
I only recall one such post recently, a couple of weeks ago. As was said in that thread, as the protocol recommends some components to be given annually, annual reminders seem entirely appropriate.
I would have thought if any poster were finding their vets were not adopting the new protocol they surely would have posted by now either on that thread or the two recent ones, I don't recall anyone has.
When poster ask are boosters necessary why not just reply, yes, the protocol (devised with help by eminent and respected scientists) recommends it.
As I said previously I have since had the part/annual vaccine so my vets coffers will already be depleted for this year with no sign of her going out of business :)