need for repeat vacinations

Question
I have always seen to it that my inside dogs were vaccinated each year.  Recently, a good friend had her older small breed vaccinated as usual and she had a serious reaction.  Since humans are only vaccinated once/twice in their life, how was it decided that dogs needed yearly vaccines?  Are there current thoughts on that?  I co-raise guide dogs for the blind and have them from ages 6-8wks to one year old.  If I don't vaccinate my pets, what are the consequences for the pups, if any?
Thanks for your opinion

Answer
Vaccine protocols initially were established based upon how long the vaccines were proven efficacious in testing done by the producers.  In recent years further study have been performed and the suggested guidelines are being adapted.

Presently after their first adult dose the recommendation would be for every 3 years repeating the vaccines.  Though the protection stays in their system longer this is now the experimentally proven time at which a level high enough to be effective has been shown.

If you do not vaccinate your dogs I do not see this as a problem for the puppies however over time the protection your dogs have against potential viruses brought in from the pups could fall low enough to no longer protect them.

I hope this helps.  Have a wonderful day.