Ive never had the kennel cough vaccine done on the basis i try 2 never put my dog in kennels and i must admit when leo was ill and his immune system was weak my old vet did think he had it.... But the lab boys had their first vaccines today and kennel cough was done as one of the routine vaccines

I do it as mine tend to mix in with a lot of other dogs on their walks, training and at shows. It can be picked up and passed around anywhere and not just in kennels.
Some people find it makes no difference to their dogs, so they can still get it, some find its a lesser strain of it and I personally have not had it in my boys, whether thats the innoculation working or not I don't know.

There have in the past couple of years been huge outbreaks of it and its not pleasant for any dog to have.

Someone will correct me if i'm wrong but most of the country had a huge outbreak last year sometime.

Kennels tend to want it done. Although I think there are a lot of different strains of it. At the moment it is not compulsary.

As I understand it, the KC vaccine is a bit like the flu vaccine, doesn't cover all strains. I also think it only lasts 3 or 6 months?  But it's not something I'd want done as a 'routine' vaccine, along with other boosters, specially without my knowledge or agreement it was being given as it's a live vaccine, so there is the possibility the dog may develop KC as a direct result of being given the vaccine. Doesn't happen in all cases, but I know a few it's happened to ... ironically one of them had it done in order to put her dog in kennels! :-(

Like the human cold or flu it is caused by different virus and it seems most dogs develop immunity to most strains. Could be that the strain you have a vaccine for is not the one they will come in contact with. However some kennels will insist that the dog is done before they will take them.

I usually have mine done as 2 of them are at shows so much.