country, not everyone feeling the ease. it s just beyond our capacity to be able to care for all these patients. reporter: and tonight, as the w.h.o. marks the second anniversary of its declaring covid-19 a public health emergency of international concern, scientists have been tracking an omicron subvariant for weeks now, called ba.2, now detected in at least 29 states and accounting for less than 1% of all covid cases in the u.s. british researchers finding that vaccines appear to be just as effective against ba.2 as they are against the original ba.1 omicron. so far it looks like it s not more severe. reporter: the white house and fda are not confirming that timeline shared by dr. gottlieb with abc news. however, in december, pfizer said it would be testing three doses after the usual two shots did not appear to be as effective. ike, thank you. now to president biden weighing his pick to replace retiring supreme court justice stephen breyer. earlier this week, i spoke wit
u.k., and dr. fauch said we ll see cases go up in the united states, too. dr. elizabeth cohen joins us live. so put this in perspective. dr. fauci said he doesn t expect this to become a full surge. why is that? he didn t exactly say why he thinks this but there s a lot of hope because so many americans got the original omicron. the one that showed its head in the united states in december. so there is hope that may provide some protection against this cousin. let s look at a couple of the basics that we know about this variant called ba.2. we know it is 50 to 60% more transmissible, based on u.k. data. they re seeing much more of this subvariant. there s no evidence that it is any more severe than the original omicron variant. and that s great news.
more, people do not wear masks on transport, as a testing is scaled back as well, you will see infections pick up, that is one reason. perhaps the more important reason. perhaps the more important reason is this new offshoot, as it is called, of the omicron variant, called ba.2, which is proving to be even more contagious and transmissible than the version we saw at the christmas. we are really seeing that feed through to now. we have this weekly survey every friday from the office for national statistics in the uk, one in every 13 people would have tested positive for the virus last week. that is a record since they started with this survey in april 2020. that is 5 million people who would have tested positive in a single week, so these are quite significant numbers we have seen coming through. and are quite significant numbers we have seen coming through. and when we look at to. have seen coming through. and when we look at to. you have seen coming through. and when we look at to