Do feed stores generally order vaccinated chicks (marek's)? Should I?

[TheFarm41]

I can't speak for every vaccine out there, an I'm not a vet ... disclaimers aside, I don't think you can introduce Marek's from vaccination. That would make no sense ... think about it ... you would "vaccinate" by injecting the disease? You'd be infecting the bird you vacciated!

"Live virus" vaccines typically use either a related virus that does not affect the species being vaccinated (it is similar enough to the condition you vaccinate against that the body's response provides immunity), or uses what is referred to as an attenuated virus. The latter retains the characteristics of the virus itself, and prompts the body to develop immunities to that virus, but the vaccine virus has been rendered non-infective (or in some cases, it reproduces, but exremely slowly).

Polio and measels vaccines are examples of live virus vaccines used for humans. Look up "attenuated virus" for more info on how these work. (There are issues with using some types of attenuated virus vacines, as remutations can occur ... but that's a whole 'nother story).

I don't know anything about chicken vaccination ... but from what I've been able to find, the original vaccine used HVT from turkeys to provoke an immune response,. Marek's has become resistant to that approach, and the vaccine you are likely to get now is a combination of HVT and attenuated MDV. That sounds fairly consistant with how "live vaccines" might be applied to human conditions, so I expect it's an accurate indication of how Marek's vaccinations work in chickens. Assuming that's correct, you could not cause Markek's with such a vaccine because you're injecting an attenuated Marek's.

It's an ongoing argument as to whether to vaccinate, or to try to breed for immunity, though.

As for mixing vaccinated chicks into a non-vaccinated flock, I would guess that the existing flock could harbor carriers, and could harm un-vaccinated chicks, but I don't think introducing vaccinated chicks would risk the existing flock any more than bringing in un-vaccinated chicks would. (Mareks' vaccination causes resistance in the vaccinated chick, but it does not sterilize, so you could still bring in Marek's even on a vaccinated chick).

If you chose to vaccinate, you could vaccinate your existing flock, and then either order vaccinated chicks, or vaccinate your chicks when they arrive.

I've not found vaccinations for small quantities of birds, but it still costs only a few $$ for the vaccine.

Mareks vaccine is a "leaky" vaccine, not a "perfect" vaccine. This means It protects the chicken that is vaccinated from developing the disease, but does not keep that chicken from spreading the disease to those who have not been vaccinated. So if you have a flock of chickens that half have been vaccinated and half have not, the have-nots are extra vulnerable.

 

[chickengeorgeto]

Marek's vaccine is usually administered at hatching time as a fine mist of water with the vaccine mixed in. The chicks then pick the tiny droplets of vaccine off of each others chick down. Besides there are 7 major strains of Marek's and each strain requires its own separate vaccine. Your birds will not get full blown Mareks form the vaccine but as I have previously indicated in a different post a blood test will be positive for Mareks but that tells you nothing. Because the positive test only means that your chicken is actively fighting off Marek's Disease.