My experience as well. I will say though, that even vaccinated, some of these birds are showing poor feathering on their backs and I got my order on the 5th or 6th of May. Most are coming along fine but a few...not quite as well. Also they seem a bit behind on the laying part as well. I have had one pullet egg just the other day. Time will tell.
I ordered Silkies from McMurray this year and had them vaccinated as well. McMurray now does them and mine are doing awesome! Another thing to think about...you could order your 'Ameraucanas' from McMurray. I ordered some from them as I already have the full blooded ones so wanted to try something with the breeding end of things. A couple of them are EEs, no question, a couple look just like my true Ameraucanas and a couple look like and act like the Auraucanas [sp?]. The last two are nuts! As in flighty and a real pain in the butt. One of them decided to fly up 7' and start stripping the insulation off of the walls. Still, I know when she does start laying I will be getting the blue eggs I love so much. Just a thought...You can breed the EEs to go back to the Ameraucana traits they carry inside them. More than that though, if you want a flock that has natural immunities, add in some Dark Cornish and start hatching your own. My DCs survived the Marek's outbreak here last year. I lost one, but not to Marek's. All of the others were alive until i processed the extra roos a couple of weeks ago. there is something in their make up that keeps them safe.