So would I vaccinate my whole flock even though they probably already have it if my pullet did?
I doubt it would do the adults any good unless tht were vaccinated as chicks.. Some give boosters to adults that were vaccinated as chicks, but I don't know how much good it does or doesn't do.
The vaccination is easy. Reconstitute the vaccine as directed on the bottle. Draw the prescribed amount of vaccine into the needle. I believe it is .2ml, but I don't have my vaccine instructions in front of me so check that before giving the shot. Have a helper hold the chick. They will have to use one hand to try to immobilize the head. Swab the back of the neck with a swab of rubbing alcohol. This cleans the area and the wetness helps you to see the skin. Gently, grab a bit of neck fluff and lift the skin. Insert the needle being very careful not to go in one side and out the other. Inject the vaccine. The vaccine will make it look like there is a little bubble under the skin. When you insert the needle, the chick may squirm and squeak a bit. It is very important that your helper be ready for this. If the needle goes through both layers of skin, you may end up vaccinating the air and have to do it again. Some people inject the vaccine under the skin in the leg. The marek's vaccine is supposed to be given subcutaneously (just under the skin) and should not be jabbed into a muscle.
If you are having two hatch dates very close to each other you can get away with using one vial of vaccine. Split the pill in half and use half of the liquid suspension to reconstitute it. Use a sterilized container to mix it in. Put the other half of the liquid and unreconstituted pill in the fridge. It has a limited lifespan, but should be ok for a couple of weeks or so in the fridge. As for the reconstituted stuff, work quickly because it is only good for a half hour once it is mixed. My neighbor and I cut the vaccine into quarters last year and used it for a few hatches under the advice of an experienced poultry person on another forum that has successfully done it for years.
Some people wait as much as 5 days to vaccinate their chicks but keep the chicks quarantined during that time. I don't reccommend waiting, but if there was a delay in receiving the vaccine and the chicks had not been potentially exposed, I would still vaccinate them.
You can do this!!