Thank you for the informed and well considered answers.
I believe that the only vaccine that can be mandated in pets who are not going to be boarded anywhere is the rabies vaccine, because rabies poses a threat to humans. There are no zoonotic diseases that can be transmitted from dogs to humans that can be prevented by vaccinating them, so the DHLPP vaccine is not mandated.
It's not the vaccine itself that causes problems, it's the adjuvant. The adjuvant is a chemical protein the the vaccine that enhances the immune response, so it's not like vaccines can be given that don't have these chemical proteins in them. Some adjuvants have been implicated in injection site sarcomas, and it happened often enough that drug companies changed the protocol for administering the vaccines. It used to be that dogs and cats were vaccinated either in the scruff of the neck (for SubQ vaccines) and in the hip muscle (for IM vaccines). That has now changed, and all vaccines are given in the leg because if an injection site sarcoma develops, the leg can be amputated and the animal can be saved. You can't amputate anything if the tumor forms in the hip or the neck.
If your dogs are 7 years old and have received their vaccinations every year since puppyhood, chances are very good they will never again need another one unless you're going to send them into a situation, such as a boarding kennel, where their immune response could be severely challenged. In normal circumstances, however, they should have adequate coverage pretty much for the rest of their lives.
Jaybay was correct in saying that it's at least as expensive and maybe even a bit moreso to run titers than it is to vaccinate, however in the interest of lowering the risk of the animal developing injection site tumors, many owners are opting to just check the immune response rather than automatically vaccinating every year.
Most vets count on yearly vaccinations as a "gimme" when it comes to their income, so they will continue to send you the reminders that it's time to vaccinate, but the call, except in cases of rabies vaccinations, is entirely up to you.
Ghilly
Not entirely. One, you still have to follow local laws in your area, so if the law says you must vaccinate, you have to do it. Most areas now have a loophole though. IF your vet tests the blood levels and the results show the vaccine is still effective, then you may skip a year. The catch-22 is that the testing costs about as much as the vaccine, so you might end up paying for the testing AND the vaccines.
I seem to hear of more problems with vaccinations in cats than dogs; but reactions can happen to any person or animal with any medication.
The way I understand the problem is that the makers of the vaccine got FDA approval based on studies that showed the vaccines to be effective for one year. The vaccine gets produced and the manufacturer truthfully states that fact. After some number of years, more studies get done and determine the vaccines to be effective after 2, 3 or more years. Next thing you know, the manufacturer is served up some bad press or worse, slapped with lawsuits for price gouging when they were following the FDA laws in bringing their product to market.
Most cities and states also have loopholes for pets who have severe and consistent reactions to vaccines. In those cases a waiver can be obtained from the vet.
Sorry about the long-winded discussion! I'm sure Ghilly can give you even more detailed info on the whole vaccine controversy, but that's my understanding in a nutshell. :-)