The United States is struggling to convince millions of people to get vaccinated against COVID-19, even as the Delta variant has proven to be especially contagious. Now the White House is recruiting an army of young TikTok influencers to help promote the vaccine. They’re posting interviews with Dr. Anthony Fauci on their pages. Ellie Zeiler, 17, said she was happy to help. In Chicago, the FBI is investigating reports of fake vaccine cards being used by some concert goers at Lollapalooza.