ungerleider, i want to ask you a question here.early 183 million americans, fully vaccinated, but there are rising concerns about the breakthrough cases -- breakthrough cases like we talked about apparently at "the view." this is michael asking how often does a person who has a breakthrough covid infection have long-term symptoms? >> we've seen the infection in unvaccinated individuals is 30% of those individuals continuing to have long haul covid symptoms. a small israeli study recently showed evidence that breakthrough infections could lead to long covid symptoms although this was a small study and a larger british one found 5% of people who had breakthrough infection had symptoms. it's a very good idea to get fully vaccinated even if you are young and healthy because we know long covid can lead to months of disabling symptoms even with a mild case. >> all right this will have to be the last one, dr. kass. school districts like new york city are requiring random weekly tests for unvaccinated students. linda is asking when will we