The vaccination site is at the International Union of Operating Engineers Local 399 at 2260 S. Grove St., Lightfoot’s office said in a statement.
The site is open to union workers who live or work in Chicago who are eligible for vaccinations under Phase 1a, 1b and 1c guidelines.
"Since Chicago first received COVID-19 vaccines, our highest priority has been to vaccinate our most vulnerable residents and essential workers as quickly as possible," Lightfoot said in a statement.
The vaccination site was expected to administer 1,200 vaccinations per week, with additional capacity added as vaccine supply increases, the mayor’s office said.
For information about vaccine appointments, union members can visit www.chicagolabor.org/vaccine.