Organic eggs all vaccinated... ?

I have only just realised (I know, I know...) that the lion mark on my Duchy Organics eggs means they have received the vaccine for salmonella. The heritage breed eggs from Waitrose have no lion mark though.

At my local farmers' market, I asked the stall holder (farm owner) about his organic eggs and he said although his were not Lion marked, they were tested for salmonella (fair enough) but *all* chickens in the UK are vaccinated for salmonella at 18 weeks - bar none. Organic or not, immaterial. Surely there must be a way to get unvaccinated eggs and chickens?! 

Help