As Delta Variant Spreads, Iranâs President Warns of Fifth Wave Last Updated July 4, 2021, 2:10 a.m. ETJuly 4, 2021, 2:10 a.m. ET The Delta variant is causing concern in Iran and around the world. Americans are returning to their Fourth of July rituals. Six rescue workers at the Florida condo collapse site tested positive. Hereâs what you need to know: A sidewalk cafe in Tehran last month. Coronavirus cases in Iran have increased by 21 percent over the past two weeks.Credit...Morteza Nikoubazl/Agence France-Presse â Getty Images President Hassan Rouhani of Iran on Saturday warned that the country could see a fifth wave of coronavirus infections as the highly contagious Delta variant spreads.