Question about Marek's Vaccine (couldn't find answer on FAQ)

[Kiki]

Once it is opened I MUST be used... it will not keep mostly because it is a live virus.


I am unsure if that is 100% accurate.
It is my understanding (from back in the stone age) that there are about 7 major strains of herpes viruses that cause Marek's and a different vaccine is required to confer immunity to each strain. If that is true then it is entirely possiable to vaccinate for one strain and loose birds to a different strain.
The only way to breed resistance to this disease is to destroy any & all birds with it, and without mercy, because any bird that survives is a carrier.

Therefor by treating chickens with Marek's you are only selecting for or breeding chickens that will spread more Marek's throughout your flock and throughout your neighbors' flocks.

The vaccine link above even states that it prevents some symptoms of the disease...not the disease itself.