the highly contagious delta variant now hitting every state in the u.s. tonight here, when those booster shots could roll out. dr. besser answering your questions. multiple tornadoes reported tonight as that system now moves up the east coast. tonight, concerns over flooding into the night from the south all the way up into new york. the tropical storm off bermuda. and the tropical storm slamming into haiti after that devastating 7.2 earthquake. ginger zee tracking all of this and matt gutman on the ground in haiti. a special edition of "world news tonight" begins now. good evening and it's great to have you with us here on a tuesday night. we do have a lot to get to. that new guidance expected soon on covid booster shots. a third shot for vaccinated americans. what we've learned tonight. and in a moment, dr. richard besser will join us. but we're going to begin tonight with the urgent race now to