To cross species the virus has to be able to gain entry to cells and then multiply, this often involves some significant changes in their genome, they often pick up these changes when an animal becomes infected with two different viruses and genetic re-assortment occurs. It may be more likely in animals with impaired immune function. Then of course the original host and the new hosts must share some important physiological features, in the case of Covid 19 a ACE 2 receptor with similar features to the human receptor would be needed.
I do know that pet dogs are offered the Covid vaccine as part of the routine booster vaccinations, but the stuff about mosquitoes makes me think that this would need to involve a live attenuated virus so that the vaccine persists in the mossy population. The recent findings in relation to the polio virus in which the attenuated vaccine virus re-established its ability to spread and cause disease would seem to be considered a high risk intervention. It now appears that the plan to eradicate polio can't possibly work. Then as the vaccines appear to offer little advantage in stopping transmission, waiting for natural exposure to increase immunity might be the best option. An oral vaccine, delivered by spreading bait, which they already do with badgers, might work.