Hi Juels
Both Fletch and Pip lived in a rural environment before coming to me. Pip was an outside dog in Ireland who regularly escaped and clearly knows how to catch small furry animals for his tea. As far as I know, rabbits and squirrels, although they obviously harbour diseases, don't have many that a dog, vacced or unvacced, would catch.
I'd be more concerned about Weils disease which is spread from rats and the rat population in cities is growing. As virtually everyone and everydog comes into contact with rats (city, town or country) whether they see them or not, I'd consider vaccing for that, if nothing else.
As I've said I do vaccs every year, but to be honest, wouldn't if I didn't do rescue and therefore put my dogs much more at risk from vacc diseases than other dogs. And I also don't kennel my dogs or have insurance policies to worry about. I stopped vaccing my rescue Jamie when he was 12 ish and even the vet agreed that it was pointless to continue (he lived for another 5years!)
I'm afraid only you can make the decision - and I don't envy you that decision.
Very best wishes
Hel