given sequentially, so if you do them like maybe two or three times over a few day period, at the end of the day, they are as good as the pcr, but as a single test, they are not as sensitive, and when the fda came out and looked at what they did in stacking up against omicron, they said their sensitivity was diminished somewhat against omicron, but people should not get the impression that those tests are not valuable. they are very valuable. they're valuable for screening. they're valuable if you do them more than once in a sequential way to tell you whether or not you're infected. i think there was sort of a surge of concern when people said that, when it came out that the sensitivity was down, but they are still very valuable tests. >> okay. are cotton and surgical masks effective at preventing the spread of omicron? >> yes, when the cdc says they