I'm very sorry for your loss.
Many who have Marek's in their flock purchase vaccinated chicks and breed their own and don't neccessarily vaccinate those. The vaccine needs to be given at hatch, or in the egg before hatch and they cannot be exposed to the virus for 2 weeks, which is problematic for backyard keepers. Most vaccines come in 1000 dose vials or larger and the vaccine has to be used within a short time, no shelf life, so again, not very convenient for backyard keepers. Not trying to be discouraging, just how it is. Many simply try to breed for resistance, hatch from their own birds that are not symptomatic, waiting until they are a year or two old before hatching from them. That is a long term strategy, not a short term one. Egyptian Fayoumi birds are purportedly much more resistant to Marek's naturally, so adding some into breeding might help. Some strains are more virulent than others, so whatever strain you have may influence how you choose to deal with it. I've had Marek's in my flock for about 2 years, it breaks my heart every time I lose one. So far my strain has been very slow progression and losses have been managable. Egyptian Fayoumi's are on my wish list but I've not been able to find any close enough to purchase so far, I will not ship birds to my location due to issues with the postal service.....I don't like murdering birds needlessly.
This is a not terribly long article on Marek's and addresses the vaccine:
http://extension.msstate.edu/publications/marek’s-disease-backyard-chickens
This is another thread on this forum contributed to by people dealing with Marek's and trying to breed for resistance:
https://www.backyardchickens.com/th...ding-for-resistance-to-mareks-disease.894589/
