The Chicago Teachers Union is urging Chicago Public Schools to push back its planned April 19 reopening of high schools for in-person classes because of emerging COVID-19 variants and rising case counts.

Jesse Sharkey, the president of the union, expressed concerns on Wednesday surrounding the spread of COVID-19 among children and teenagers in states neighboring Illinois, saying, “This is precisely the age of people in this city who, in states around the country, … are driving the surge in other places,” the Chicago Sun-Times reported.