kirsten grove, sarah bentley, thank you. >> thank you very much, brianna. >>> the mayor of houston sos about crowded places over the weekend, he's reversing course and taking action and he'll join us live to discuss that. >>> plus, as cases rise across the south, today in alabama, the new warning the health care system is at risk of running out of icu beds. >>> as we hear positive news about potential vaccines, a little bit of reality from one of the top groups that is working on one. hear oxford's new warning. >>> in his first public appearance in months, former vice president and presumptive presidential nominee joe biden left his home to commemorate memorial day. he was wearing a face mask. biden traveling to the delaware memorial bridge, veterans memorial park to lay a wreath. joined there by his wife, jill biden. there were dozens of veterans who were also in attendance. and this is, of course, a very personal day for biden. his oldest son, beau, an army vet who served in iraq and died of brain cancer in 2015. >>> i'm brianna keilar and you're watching cnn's special live coverage