Of Chicks and Men--Marek's Virus Vs. China Virus

a reply to: nonspecific
Honestly, the study in the OP was a bit heavy on speculation. The source in the PBS article states:

Our data do not demonstrate that vaccination was responsible for the evolution of hyperpathogenic strains of MDV, and we may never know for sure why they evolved in the first place.

Even they couldn't really pin it on the vax, but it seems like something dug up that can fit an argument some people want to make.

a reply to: nonspecific
You have chickens don't you..... several hundred if I remember correctly.

Do you have to vaccine every one of your chickens?

Why not try experimenting yourself?
Don't vaccinate a chicken and let us know what happens.

Didn't you also say:

I guess whatever went wrong wasn't enough of an issue to rectify as they just vaccinate all the new chicks anyways.

I'm not going to comment on the reasoning behind the post.

It does show though that as more research is done things can change.

The outlook in 2015 was quite different to the one I posted about five years later.


a reply to: daskakik

I don't vaccinate any of my chickens for mareks.



a reply to: Itisnowagain

originally posted by: jefwane
I think the Marek's disease outcome is unlikely as long as there remains a sizeable unvaccinated cohort that develops natural immunity.

How does natural immunity differ from the vax in these chickens?

I mean it is a "real" vaccine with a real but dead virus.

What was posited in the OP is that all vaccines might end up facilitating deadlier viruses, but there is no reason why natural immunity wouldn't do the same thing, it is the same mechanism.

a reply to: nonspecific

Leakiness allows pathogen populations to persist even at high levels of vaccination coverage [4], and reduced mortality of vaccinated individuals can lengthen their infectious period and hence promote the evolution of increased pathogen virulence [5]. A better understanding of the overall impacts on populations of vaccination with leaky vaccines is therefore urgently needed.

This is from one of your links.
And this:

However, from the 1950s to the present day, there have been several jumps in MDV virulence [34], each causing more severe symptoms and reducing the symptom-blocking effects of existing vaccines. Several generations of vaccines have been developed to combat this increased virulence, all of which are leaky and may in fact have contributed to continuing virulence evolution.

a reply to: nonspecific
I think you took that the wrong way, maybe.

I'm seeing what you are seeing, an older study and a contradicting newer study.

What I pointed out was that the older study included a caveat, because they were not sure what caused the change in the virus.

I'm not sure what your point is with this?

A virus will mutate regardless of vaccinations or not as you know.

Is there a direct causation between the vaccine and the mutation that has been established or is it just suggested that the vaccine can allow infected birds to remain alive longer and therefore shed more virus over the course of its life?



a reply to: Itisnowagain

a reply to: nonspecific
There is a really informative podcast with Dr Andrew Read that you can listen to:

The Evolution of Virulence with Andrew Read
asm.org...

This is from the link:

Vaccination inhibits strains with lower virulence more than strains with higher virulence. This fact, combined with asymptomatic infection, means that although the infected birds don’t show disease symptoms, they are more likely to be shedding more virulent (or ‘hot’) strains. This generates selection for these hot strains that wouldn’t normally be successful. Without vaccination, host strains kill the host too quickly to allow viral replication and transmission to occur; Vaccines allow these hot strains to propagate.

But on the other hand vaccinated birds shed a lower viral load.

Mareks was already a very serious problem, that's the reason the vaccine was created in the first place.

It's not really something we can discuss without it becoming circular and I personally feel its relation to the covid 19 virus and vaccines is not relavant enough to warrant any more analysis.


a reply to: Itisnowagain

a reply to: nonspecific

I have something to do with animals in my job. No there is not a direct link between the vaccine and the mutation. But it was strongly suspected because the mutations became more deadly after the vaccine was introduced. Birds vaccinated against Marek actually shed more virus than unvaccinated birds. Like way more.

a reply to: nonspecific

The real difficulty is that the COVID data is just garbage. I say this as a statistician and analyst...the data is garbage. And the more i find out about it, the worse it seems.

The PCR is the real issue, and the watery way in which it was utilized and interpreted (changing tolerances, etc).

I say that to set up this statement: COVID likely was not deadly on any scale beyond its novel infectious nature playing a numbers game.

To analyze whether getting the COVID vaccine is a reasonable thing to do really does require us having good information to inform that decision.

On that alone, i'd say that the comparison to Mareks is devalued. Outside the lesson learned from deploying it, and what it resulted in.

It feels that science wanted to make this vaccine to push forward with mrna vaccines for the sake of cancer research. And it feels that governments were willing to go along out of fear of reduced populations crumbling economies. The people in charge are also heavily invested in markets that require constant growth.

a reply to: Itisnowagain

Question. Marek's vaccine is leaky and bad, because it keeps infected chickens alive.

So are you suggesting a vaccine that keeps infected people alive is bad?

Mareks is only a real concern in industrial farming. Welfare and hygiene along with general bird wellbeing plays a large part in mortality with mareks.

It's a leaky vaccine but it works far better than no vaccine at all, it's business at the end of the day and a business won't pay for a vaccine that won't give a decent return on investment will it.



a reply to: OccamsRazor04

a reply to: OccamsRazor04

You are posing 2 different questions. Humans and chickens, from the perspective of humans, have 2 vastly different scales of value. Chickens have value that is nutritional and economic in nature...humans generally do not (or should not).

In a scenario where we are talking about taking steps that make infectious disease more likely to find human hosts, or have worse symptoms, is better measured through the notion of having empathy with future humans. This vaccine isn't the only scenario to consider. Our use of antimicrobials seems to be having a negative effect on preventing superbugs.

a reply to: bigfatfurrytexan

The problem with Marek's vaccine being leaky is that the chickens don't die if vaccinated, and them being alive allows them to spread the infection for a longer time. Unvaccinated chickens who then get it from a vaccinated chicken (who should be dead and not contagious) will then die.

So the comparison between the two is only viable if we assume covid will kill it's host, but them living means they are contagious longer. So if people are not being saved, there is no comparison.

Data shows vaccinated people have almost no risk of contracting most forms of covid, and the variants they do contract they have a shorter and milder illness. That means less chance for mutations. The variants that infect the vaccinated also evade immunity gained from a previous infection, so there is no scenario I can think of where vaccination is causing more mutations.

a reply to: nonspecific

Helluva coincidence don't you think?

Decades of studies show mareks vaccines made the virus ultra deadly to non-vaccinated chickens. Then in 2020 suddenly that's not the case anymore?

Reminds me of masks. Decades of studies showed they were useless at stopping the spread of viruses. Then in 2020 suddenly they're the holy grail and you should be slaughtered if you don't wear one.

I just throw out almost all of the medical science of the last year if it goes against the prior decades worth of studies. Maybe it's right and subsequent studies will confirm it. But for now, I just don't trust that it's not just politics in science.

It's a commercial product.

Why would chicken farms pay a lot of money for something that did not increase profits.

Chickens don't need a passport to go shopping do they?



a reply to: Dfairlite

a reply to: Dfairlite

Masks are actually great at stopping most virus and decades of research prove it. What do you think healthcare workers wear when working with influenza patients?

a reply to: OccamsRazor04

Please share this research. I've yet to see any of it. Of the masking studies I've seen they all either proved masks were useless or they were inconclusive about the effects the mask had.