I would say neither of the stories is 100% true.

Unvaccinated dogs can die from parvo.

Parvo virus is spread throughout the country, but is more of an issue in some areas than in others.

How dogs react to the parvo vaccine varies. Certain breeds including pitbulls, doberman pinschers, and rottweilers are more prone to catching parvo than some other breeds may be. Some feel those dogs need more frequent boosters than is currently recommended to protect them from the disease.

Stress depresses the immune system making it more likely for a dog to pick up an infection. So changing homes, exposure to dog show environments, being shipped to a pet store all might increase risks. But wildlife can carry parvo also so even being out in the country can't ensure you the dogs won't catch it.

The newer vaccination protocols suggest all puppy shots for deadly diseases be given and a booster be done every three years after the one year booster. You can read about this here

http://www.vetmed.wsu.edu/depts-vth/vaccinations.aspx

and about parvo here

http://www.marvistavet.com/html/canine_parvovirus.html

As I was a breeder as far back as when there were no parvo vaccines, I can tell you losing litters of pups and adult dogs to the disease is pretty awful. I do believe vaccinating against deadly diseases is better than losing a companion animal to the disease.

With any disease in any large population there often are individuals whose immune system can handle the infection but you might be better off being sure your dogs are protected than relying on the hope of innate immunity.

Hope this helps you!

I have been using the new protocol recommended of puppy shots, annual booster and then every three years a booster.

Exception is with the new Leptospirosis shot as that is for a bacterial infection not a viral infection and I've been doing that annually after the first two doses because its become a problem in my area.

Kennel cough nasal vaccine might be done every 6 months if your dogs are at high risk for exposure. The immunity to that is not as long lasting as some of the others.