Half of US 12- to 17-year-olds have received their first COVID-19 vaccine dose, and their vaccination rate is rising higher than any other age-group, said White House Coronavirus Response Coordinator Jeff Zients during a White House briefing today.Despite the milestone, concerns about the school year continue as the Delta variant (B1617.2) rips through the country: At the same briefing, Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky, MD, MPH, said yesterday's 7-day averages showed that COVID-19 cases, hospitalizations, and deaths have gone up 2.8%, 5.7%, and 11.0%, respectively.The United States reported 161,331 new COVID-19 cases and 1,292 deaths yesterday, according to the Johns Hopkins COVID-19 tracker.