Marek vaccine shedding

[Iluveggers]

So is it safe to put my home hatchlings (unvaccinated) in with the vaccinated ordered chicks that will arrive in the mail within days of my planned hatch?

 

[Wyorp Rock]

The reason for this is that a flock of vaccinated birds that can survive a deadly strain will nevertheless act as long-term hosts, forever shedding that more deadly strain into the environment once they’ve caught it. This has nothing to do with the vaccine itself shedding, it just means more potential hosts to transmit whatever hellish version might already exist in the environment.

And that's a good thing?

 

[FlarryEyeGrey]

And that's a good thing?

Good for the keeper who’s not picking up bodies every morning, not so good for the keepers who free range or otherwise aren’t practicing much biosecurity in a badly impacted area and have unvaccinated birds.

 

[FlarryEyeGrey]

So is it safe to put my home hatchlings (unvaccinated) in with the vaccinated ordered chicks that will arrive in the mail within days of my planned hatch?

Yes, that is the safest scenario with a mixed vaccinated/unvaccinated flock. The risk calculation changes slightly if you have a mature flock of vaccinated birds with confirmed Marek’s, because any unvaccinated chicks you added in would be getting a very high viral load as soon as they were exposed to the mature birds. Raising them all together at around the same age is unlikely to increase the risk for the unvaccinated birds even if the whole flock is exposed later in life.

 

[Iluveggers]

Yes, that is the safest scenario with a mixed vaccinated/unvaccinated flock. The risk calculation changes slightly if you have a mature flock of vaccinated birds with confirmed Marek’s, because any unvaccinated chicks you added in would be getting a very high viral load as soon as they were exposed to the mature birds. Raising them all together at around the same age is unlikely to increase the risk for the unvaccinated birds even if the whole flock is exposed later in life.

Thank you! Super helpful!

 

[lisa69]

For what it’s worth, I just started vaccinating my home-incubated chicks myself as I recently had a few cases of suspected Marek’s in my flock. My understanding is that all of the available vaccines use live virus (a few different strains), so shedding can definitely be expected. However, the reason these strains are safe to use in the first place is that they’re not very pathogenic at all. If you can inject the vaccine strain directly into a day-old chick, it’s not going to kill the bird next door who catches it via shedding, and may even be protective if that bird hasn’t already been exposed to a natural strain.

A separate issue that may be getting conflated here is that the widespread use of these vaccines may be making other strains of Marek’s more deadly. The reason for this is that a flock of vaccinated birds that can survive a deadly strain will nevertheless act as long-term hosts, forever shedding that more deadly strain into the environment once they’ve caught it. This has nothing to do with the vaccine itself shedding, it just means more potential hosts to transmit whatever hellish version might already exist in the environment.

Amen well said. I stuck myself too Lol. I was nervous . It is a herpes Viris.