Curious how this 'u40s should be offered an alternative to AZ' thing is going to work practically speaking. As far as I'm aware, I thought pretty much every place only had one type of vaccine at hand, so is it even possible to offer an alternative? Will they suddenly start stocking two at most vaccine sites? Or will it be clear when booking which one will be available so u40s can choose based on this recommendation? Not complaining, just genuinely curious.