A vaccination site just for eligible union workers opened Monday in South Loop as Chicago moved into Phase 1C.

The city is now vaccinating an array of essential workers, with an estimated 84 percent of all adult Chicagoans eligible to get a shot as of Monday. The eligible groups include workers who often belong to unions — like construction and retail workers — and it’s those groups that will be able to get a shot at the new vaccination site.

The South Loop site at 2260 S. Grove St. will be able to vaccinate about 1,200 people per week, according to a Mayor’s Office news release. It’ll be appointment-only, with spots only open to workers who live or work in Chicago, have a current union card or are a union retiree and fall into the city’s eligible categories.

More information about getting an appointment at the site is available online.

The site will be able to do more vaccinations as more doses come to Chicago, according to the Mayor’s Office. The city’s supply is expected to increase significantly over the next few months; officials have said Chicago will have enough doses that anyone who is eligible will be able to get a shot by some point in May.

Chicago’s Phase 1C vaccinations also include legal workers, hairdressers, restaurant workers and more. Read the full list of who’s eligible here.

Workers are not required to use the vaccination site. They can still go elsewhere for their shots.