I'm going to London soon. I'm doubly vaccinated, will be getting the train there and am not too worried about the risks of catching Covid on my trip generally but the one thing I am concerned about is the tube. My memories of it (pre-Covid) were that is was always very crowded and of course unventilated. How busy is it these days? I've found contradictory information online about how safe or not it is (re Covid transmission) but would be interested in hearing the experiences and views of people who have used it recently.