By law, the only vaccine that you are required to give to your dog is the rabies vaccine. It is also the only vaccine that MUST be administered by a licensed veterinarian. The laws vary by region, some places require rabies annually, some will let you get the shot every three years. If you have a dog with known health issues or vaccine reactions, you can often get a waiver from the vet exempting you from doing the rabies vaccine, too. The other vaccines do not need to be redone annually as long as there are still antibodies present, since you can’t create “more” immunity by vaccinating repeatedly. You can instead do “titers.” Titering refers to drawing blood, sending it to the lab to read the amount of antibodies present. If they are acceptable, you don’t need to revaccinate. It is more expensive than shots, though.