I used to just tet only and that was only every 2 or 3 years, depending on the strain of the jab but last year I put the boys onto the vet's health plan which includes both so that's what they got. I've now taken them off the health plans as part of it includes a load of worm counts and the new livery yard has a blanket worming plan (the ONLY thing that I don't like about it but appreciate why it has to happen because not all owners are conscientious!) so it is pointless to pay for something I don't use.
I've always had the babies given a full vaccination set from the start but then tended to drop the flu at the "booster" stage as none of mine ever went anywhere to mix with others. Although now that our finances are sorting, I will deffo be getting out and about next year so I will probs continue with both. Plus, of course, they are mixing with a lot more horses now so it makes sense to have them covered.
Also, I think that they have to be covered for both for my insurances to be valid.....