Your vaccination protocol should be worked out based on where you live, your exposure rate (near by horses, horses coming and going off your property, etc.), health of your horses and overall risk for becoming ill.
ex. a horse boarded at a private facility, fairly consistent number of horses present VS a show horse with a heavy show schedule VS a horse on a private ranch hundreds of acres from the next horse VS a horse kept with number of horses or with neighbors that give marginal care.
There isn't (IMHO) one best answer on vaccination/care without taking your situation into consideration. Discuss it with your vet or research your area as to what you need to be aware of and then do a risk assessment.