OP please please please vaccinate your dogs. They have a much greater chance of dying from one of the many preventable diseases out there, than they do of having an adverse reaction from a vaccine. You owe it to your dogs to keep them safe from disease - remember that naturally in the wild they would not die of old age, but from disease or injury. The natural method only works to an extent. A modern environment is far from natural and disease can spread quickly through populations of dogs.
If you truly want your dogs to live the longest life they can, please vaccinate them. The arguments against vaccination are myths - a functioning vaccine does not cause the disease it prevents, and the chemicals in a vaccine are not toxic and pass harmlessly through a dog's system. Don't be stubborn and please look at the objective facts. Don't make a point by gambling with your dogs' lives.
I would very much like to see this research, could you direct me to some of the sites you've been reading?I would also ask that in return, you respect my (very researched) opinion.