concern. we've -- real reason for concern. we've seen that with scientists, with the aggressive response that some countries have been taken around travel bans. the answer is we don't know, but there are some concerning signs, some real cause for concern and for vigilance. the two things that have worried us about this particular variant are, number one, all the high number of 32 mutations on the spike protein, the part of the virus that the vaccine trains the immune system to fight. and so if, you know, some of our fears bear out, that would make the vaccines potentially less effective than they are right now. the second thing is that based on very limited evidence so far from the tremendous surveillance being done in southern africa, this variant appears to be out-competing the delta variant, at least in the area around johannesburg. and that suggests that it may be more transmissible or has a survival advantage. now remember, if we go back a few months to the spring/summer, there were a couple of different variants that we werre worried