On the latter, yes, there have been ongoing serologic surveys. That's why I also mentioned earlier on that it would be very important to know after this omicron wave what kind of immunity there is in the population.
But we also have to remember that the immune system is a complex thing, and so protection from infection is different from protection from serious outcomes. We're particularly concerned and very interested in protection against serious outcomes, for which the vaccines are actually doing quite well.
I think that protection from infection is going to be short-lived no matter whether you're infected with the virus itself or you have had a vaccination, so that remains to be monitored.