I got my first set of 5 chicks from a TSC here in Southern California in March 2018. We have had 3 die of Marek's disease (confirmed by necropsy at UC Davis) but my last 2 girls are doing great. They are unvaccinated though from what we were told by the sales person. I was wondering if it was ok to get more chicks even though we do have Marek's on our property? Is it possible to adopt or purchase vaccinated older hens? We are going to build a quarantine area for the new girls so we can keep them away for the recommended 30 days. I really love having chickens so I'm pretty bummed this happened to our 1st flock. Either the previous owners of this home had it or the chicks from TSC had it already.....either way it sucks. Thanks for your help!
Marek's should be expected to be on every property worldwide. Birds can be immune/resistant or succumb. They may live with the virus their whole lives and it may never present unless a stressor triggers it. Your last two birds are obviously resistant. You can get vaccinated birds whether chicks or adults.
It takes 2 weeks at least for the vaccine to become fully effective, so keep your chicks inside or away from dust and dander around the coop.