Just got the info today in the mail from the vet. Here's the message...
"We also reviewed flock management issues with Marek's, namely an "all-in, all-out" policy -- no new birds should be introduced and remaining birds should either be culled or allowed to live out their lives (and if clinical signs are seen, euthanized or treated symptomatically). Marek's is highly contagious, adn the virus is highly resistant in the environment, meaning that if theychoose to 'start over,' an entirely new site and coop should be used. Alternatiely, the existing area can be cleaned as well as possible, with removal of all organic debris and at least 6 inches of topsoil, and building interiors cleaned with a virucidal agent. Some sources also suggest allowing the area to lie fallow for 18-24 months. As for vaccination, the vaccine does NOT prevent infection, it only reduces mobidity; vaccinated birds tend to become carriers and intermittently shed the virus."
At this point, I'm going ahead and enjoying my existing three vaccinated chicks who are 6 weeks old. Hopefully, I won't lose more than anymore. Don't know if I'll have to go through this Marek's nightmare again or not.