Ask a vet for what vaccinations would be best to be given in your area. Sometimes it varies.
We do vaccinate all but two horses, I've only given a basic 5-way for the past many years though.
My dearly loved mare is allergic to any and every vaccination that we've tried. She has had reactions from her face swelling up like a balloon and inhibiting her ability to breathe to her muscles in the area that the shot was given being so sore that we literally have to force her to eat or drink, and in one case tube her due to colic because she wasn't drinking. She handles the basic $4 tet shot and she did fair well with her Prodigy vac when pregnant.
So for the past ten years we have not vaccinated her - she is 26 years old and still here
Her colt is the same way and so he does not get vaccinated either, he is now 8. I know of two farms that do not give any vaccinations and they have been around for years. Personal preference I suppose but I think that a tetanus vaccine is the absolute minimum and is a must for ALL animals.