Health officials in southeastern Michigan are reporting a major increase in hepatitis A virus (HAV) cases over the last year, many of which have been linked to local restaurants. In response, Detroit is launching a series of pop-up mobile vaccination clinics and urging food establishments to get their workers a protective shot, The Daily Detroit reports.

Michigan is one of several states facing a hepatitis A outbreak that has sickened more than 1,300 people across the country, including in states like California, Utah and Colorado. Earlier this month, hundreds of customers of a Detroit McDonald’s and the city’s Greektown Casino were told they could be at risk for infection after employees tested positive for the virus. In the fall, employees at two other Detroit restaurants, Firewater Bar and Grill and a Little Caesars Pizza, spurred similar public health alerts.

Detroit’s first vaccine pop-up was held on Tuesday, December 19, at the University of Detroit’s Mercy Student Union. According to a press release, the city will host several more pop-ups over the coming year in areas with clusters of restaurants. 

In addition to targeting restaurant workers, the city is also pushing to vaccinate injection drug users and people experiencing homelessness. Detroit has also vaccinated all of its first responders, police officers, water and sewage department workers and others who routinely cross paths with populations at high risk for the virus or those who have the potential to contaminate local water supplies.

But the vaccines are not free. Employers are expected to pay $40 per employee for the vaccination, and employees are required to present a photo ID and a health insurance card at the clinic, which some fear may limit the initiative’s reach.