If a dog has a fever or is sick... even mildly, it can affect a vaccine, and the proper antibodies won't be produced by the body.
The 1 and 3 year DHPP are the same, The 1 and 3 year Rabies are the same.
They are written as 1 year bc the dog needs to have 2 of each vaccine, DHPP and Rabies, given a year apart, in order to be considered protected. Once done, then the vaccines are written in the chart as 3 year DHPP and 3Year Rabies, even though they are the same vaccines that were given as 1 year vaccs.
Here is Dr Dodds' Protocol:
CANINE VACCINATION PROTOCOL – 2010
MINIMAL VACCINE USE W. Jean Dodds, DVM Note: The following vaccine protocol is offered for those dogs where minimal vaccinations are advisable or desirable. The schedule is one I recommend and should not interpreted to mean that other protocols recommended by a veterinarian would be less satisfactory. It's a matter of professional judgment and choice.
Age of Pups
----------------------
Vaccine Type
9 - 10 weeks------------------------------------------ Distemper + Parvovirus, MLV (e.g. Intervet
Progard Puppy DPV)
14 weeks -----------------------------------------------Same as above
16 -18 weeks (optional) -----------------------------Same as above (optional)
20 weeks or older, if allowable by law ----------Rabies
1 year -------------------------------------------------------Distemper + Parvovirus, MLV
1 year -------------------------------------------------------Rabies, killed 3-year product (give 3-4 weeks apart ) from distemper/parvovirus booster)
Perform vaccine antibody titers for distemper and parvovirus every three years thereafter, or more often, if desired. Vaccinate for rabies virus according to the law, except where circumstances indicate that a written waiver needs to be obtained from the primary care veterinarian. In that case, a rabies antibody titer can also be performed to accompany the waiver request.
**************** ************************ *******************
When you get a dog with an unknown vaccine history, they should get a DHPP and Rabies, then repeat in one year, then start the 3 year schedule.